Thank you so much. I was a FORD Master tech from 1979-1998. I own a 2009 F150 4x4. I didn't know the trucks use a vacuum system to operate the hubs. My 4x4 has not worked for 10 months. After watching your video I was able to pinpoint the problem to the vacuum senoid on the vacuum tank. I replaced it. It's working. Thank You.
So I very rarely look to RUclips for advice and have NEVER posted anything, but after this video, all bets are off. So I'm fairly mechanically inclined, but lazy and hate paying mechanics. So long story short, my ESOF has not worked for years. Again, being lazy and cheap, I just got out of the truck and manually locked the hubs when needed. Then I decided to look on RUclips and found this video. OMG. Followed it exactly and when I shifted to 4X4, the air to the front vent shut-off. I immediately went to look at the hoses leading to the hubs and within about 2 seconds, I found a big hole in the vacuum line that obviously was rubbing on metal. THANK YOU for not only saving me TIME but I'm sure probably $300-$500 at the shop. Perfectly produced video!!!!
thanks for the info. The part number is 7C3Z-9H465-A for people like me trying to freeze the video at the exact right moment! It's the same for my 2003 F-350. My problem is that the PVH gives vacuum to the hubs, but only for a couple of seconds. Research tells me it should give a vacuum for 45 seconds when you engage 4wd, and 15 seconds when you disengage. Just ordered a new PVH, hope it does the job. Thanks for making the video, it really helped!
Your video encouraged me to get the same vacuum gauge for like $50. It kept me from paying $130 for the diagnosis. All my lines are good, both hub seals are bad. 👍
Just an added bit of information for those who may not know. The heater/ac air distribution system on most vehicles has a blend door actuator that is vacuum operated. That's the troubleshooting connection between the vacuum operated front hub engagement system and the vehicle HVAC system. It's a clever and easy test to check for vacuum leaks. Well done.
03 Expedition 208k miles - This helped my solve a problem with my front left hub rattling as my truck shifted through second gear, it was trying to engage 4wd. -What I found after watching this vid was, There was a missing vac line coming from the passenger side firewall, (I think this was supposed to go to the battery to pull gasses out ) I found a small hard plastic line there on the firewall about a foot in from the side of the truck, - bundled in with some other vac lines, but with nothing hooked to it, and it was hissing slightly with the truck running.. so I plugged it with a small screw and problem solved, no more rattling in the left front hub. -Thanks!
Gotta say, if every mechanical problem was accompanied by a how-to-fix-it of this quality, mechanics would be out of business! Excellent excellent job, many thanks.
Were never to old to learn, someone on you tube has been there and done that, so thanks guy's for helping us old guy's out.I have something wrong with my 2004, 250 Ford want get out of 4x4. has 172k,but with your help i'll fix it... Thanks
Your video was a huge help. I was able to pin point the problem on my f-250 super duty in less than 20 min. $65.00 on ebay for an OEM PVH. One happy Hillbilly here. I just bought it a week ago.
A quick note of thanks. Your video helped me quickly find a similar problem. Turned out to be a vacuum line that cracked at the connector right after the valve.
Thank you!!!! This was the same thing that was wrong with mine. It saved me a lot of money by not taking it to the dealership. I bought one from a local autoparts place simply because I need the 4 wheel drive today and did not want to wait.
Hey Bob, great video! I was able to restore ESOF function on my 2000 F350 Lariat Dually CCLB just by following along with your video , total cost was around a $120.00 CAD ($95.00 USD) including a vacuum pump, 5' vacuum line and a PVH solenoid.
Very Very NICE! One of the best 4wd diagnostic videos on RUclips i've ever seen. Mine works but if it fails I'll know what to look for if it's a vacuum problem. Thanks Bob. Best Wishes n Blessings
Your video was very informative and saved me lots of money. But in an emergency when I could not get it to engage pneumatically I was not able to rotate the hub locks manually and had to get towed. I have a f-250 V-10 2000 with ESOF.
I have to agree with how useful this video is especially for this opening test sequence, and for sharing where everything is located. The 4WD indicator does not show for my 1998 F150 (it flashes on startup). I had hopes for something as easy as a fuse, but as the flashers work and they are on same fuse, I ruled out. The airblow test did not change when I turned the switch to 4W high, so it's on to checking the next suggestions in the video.
@@funbro1 This was beyond my skills and tools so resorted to taking to Ford dealer where I've had good service. They found the shift motor in the transfer case was dead, replaced. Not getting signal. Then traced to shift relay motor, reported dead and under a "mouse nest". Replaced. All worked but not responding to switch. Last was replacing a reported corroded fusebox and GEM (they had trouble finding one, I had to suggest eBay which I see people often use in Ford Forums). Truck is back in business, 800 miles before it turns 200k. If anyone knows a good Ford mechanic in Central Canada (SK) I'd like to know.
Sask I thought all guys from sask are basically mechanics as I am from a farm outside or P-dot A and stoon fortunately I was able to move BC Vancouver Island specifically to be honest I couldn't deal with the winters anymore lol I have a 03 f150 7700 with the 5.4 and it's got 579,778 km I keep it running great and it's never let me down but my 4x4 does not work hoping this video will help Did you ever find a good mechanic ? I know one in Saskatoon if you still need
Awesome Video Bob. Don't you wish you could get a 1% commision for all the money you have saved people since you uploaded this video. Great info and thank you!
One of the most straight forward and clear videos on this issue. Thank you!!!! I am diagnosing my 07 f250 as we speak. This is helping me big time. I’m hoping mine is the same issue.
Thanks Bob, we where just on a road trip in our truck and the A/C kept blowing out the defrost and every now and again the 4x4 light on the dash would flash. Hopefully we are heading in the right direction. Thanks!
How To Bob, Genius way to do initial check on vacuum by using the blower vent doors. Great video and appreciate your time to make it and provide a great service to us blue collar workers! I have a newer F150 (2013) and love my Fords but, for years they remain to have 4 wheel drive actuator issues and still can't seem to make a 4 wheel drive lock system to this day that is robust. Just blows my mind. I had mine in the dealership twice only to be told "we couldn't repeat the issue" Bet no one has ever heard that before. any way after many, many hours of research and some emails I was able (with the help of some other fine folks such as; yourself) determine the vacuum operated actuators were bad. Took my truck back to my dealer and forced them to watch some you tube videos. Pretty sad I have to show them a video on how to fix my truck. they replaced both actuators (after I forced the issue but, never did provide a root cause which, I think is BS (I asked the manager if a fuse blew in his house would he put a new one in and put a penny under it or would he try and find out what made it blow) LOL. I suspect from others information that water is getting into the vacuum system through the solenoid vent and damaging the actuator. Mine clicked/whirred and did this mainly when the temp dropped below 37 degrees F and was intermittent up until this year. I bought this truck new in Nov 2012 and noticed something around Jan/Feb 2013 and then was okay though the summer then as soon as winter hit again in 2014 the issue returned and progressively got worse and more often. Just thought I would add some info. Thanks for posting a great video!
Thanks for the video help, Almost took my 03' to a dealer till I watched this, 4x4 is working again, It was the part you replaced on yours. Thanks again.
Great video on troubleshooting. I would caution that just because a relay clicks, doesn't mean it's working. It just means that the coil inside is getting energized and a mechanical action is happening. However, a relay can click but still not work.
While this can be true conversely if a relay does not click there is a good chance that it does not work making this a good way to spot check a relay. Thanks for watching.
Subscribed. Thanks for posting. I will tackle my problem tomorrow. I noticed my AC kept blowing out of my defrost yesterday and today when I went to put my truck in 4x4 it would not engage.
acefoxtrot Sounds like that is your problem. You should have it fixed in no time at a fraction of the cost of taking it in. Thanks for watching. Glad to hear it was a help.
Had the same issue with my 2006 f250 . I just bought the truck with only 68k miles on it and it was bad. Replaced with the same part you did and works fine now! These must fail alot I guess.
Great video!! Ok here's my problem I have replaced hubs, PVH, tested vacuum and canister no leaks pump builds 14 in pressure, hubs hold 15 in pressure but I turn selector to 4x4 and one relay clicks and hubs lock...but when I switch back to 2x4 the other relay clicks and hubs don't unlock, for me to unlock hubs I have to turn hub to lock and back to auto on both sides and that free's the hubs up.
I know you said that you replaced the hubs but to me it sounds like everything is working except the hubs. Try taking the hubs apart and switch it on and off see what is holding the hubs in the locked position. Hope this helps.
I've picked up a few of these new from parts stores(next I will try the dealer), every time they wont hold a vacuum in the default position/2wd. Now I'm considering installing some kind of manual 3 way vacuum valve next to my 4x4 switch.
I'm having the same problem. I got a new from the parts store and it seems like its not working in the default position in 2wd. We're you able to fix the problem?
Thank you for the video. I have watched at least a dozen and yours was the best! I have a 2017 f250 diesel and I can't find the relays or the solenoid. Can you or someone assist. All of these videos are on older vehicles. A late model video would be great. Thank you again!
I have an isuse with my 4x4... the light won't come on when I switch into any 4hi or 4lo gear. Not getting any power to the t-case shift motor plug unless i jump the contacts of the relay by hand (still doesn't turn the motor) haven't yet bench tested the motor. The motor plug also show continuity between the contacts and ground but only with the relays plugged in. New relays btw. No vacuum issues as I have gone to manual WARN hubs and bypassed the vac lines. Air flow is fine. Thinking I have a bad GEM module and am just going to try to switch from ESOF to a custom floor shifter out of an older ford.
Great video! Just got my lifted f250 stuck in a small puddle pretty embarrassing lol. My 4x4 wasn't engaging but I really hope this could fix it. Thank you so much
It was a good video about the f-250. I have a f-150 with the IWE vacuum system not engaging 4WD. I guess also I’ve always thought differently about the 250’ s with manual locking hubs. It would be great if someone could explain that part, why need a vacuum system on that 4WD to engage whatever when they can be locked manually
It's just a convenience thing, you don't have to get out of the truck to set the 4 wheel drive. Good thing is that if the vacuum fails you can always lock the hubs. Thanks for watching.
That's very good information the only problem with that for me is the 4x4 light don't even come on for me... anyway I could maybe talk with you or email text about this problem im having? I checked all the fuses but can't seem to find any blown
Question, I followed your steps. I checked the vacuum at the PVH and I have @ 15 inches of vacuum. The vacuum at the hubs held. When I move the 4x4 switch from 2wd to 4wd I hear the motor engage the transfer case. After checking these what do I check next. I took the hub locks out, cleaned and greased them last week. No change. How do I test the solenoid? I rotated the front output shaft in 2wd and it spun free. In 4wd it rotated the front axle (hubs not engaged) I did the same with the truck running in 4wd hubs in lock. and the front axle turned. This should not have happened because the wheels were on the ground. Is this an indicator the hub locks are bad? I am guessing im correct, but looking for confirmation.
+Scott Sinclair The solenoids should make a clicking sound when it is energized (12V). You could switch the solenoids and see if that changes anything. If that does not change anything then I think you may have found the answer in the hub locks. Hope this helps. Thanks for watching.
Thanks for the video was very informative. My issue with my four wheel drive is, when I engage the switch to four wheel high/low drive the four wheel dash indicator doesn't turn on. I did try the vent-defroster test, but did not have the issue of defaulting to the defroster.
Great video thank you for posting. I ran this test on my Ford and a few things for me were different. For one my 4 by 4 does not engage and shows the same symptoms as this truck, the only difference being that when putting it in 4-wheel drive and having the air on the front and not defrost it never switches over to defrost. That being said, the hub's do not hold a vacuum and I'm not sure what to do next any help would be great thank you
@funbro1 I have no leaks (confirmed with tester) newt hub seals etc new solenoid. My vacuum will engage, but only for a minute. Then it disengaged. And ideas?
I had this same issue, i diagnosed with out a hand pump. Found blend door actuator leaking, vacuum hose broken at passenger knuckle, and and pvh solenoid leaking, phv solenoid is in the mail I am sure this will solve my issue to
So not to downplay your video or the information in it, just to add. In the beginning you talk about how if the relay “clicks” it’s good. The relay is just an electronic switch that closes two contacts when energized (some have 5 terminals with contact points in both on and off). These contacts can become dirty or get burn spots on them much like the contacts on a set of breaker points in older distributors. When this happens the relay will still “click” but sometimes can’t conduct current into the circuit bc of the high resistance on the contacts.
Well that is true when you dial down to it a real quick check if it is not clicking it will not be any good. There are also other ways to tell what is wrong with your system as shown in the video. Thanks for checking in.
old video but as everyone has stated, very well done. Is this the same process for a 04? just find the vac line and go for it in the order you did im assuming. Does the 04 do the same thing with the heater, vent and defrost? love the step by step explanations, sick and tired of videos that say "here is how you do such and such" and then jump to the final result lol
im looking for a video on a different problem, still watched and skipped through. if this ever happens on my 6.0 i know exactly where to find more info. great video
I have a 97 f150 with the shift on the fly 4x4. As far as I can tell I do not have a vacuum problem everything seems to check out, even the actuator on the front axle. The problem I have is it will not switch to 4x4 hi or low on the fly. In order for it to show 4x4 mode, the ignition key must be in the off position first. Once the ignition key is turned on, it will not switch to any 4x4 mode. Same with deselecting 4x4, the ignition has to be off before it changes 4x4 or 2x4 modes. In other words, any position I make for 4x4, the on the fly switch has to be selected before the ignition key is turned on. I cannot find any information on this problem anywhere, and as far as I can tell, no matter what I've checked the front axle will not engage, however the transfer case does and the front drive shaft will turn. Any ideas will be greatly appreciated.
Did I miss something? Was there no testing or diagnosis of the PVH shown? Obviously the repair worked but the diagnosis was by process of elimination without any testing of the failed part. I’m OK with this, I just wish the correct testing for the PVH had been shown in case that did not fix the problem in our case.
I've heard the vacuum for the hub locks is quite weak, but yours seems to move the needle on the vacuum gauge significantly. Can you tell me the spec on what the vacuum should be? Mine is also a 5.4L V8 so I don't have the vacuum pump on mine
Cpl. Chronic unfortunately I do not know what the required vacuum is to activate the hubs, on this video I went well above what I thought would be suffient to activate the hubs. Hope this helps.
Yes, follow the hoses around the vehicle starting at the PVH area. You will find several places where they plug together. Unplug one at a time with the pump running and see if the pumps stops after a little while, at that point you will know which hose may be leaking and you can trace that hose back more closely looking for a leak. If it helps you can take the glove box apart and remove it to gain access to the hoses from there. Hope this helps, good luck.
hello. can you help me, my vent air is blowing fine/ working fine even with the 4x4 switch on . no vacuum leak? my 4 wheel drive still not working unless i lock them in manually
Got stuck in the snow 4 times today because 4WD wasn't kicking in. Was afraid I was going to have to drive to the dealer and haggle to get them to honor the warranty. Now I can just take care of it myself.
HI BOB. DOES THE VACUUM HAVE TO WORK IF YOU HAVE MANUAL LOCKIN HUBS? I AM NOT GOING INTO 4 H OR 4L, WHEN I TURN THE 4 WHEEL DRIVE ON . THE 4 H LIGHT COMES ON BUT NOT THE 4L. THE PASSENGER SIDE HUB WILL TURN 360 PLUS DEGREES, AND NOT STOP WHEN THE ARROW LINES UP WITH THE DOT ON THE HUB. WHAT BRINGS IN THE ELECTRIC MOTOR ON THE XFER CASE. HOW WOULD YOU CHECK TO SEE IF THE XFER CASE MOTOR ENERGIZES? THANKS RANDY
I just performed the test with the vents and all worked fine. Could the switch be bad. The 4 wheel high works fine but the light will not even come on in 4 Low. It doesn't even engage in Low
***** I guess it's possible for the switch to be bad but I would check the relays first. They are all the same so they can be switched around to do a test. Also check the fuses both under the hood and under the dash. Hope this helps. Thanks for watching.
I believe I have the 4x4 losing vacuum intermittently while driving on the freeway and uphill, there is this horrible noise coming from the left front wheel. I have a 2008 Ford Expedition that has the same vacuum 4x4 system without the manual option. I was told that is normal for the pump to lose vacuum on acceleration but added a leak in my system it will release the hub to engage the 4x4. Any suggestions?
just found your video. wondering if you could shed some light... mine is an 03 Expedition. noticed that under load, the vent went to defrost/default mode. when not under load, vent operated. I found that if I bypass the 4x4 vac solenoid on the firewall on psgr side, the vent will work even under load. I then assumed there was a leak downstream of the 4x4 solenoid. Then I tried to put it into 4x4 hi or low and no dash light indicating the hubs are locking, and there is no actual 4x4 engaging. What might be your suggestion to test next? Thank you for your video.
I would start out with checking the vacuum at several different points to see if it is holding a vacuum. Also replacing the solenoids might be on the list, but if you bypassed them then that sounds like you covered the solenoids. Next I might check the hubs, they could be bad. Good luck, hope this helps
I have the same problem as you and changed the pulse vacuum solenoid just like you, and it fixed the air conditioning but not the 4x4. Any ideas on what I could do next?
I would start with the vacuum lines, If the vacuum generator runs "more than it should" the you have a leak in a line somewhere. I have seen this cause problems before and it's kinda hard to find. Next check the hubs and make sure they are working. This is where I would start hopefully you are able to find something. Thanks for watching
So, if the hubs are "stuck" in the locked position, removing the vacuum lines (i.e. causing leak) should release them, correct? What if they stay locked even after doing that?
Str8wirevideo The way I understand it is that the hubs receive a pulse from the vacuum that causes it to engage or dis engage, either way I would look at the hubs if you have checked for leaks in the vacuum system. Hope this helps. Thanks for watching.
Thanks Bob great video. I did the defrost check with no problems, checked relays next to driver battery and they looked good and I could hear them click in when I turned the switch to 4X4, pulled the double vacuum connector at the PHV Solenoid and could hear the vacuum tank drain and the vacuum pump started, put the connector back on and the pump stopped after maybe a minute, also could hear air flow at the vacuum tank when switching to 4 X 4. Any suggestions? FYI I tried to find the PVH price on line with no luck?
It is possible that your hubs could be the problem. You may want to take the hubs apart and look for any rust or corrosion that would keep them from moving. If after you have looked at the hubs and you still want to replace the PHV try eBay. I found one available from Heller Ford: www.ebay.com/sch/hellerfordparts/m.html?_nkw=&_armrs=1&_ipg=&_from=. Search (FORD OEM 1999-2010 FORD F-250,F-350 VACUUM CONTROL SOLENOID 4X4 FRONT HUBS)
funbro1 Thank you, I will borrow a vacumm pump from work today and test each side to the hub and back as you did. If that is good I will start to look into hub repair. FYI I did not hear the PHV engage but did hear air moving
funbro1 Using the manual vacuum pump I was able to hold 10" on the Hub lines at both sides but zero back towards the PVH. I could also hold 10" on the individual lines running away from the vacuum tank but test from the 2 hose connections at the tank it was zero. Testing the 2 hose connections from the PVH I had to pump a lot to get to 5" but then it held so I assume this is just due to the vacuum tank volume? Based on this I think I have a leak in the PVH, does that sound right? I was able to find the new OEM PVH for $67 freight included on EBAY. Thanks again. FYI the hubs work smooth manually
I’ve gotta problem where sometimes the two front wheels will make a noise that almost sounds like bearings. But I’m sure it’s something with the 4wd. Would you have any idea what it might be?
Great Info! Thank you How To Bob!! You helped me fix my venting / 4x4 engagement issue! One question regarding the 4x4 switch. My used but 'new to me' 07 F350 has no illumination behind the 2wd/4wdHigh/4wdLow curved panel. Wondering if this section is supposed to light up or not when my exterior lights are turned on? If so, can I simply change out a tiny bulb behind the "2x4/4x4" area or do I have to replace the whole square panel (which also include the rear back up sensor button and rear window switch in my case - both of those are illuminated)? Ford part number 5C34-25047A04-H. Thanks for any info or advice you may have!
I used a inexpensive vacuum pump. I think Auto Zone has a free rental for them...or at least they used to. Either way you should be able to find a cheap one to get your diagnosis done. Hope this helps, Thanks for watching.
I have a 2006 F150. When I turned the 4x4 shift knob sometimes it would work if I waited a few minutes but would stay in 4, now the indicator stopped coming on altogether, not working now. Shift motor out or vacuum problem? I need help.. Thanks Mike
There are so many things that this could be. Possibly a slow leak in one of the vacuum lines, the beginning of your PVH going bad, or the hubs could be rusty, dirty, or just sticking. If you live near an Autozone they will loan you a vacuum puller similar to the one in the video. Start by eliminating different parts of the vacuum system and work your way from there to the next possible problem. hope this helps. Check back and let us know how it goes. Thanks
Tried the vent / defrost test with high hopes, I have nothing but defrost in all settings. What does that mean ? "03" with 6.0 manual locks work, but not in cab selector. Lights are on as normal.
On my 2006 F350, the 4x4 cluster light comes on, but I do not have 4x4 when the hubs are in AUTO. One thing I noticed is my air does not change from vent to defrost like it shows in your video. However, the climate control system does change from air to defrost when I use the selector. Could this be the two relays? Or should I still consider the PVH solenoid. If I lock the hubs manually I do have 4x4, therefore I assume it isn't something at the transfer case. What are your thoughts?
Try removing 1 hose at a time while the PVH is running. Plug up the hole where the hose was removed and see if there is any difference with the PHV. if not go to the next hose and repeat. This may help you track down any leaks you may have. Hope this works for you. Thanks for watching.
Great video here are my results!! I Hope you can help!! I have the mighty vac same as yours. When I test the lines to the hubs it doesn't hold pressure so I know I need to replace those rubber lines. Then when I hook it up to the system to check back to the air reservoir and turn the key on I hear the pump but again no pressure at all (same thing with the other side) I have a new PVH solenoid, how do you know if the reservoir itself is cracked or bad? Thank you in advance Steve Seattle, WA It's a 99 Ford F250 super duty
I just had another vacuum leak long after I made this video. Finding leaks can be tricky. What I did was isolate each branch that was coming out of the reservoir by capping off the lines. Once I narrowed down which area kept the pump running I ended up tracing the lines for that branch. I ended up finding a small cut in the gray line and put a coupling on it to seal the leak. I hope this helps. Good luck.
that is the exact same problem i have i just changet the vacuum pump and got air to the vents but now whe i switch to 4x4 it does what your test does i will test it tomorrow thank you for the great info good job how to bob
Maybe you can give me some pointers I have a 200 F350 SOTF and the hubs don't seem to engage so I have been manually engaging them which is no problem I figure either the sol or I have a leak in the seal in the hubs. What is happning when I shift in to 4 Low some times it goes in but comes right back out but yesterday it shifted in and when I turned it back to 4x4 it stayed in 4 low I switched it several times ( with the brake pedal depressed) and then backed up and shut it off and let it set with the engine runnig and I know this doesent have anything to do with the vaccum because it's a deisl and has a vac pump. What could be going on with the 4x4 and 4 low? I use 4 low to pull my 35 foot camper up our very steep driveway. A buddy of mine told me up unplug something on the passanger firewall to keep the hubs from trying to lock so I would only have rear wheel drive and low range any clues there also? Any help would be appriciated. Mike
Mike Balloonman Without going step by step through each system on your truck it is very hard to diagnose your issue. Start with the solenoids. Next I would take the hubs apart and check them for operation and leaks. hope this help. Good luck and thanks for watching.
funbro1 Actually my question is on help with the transfer case hanging in 4 low and then coming out on it's own sometimes but Tuesday it wouldn't come out of 4 low when you turn the switch back to 4x4 the transfer case shifter is electric is it not?
***** Check the relays under the hood they should be the same so you can switch them out to do a little test, also check the fuses, both under the hood and under the dash. Hope this helps. Thanks for watching.
I seem to have an issue of he hub lock solenoid having a constant 12v applied to it no matter where my switch position is. The solenoid works (manually applied 12v to it) the shift selector on the dash appears to work, as the lights come on for 2wd, 4wd and 4-lo. I her the transfer case lock in and out when moving to 4, but I never have the solenoid power shifted to product the vacuum. Any suggestions? Since it appears to be getting power, fuses don't appear to be the issue. I'm not seeing an issue of concern with the ventilation switching. Potential relay issue?
Looks like my relays are good. Do you know if the PVH should always have the +12 on it, or only when activated by the switch? Mine is always hot, no matter the swtich position.
The PVH will have 12v going to it when it needs to turn on. If there is no vacuum it will cause the PVH to call for voltage. try taking out the hoses one by one and plug up the holes and see if anything changes. It may take a little tiime of the vacuum generator running to create enough vacuum to tell it to kick off so be patient. This might help eliminate a possible leak. hope this works for you.
Thanks - I'll give that a shot. I can hear the solenoid activate when I plug it, in plug it, so it's always getting +12. I've confirmed this when UNPLUGGING the PVH and using a multimeter, it always has +12. The pump does not always run either, but WILL run if I unplug the air lines from the PVH. I'll go thru the vac hoses again and see what I come up with.
I have a 2003 F150. My vent works, but I can't get heat out of the floor. Weather my 4x4 is on or off, I can get vent, and def, but no floor. My 4x4 light comes on, but no 4x4. When I go to 4l, I can hear the transfer case shift, but still no wheel action. Is this still a vacuum issue? and do I still look in the same places?.
+Eric G It sounds like it may still be a vacuum problem. You can trace all the vacuum lines back from the vacuum pump by unplugging them one at a time and putting your finger over the hole. If the pump stops you have found your leak.Plug the hose back in. From there follow that hose to another point that can be disconnected and repeat the process till you find the source of the leak. It can be hard to trace the hoses and time consuming. I have traced a leak back to the switching unit on the dash(The one that switches from floor to vent to defrost). I'm not 100% sure if a vacuum leak is the problem with the 4x4 but it does sounds like you still have a leak somewhere. Hope this helps, Good luck.
It helps a little bit. I do not have a vacuum pump that I can find. I did test vacuum on the 4x4 cylanods and have great pressures when and where I should. I was able to get underneath the truck today and the actuator is moving back and forth just find. How ever, there is a vacuum line that goes into the housing above the actuator, and do not have vacuum on it in either 2 or 4 mode. I will have to get underneath it when I have dry ground after I find out when I should have vacuum on that line. I am hoping that is the answer.
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Thank you so much. I was a FORD Master tech from 1979-1998. I own a 2009 F150 4x4. I didn't know the trucks use a vacuum system to operate the hubs. My 4x4 has not worked for 10 months. After watching your video I was able to pinpoint the problem to the vacuum senoid on the vacuum tank. I replaced it. It's working. Thank You.
of the thousands out there... this video is by far the most informative. Not all fluff, actual troubleshooting ideas. Very good. thank you.
Yea too many people just talk and talk and talk.
So I very rarely look to RUclips for advice and have NEVER posted anything, but after this video, all bets are off. So I'm fairly mechanically inclined, but lazy and hate paying mechanics. So long story short, my ESOF has not worked for years. Again, being lazy and cheap, I just got out of the truck and manually locked the hubs when needed. Then I decided to look on RUclips and found this video. OMG. Followed it exactly and when I shifted to 4X4, the air to the front vent shut-off. I immediately went to look at the hoses leading to the hubs and within about 2 seconds, I found a big hole in the vacuum line that obviously was rubbing on metal. THANK YOU for not only saving me TIME but I'm sure probably $300-$500 at the shop. Perfectly produced video!!!!
Awesome! Glad you were able to use the video. Love to hear a good success story. Thanks for watching.
thanks for the info. The part number is 7C3Z-9H465-A for people like me trying to freeze the video at the exact right moment! It's the same for my 2003 F-350. My problem is that the PVH gives vacuum to the hubs, but only for a couple of seconds. Research tells me it should give a vacuum for 45 seconds when you engage 4wd, and 15 seconds when you disengage. Just ordered a new PVH, hope it does the job. Thanks for making the video, it really helped!
Adrian Edwards Thanks for the little extras of info, hopefully this will fix your issue. Thanks for watching.
Your video encouraged me to get the same vacuum gauge for like $50. It kept me from paying $130 for the diagnosis. All my lines are good, both hub seals are bad. 👍
Just an added bit of information for those who may not know. The heater/ac air distribution system on most vehicles has a blend door actuator that is vacuum operated. That's the troubleshooting connection between the vacuum operated front hub engagement system and the vehicle HVAC system. It's a clever and easy test to check for vacuum leaks. Well done.
Yes, This is an easy way to find out if you have a vacuum leak. The hard part may be finding the actual leak. Thanks for checking in.
03 Expedition 208k miles - This helped my solve a problem with my front left hub rattling as my truck shifted through second gear, it was trying to engage 4wd.
-What I found after watching this vid was, There was a missing vac line coming from the passenger side firewall, (I think this was supposed to go to the battery to pull gasses out )
I found a small hard plastic line there on the firewall about a foot in from the side of the truck, - bundled in with some other vac lines, but with nothing hooked to it, and it was hissing slightly with the truck running.. so I plugged it with a small screw and problem solved, no more rattling in the left front hub. -Thanks!
Nice job, Thanks for watching.
Fixed my 2001 7.3 today after watching this video. Turned out the relay fuse was bad. One was bad Thanks
Gotta say, if every mechanical problem was accompanied by a how-to-fix-it of this quality, mechanics would be out of business! Excellent excellent job, many thanks.
Chris Tann Thanks for that, and thanks for watching.
Were never to old to learn, someone on you tube has been there and done that, so thanks guy's for helping us old guy's out.I have something wrong with my 2004, 250 Ford want get out of 4x4. has 172k,but with your help i'll fix it... Thanks
Best of luck and thanks for watching.
This video is EXACTLY what I was looking for and should be an example for other 'how to troubleshoot' videos. Very well done.
Awesome, glad it was helpful.
Thanks for watching.
This guy actually has troubleshooting skills. Bravo dude, good work!
+Johnymatic Thank you, Hopefully the video was a help to you.
Your video was a huge help. I was able to pin point the problem on my f-250 super duty in less than 20 min. $65.00 on ebay for an OEM PVH. One happy Hillbilly here. I just bought it a week ago.
yz4twntee That's awesome, Think of the money that you just saved.
A quick note of thanks. Your video helped me quickly find a similar problem. Turned out to be a vacuum line that cracked at the connector right after the valve.
That's great to hear. Saving money is always good. Thanks for watching.
Thank you for this video! You saved me lots of time and money from taking my truck to the shop.
Awesome! I love saving money. Thanks for watching.
Thank you!!!! This was the same thing that was wrong with mine. It saved me a lot of money by not taking it to the dealership. I bought one from a local autoparts place simply because I need the 4 wheel drive today and did not want to wait.
Awesome!, easy fix once you know what is wrong. Glad it worked for you. Thanks for watching.
Quick question. If all that is working. Do you leave your hubs in auto or locked at all times? I'm new to all this
@@shawngonzales5080 Auto if there locked it should work no matter the vacuum.
Just saved me a massive headache... thank you for such a great video.
+Travis O Awesome, Thanks for watching.
Hey Bob, great video! I was able to restore ESOF function on my 2000 F350 Lariat Dually CCLB just by following along with your video , total cost was around a $120.00 CAD ($95.00 USD) including a vacuum pump, 5' vacuum line and a PVH solenoid.
+Roger Bannister Very nice! Thanks for watching.
I just watched this video and was able to fix on my own, it was the relay on my 2005 ford F350. Thank you.
I love it. Think of the money you saved. Thanks for watching.
Very Very NICE! One of the best 4wd diagnostic videos on RUclips i've ever seen. Mine works but if it fails I'll know what to look for if it's a vacuum problem. Thanks Bob. Best Wishes n Blessings
+Keith Noneya Thanks for watching.
Your video was very informative and saved me lots of money. But in an emergency when I could not get it to engage pneumatically I was not able to rotate the hub locks manually and had to get towed. I have a f-250 V-10 2000 with ESOF.
I had to do the same so I figured it’s time to fix it.
Thanks for watching.
I had already isolated it the same way you did before I found your video but you confirmed my suspicions...thank you!
Thanks for watching.
I have to agree with how useful this video is especially for this opening test sequence, and for sharing where everything is located. The 4WD indicator does not show for my 1998 F150 (it flashes on startup). I had hopes for something as easy as a fuse, but as the flashers work and they are on same fuse, I ruled out. The airblow test did not change when I turned the switch to 4W high, so it's on to checking the next suggestions in the video.
Hope you figure out what the issue is, check back with us when you do so we know what you found. Thanks for watching.
@@funbro1 This was beyond my skills and tools so resorted to taking to Ford dealer where I've had good service. They found the shift motor in the transfer case was dead, replaced. Not getting signal. Then traced to shift relay motor, reported dead and under a "mouse nest". Replaced. All worked but not responding to switch. Last was replacing a reported corroded fusebox and GEM (they had trouble finding one, I had to suggest eBay which I see people often use in Ford Forums). Truck is back in business, 800 miles before it turns 200k. If anyone knows a good Ford mechanic in Central Canada (SK) I'd like to know.
@@cogdog Sounds like you have a laundry list of things going on there, I wish you the best. Thanks for the view.
Sask I thought all guys from sask are basically mechanics as I am from a farm outside or P-dot A and stoon fortunately I was able to move BC Vancouver Island specifically to be honest I couldn't deal with the winters anymore lol I have a 03 f150 7700 with the 5.4 and it's got 579,778 km I keep it running great and it's never let me down but my 4x4 does not work hoping this video will help
Did you ever find a good mechanic ? I know one in Saskatoon if you still need
@@spitfire260381 Thanks, my 4WD has been working great since this fix. Pretty essential for grid roads and the slippery ones in Moose Jaw.
Getting ready to troubleshoot my 02 , had banging noise then took a shit. Thanks for the game plan.
Hopefully that is it and it is a quick repair.
Awesome Video Bob. Don't you wish you could get a 1% commision for all the money you have saved people since you uploaded this video. Great info and thank you!
Sounds good to me. Thanks for watching.
great troubleshooting procedure.....you make it look easy, Bob....you da' man!!!....thanks!!
Thanks for watching.
God I love RUclips and the fixes I find. Thank you!
Glad it was a help, Thanks for watching.
One of the most straight forward and clear videos on this issue. Thank you!!!! I am diagnosing my 07 f250 as we speak. This is helping me big time. I’m hoping mine is the same issue.
Glad it was helpful, thanks for watching.
Thanks Bob, we where just on a road trip in our truck and the A/C kept blowing out the defrost and every now and again the 4x4 light on the dash would flash. Hopefully we are heading in the right direction. Thanks!
It's an easy fix and doesn't cost too much. Thanks for watching.
How To Bob, Genius way to do initial check on vacuum by using the blower vent doors. Great video and appreciate your time to make it and provide a great service to us blue collar workers! I have a newer F150 (2013) and love my Fords but, for years they remain to have 4 wheel drive actuator issues and still can't seem to make a 4 wheel drive lock system to this day that is robust. Just blows my mind. I had mine in the dealership twice only to be told "we couldn't repeat the issue" Bet no one has ever heard that before. any way after many, many hours of research and some emails I was able (with the help of some other fine folks such as; yourself) determine the vacuum operated actuators were bad. Took my truck back to my dealer and forced them to watch some you tube videos. Pretty sad I have to show them a video on how to fix my truck. they replaced both actuators (after I forced the issue but, never did provide a root cause which, I think is BS (I asked the manager if a fuse blew in his house would he put a new one in and put a penny under it or would he try and find out what made it blow) LOL. I suspect from others information that water is getting into the vacuum system through the solenoid vent and damaging the actuator. Mine clicked/whirred and did this mainly when the temp dropped below 37 degrees F and was intermittent up until this year. I bought this truck new in Nov 2012 and noticed something around Jan/Feb 2013 and then was okay though the summer then as soon as winter hit again in 2014 the issue returned and progressively got worse and more often. Just thought I would add some info. Thanks for posting a great video!
thackmd Glad you liked the video. Thanks for watching.
Qui Hoggin know y use I o OK g yip up a ru in I him a
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Thanks for the video help, Almost took my 03' to a dealer till I watched this, 4x4 is working again, It was the part you replaced on yours. Thanks again.
I'm glad to hear you were able to fix your ESOF by yourself. You saved a lot of money that way. :-) Thanks for watching.
@@funbro1 once all that is working. Do you leave your hubs in locked or auto position? At all times where should your hub locker be?
@@funbro1 once all that is working. Do you leave your hubs in locked or auto position? At all times where should your hub locker be?
Great video on troubleshooting. I would caution that just because a relay clicks, doesn't mean it's working. It just means that the coil inside is getting energized and a mechanical action is happening. However, a relay can click but still not work.
While this can be true conversely if a relay does not click there is a good chance that it does not work making this a good way to spot check a relay. Thanks for watching.
Subscribed. Thanks for posting. I will tackle my problem tomorrow. I noticed my AC kept blowing out of my defrost yesterday and today when I went to put my truck in 4x4 it would not engage.
acefoxtrot Sounds like that is your problem. You should have it fixed in no time at a fraction of the cost of taking it in. Thanks for watching. Glad to hear it was a help.
fantastic video - just wish i watched before i took it to the garage to address my issue.
Had the same issue with my 2006 f250 . I just bought the truck with only 68k miles on it and it was bad. Replaced with the same part you did and works fine now! These must fail alot I guess.
Thanks for watching.
Perfect, thanks for the info. That saved me a boat load of time.
+Richard Nordell Thanks for watching
Superb detail. Very clear explanations. I learned a lot. Thank you!
Thanks for watching.
Thanks for the time you spent on this demo.
Now I know what to look for. cheers.
Hopefully you can fix it easily and save a lot of money. Good luck. Thanks for watching.
Great video!! Ok here's my problem I have replaced hubs, PVH, tested vacuum and canister no leaks pump builds 14 in pressure, hubs hold 15 in pressure but I turn selector to 4x4 and one relay clicks and hubs lock...but when I switch back to 2x4 the other relay clicks and hubs don't unlock, for me to unlock hubs I have to turn hub to lock and back to auto on both sides and that free's the hubs up.
I know you said that you replaced the hubs but to me it sounds like everything is working except the hubs. Try taking the hubs apart and switch it on and off see what is holding the hubs in the locked position. Hope this helps.
I've picked up a few of these new from parts stores(next I will try the dealer), every time they wont hold a vacuum in the default position/2wd. Now I'm considering installing some kind of manual 3 way vacuum valve next to my 4x4 switch.
That could work. Thanks for viewing.
I'm having the same problem. I got a new from the parts store and it seems like its not working in the default position in 2wd. We're you able to fix the problem?
Thank you for the video. I have watched at least a dozen and yours was the best! I have a 2017 f250 diesel and I can't find the relays or the solenoid. Can you or someone assist. All of these videos are on older vehicles. A late model video would be great. Thank you again!
If I ever come across a newer truck that needs this done I will definitely post a video for you. Thanks for watching
I have an isuse with my 4x4... the light won't come on when I switch into any 4hi or 4lo gear. Not getting any power to the t-case shift motor plug unless i jump the contacts of the relay by hand (still doesn't turn the motor) haven't yet bench tested the motor. The motor plug also show continuity between the contacts and ground but only with the relays plugged in. New relays btw. No vacuum issues as I have gone to manual WARN hubs and bypassed the vac lines. Air flow is fine. Thinking I have a bad GEM module and am just going to try to switch from ESOF to a custom floor shifter out of an older ford.
Sounds like you covered a bunch of things, I wish you the best of luck getting your 4WD working correctly. Thanks for watching
Great video! Just got my lifted f250 stuck in a small puddle pretty embarrassing lol. My 4x4 wasn't engaging but I really hope this could fix it. Thank you so much
Daniel Lozano Hope this is what is causing your issue, It is a quick easy fix. Let us know how it goes. Thanks for watching
Great video! Thanks I'm having the same problem. Now I can go diagnose and fix it.
Awesome, Thanks for watching.
It was a good video about the f-250. I have a f-150 with the IWE vacuum system not engaging 4WD. I guess also I’ve always thought differently about the 250’ s with manual locking hubs. It would be great if someone could explain that part, why need a vacuum system on that 4WD to engage whatever when they can be locked manually
It's just a convenience thing, you don't have to get out of the truck to set the 4 wheel drive. Good thing is that if the vacuum fails you can always lock the hubs. Thanks for watching.
Thanks for the reply funbro1. I also like to mention I really liked your video and advise.
That's very good information the only problem with that for me is the 4x4 light don't even come on for me... anyway I could maybe talk with you or email text about this problem im having? I checked all the fuses but can't seem to find any blown
Are you getting the defrost symptom? It is also possible that a relay is bad.
Question, I followed your steps. I checked the vacuum at the PVH and I have @ 15 inches of vacuum. The vacuum at the hubs held. When I move the 4x4 switch from 2wd to 4wd I hear the motor engage the transfer case. After checking these what do I check next. I took the hub locks out, cleaned and greased them last week. No change. How do I test the solenoid?
I rotated the front output shaft in 2wd and it spun free. In 4wd it rotated the front axle (hubs not engaged) I did the same with the truck running in 4wd hubs in lock. and the front axle turned. This should not have happened because the wheels were on the ground. Is this an indicator the hub locks are bad? I am guessing im correct, but looking for confirmation.
+Scott Sinclair The solenoids should make a clicking sound when it is energized (12V). You could switch the solenoids and see if that changes anything. If that does not change anything then I think you may have found the answer in the hub locks. Hope this helps. Thanks for watching.
Could that still be the issue even with manual locking hubs
My manual locking hubs work fine. But not my esof
Yes it is possible that this could be the issue.
Thanks for the video was very informative. My issue with my four wheel drive is, when I engage the switch to four wheel high/low drive the four wheel dash indicator doesn't turn on. I did try the vent-defroster test, but did not have the issue of defaulting to the defroster.
You could have a problem in the actual hubs if all your vacuum lines tested out good. Try checking the relays also.
Great video thank you for posting. I ran this test on my Ford and a few things for me were different. For one my 4 by 4 does not engage and shows the same symptoms as this truck, the only difference being that when putting it in 4-wheel drive and having the air on the front and not defrost it never switches over to defrost. That being said, the hub's do not hold a vacuum and I'm not sure what to do next any help would be great thank you
@funbro1 I have no leaks (confirmed with tester) newt hub seals etc new solenoid.
My vacuum will engage, but only for a minute. Then it disengaged.
And ideas?
Great video, easy to understand, no BS. Subscribed!!
Thanks for watching
Just fixed my 2007 F250's 4wd by doing what you taught us in this video! Thanks for sharing this.
Awesome!
excellent video. Clear and precise info. Good job!!!
Thanks for watching
Thanks for sharing.. Exactly what I needed to see. Mine works if you put them in manual lock..just not auto lock. Will be tackeling this soon.
Thanks for watching
I had this same issue, i diagnosed with out a hand pump. Found blend door actuator leaking, vacuum hose broken at passenger knuckle, and and pvh solenoid leaking, phv solenoid is in the mail I am sure this will solve my issue to
Varro Good to hear. Thanks for watching.
Thanks for the video!!
Just wondering if it is the same thing for an '07 F150?
Sometimes my 4x4 will work and others not.....
Try the vent test to see if you are losing vacuum, That should be the same. Thanks for watching.
Good video. Basic and to the point.
Thanks for watching.
I have 2020 f250, doesn't want to turn on automatically, have to go out and do it manually. Thanks for the video, I will check it now.
I wish you the best, thanks for watching.
So not to downplay your video or the information in it, just to add. In the beginning you talk about how if the relay “clicks” it’s good. The relay is just an electronic switch that closes two contacts when energized (some have 5 terminals with contact points in both on and off). These contacts can become dirty or get burn spots on them much like the contacts on a set of breaker points in older distributors. When this happens the relay will still “click” but sometimes can’t conduct current into the circuit bc of the high resistance on the contacts.
Well that is true when you dial down to it a real quick check if it is not clicking it will not be any good. There are also other ways to tell what is wrong with your system as shown in the video. Thanks for checking in.
old video but as everyone has stated, very well done. Is this the same process for a 04? just find the vac line and go for it in the order you did im assuming. Does the 04 do the same thing with the heater, vent and defrost?
love the step by step explanations, sick and tired of videos that say "here is how you do such and such" and then jump to the final result lol
I believe it should be the same from 2003 through 2007. Hope this helps, thanks for watching.
im looking for a video on a different problem, still watched and skipped through. if this ever happens on my 6.0 i know exactly where to find more info. great video
Good deal, thanks for watching.
Excellent video Bob..Thanks for the tip..
Thanks for watching.
I have a 97 f150 with the shift on the fly 4x4. As far as I can tell I do not have a vacuum problem everything seems to check out, even the actuator on the front axle. The problem I have is it will not switch to 4x4 hi or low on the fly. In order for it to show 4x4 mode, the ignition key must be in the off position first. Once the ignition key is turned on, it will not switch to any 4x4 mode. Same with deselecting 4x4, the ignition has to be off before it changes 4x4 or 2x4 modes. In other words, any position I make for 4x4, the on the fly switch has to be selected before the ignition key is turned on. I cannot find any information on this problem anywhere, and as far as I can tell, no matter what I've checked the front axle will not engage, however the transfer case does and the front drive shaft will turn. Any ideas will be greatly appreciated.
Sorry I have no ideas, :-(
your video is great. thanks But why does the truck have lock in hubs and vacuum hubs
If something were to happen to the vacuum hubs (like in this video) you could lock the hubs and still have 4WD. Thanks for watching
oh yea my bad LOL
Did I miss something? Was there no testing or diagnosis of the PVH shown? Obviously the repair worked but the diagnosis was by process of elimination without any testing of the failed part. I’m OK with this, I just wish the correct testing for the PVH had been shown in case that did not fix the problem in our case.
The system was vacuum tested and everything was good, the hubs worked so I went to the next obvious thing. Thanks for watching.
I've heard the vacuum for the hub locks is quite weak, but yours seems to move the needle on the vacuum gauge significantly. Can you tell me the spec on what the vacuum should be? Mine is also a 5.4L V8 so I don't have the vacuum pump on mine
Cpl. Chronic unfortunately I do not know what the required vacuum is to activate the hubs, on this video I went well above what I thought would be suffient to activate the hubs. Hope this helps.
funbro1 The F-150 does not have a vac pump it gets it's vac off the engine.
So my vent blows in two and four wheel drive. Does this mean that the engager motor needs to be replaced?
That means that you do not have a vacuum leak. It is time to start searching for another issue possibly the motor, yes. Thanks for watching.
So where should I look if there are no leaks on the 4 wheel side? Pump work great and replaced the pvh...should the cab side hold vacuum?
thnx
Yes, follow the hoses around the vehicle starting at the PVH area. You will find several places where they plug together. Unplug one at a time with the pump running and see if the pumps stops after a little while, at that point you will know which hose may be leaking and you can trace that hose back more closely looking for a leak. If it helps you can take the glove box apart and remove it to gain access to the hoses from there. Hope this helps, good luck.
hello. can you help me, my vent air is blowing fine/ working fine even with the 4x4 switch on . no vacuum leak? my 4 wheel drive still not working unless i lock them in manually
I would start looking at the hubs, they could be seized. Hope this helps, thanks for watching.
Got stuck in the snow 4 times today because 4WD wasn't kicking in. Was afraid I was going to have to drive to the dealer and haggle to get them to honor the warranty. Now I can just take care of it myself.
Awesome, do it. Thanks for watching.
great video i just used it to find my issue....keep it up!!!
That is great to hear. Thanks for watching.
HI BOB. DOES THE VACUUM HAVE TO WORK IF YOU HAVE MANUAL LOCKIN HUBS? I AM NOT GOING INTO 4 H OR 4L, WHEN I TURN THE 4 WHEEL DRIVE ON . THE 4 H LIGHT COMES ON BUT NOT THE 4L. THE PASSENGER SIDE HUB WILL TURN 360 PLUS DEGREES, AND NOT STOP WHEN THE ARROW LINES UP WITH THE DOT ON THE HUB. WHAT BRINGS IN THE ELECTRIC MOTOR ON THE XFER CASE. HOW WOULD YOU CHECK TO SEE IF THE XFER CASE MOTOR ENERGIZES? THANKS RANDY
YOU SHOULD STILL BE ABLE TO LOCK THE HUBS IN MANUALLY.
I just performed the test with the vents and all worked fine. Could the switch be bad. The 4 wheel high works fine but the light will not even come on in 4 Low. It doesn't even engage in Low
***** I guess it's possible for the switch to be bad but I would check the relays first. They are all the same so they can be switched around to do a test. Also check the fuses both under the hood and under the dash. Hope this helps. Thanks for watching.
Great video sir! This is super helpful. Thanks
Glad to help, thanks for watching.
I believe I have the 4x4 losing vacuum intermittently while driving on the freeway and uphill, there is this horrible noise coming from the left front wheel. I have a 2008 Ford Expedition that has the same vacuum 4x4 system without the manual option. I was told that is normal for the pump to lose vacuum on acceleration but added a leak in my system it will release the hub to engage the 4x4. Any suggestions?
+Alin Cosma Best bet would be to track down that leak using a vacuum generator, Hopefully it is just a hose not the seal around the hub area.
just found your video. wondering if you could shed some light... mine is an 03 Expedition. noticed that under load, the vent went to defrost/default mode. when not under load, vent operated. I found that if I bypass the 4x4 vac solenoid on the firewall on psgr side, the vent will work even under load. I then assumed there was a leak downstream of the 4x4 solenoid. Then I tried to put it into 4x4 hi or low and no dash light indicating the hubs are locking, and there is no actual 4x4 engaging. What might be your suggestion to test next? Thank you for your video.
I would start out with checking the vacuum at several different points to see if it is holding a vacuum. Also replacing the solenoids might be on the list, but if you bypassed them then that sounds like you covered the solenoids. Next I might check the hubs, they could be bad. Good luck, hope this helps
I have the same problem as you and changed the pulse vacuum solenoid just like you, and it fixed the air conditioning but not the 4x4. Any ideas on what I could do next?
I would start with the vacuum lines, If the vacuum generator runs "more than it should" the you have a leak in a line somewhere. I have seen this cause problems before and it's kinda hard to find. Next check the hubs and make sure they are working. This is where I would start hopefully you are able to find something. Thanks for watching
Thanks for the info i have to identifydB what relay it is the 2010 have 6 on the passenger side in the fuse box thanks again
Delbert Jordan you will need to test each one to see if any of them are not working
Thanks for the helpful tip, having the same issues.
Hopefully you will find this video useful for your fix. Thanks for watching.
So, if the hubs are "stuck" in the locked position, removing the vacuum lines (i.e. causing leak) should release them, correct? What if they stay locked even after doing that?
Str8wirevideo The way I understand it is that the hubs receive a pulse from the vacuum that causes it to engage or dis engage, either way I would look at the hubs if you have checked for leaks in the vacuum system. Hope this helps. Thanks for watching.
Thanks Bob great video. I did the defrost check with no problems, checked relays next to driver battery and they looked good and I could hear them click in when I turned the switch to 4X4, pulled the double vacuum connector at the PHV Solenoid and could hear the vacuum tank drain and the vacuum pump started, put the connector back on and the pump stopped after maybe a minute, also could hear air flow at the vacuum tank when switching to 4 X 4. Any suggestions? FYI I tried to find the PVH price on line with no luck?
It is possible that your hubs could be the problem. You may want to take the hubs apart and look for any rust or corrosion that would keep them from moving. If after you have looked at the hubs and you still want to replace the PHV try eBay. I found one available from Heller Ford: www.ebay.com/sch/hellerfordparts/m.html?_nkw=&_armrs=1&_ipg=&_from=. Search (FORD OEM 1999-2010 FORD F-250,F-350 VACUUM CONTROL SOLENOID 4X4 FRONT HUBS)
funbro1 Thank you, I will borrow a vacumm pump from work today and test each side to the hub and back as you did. If that is good I will start to look into hub repair. FYI I did not hear the PHV engage but did hear air moving
Awesome, good luck and let us know what you find.
funbro1 Using the manual vacuum pump I was able to hold 10" on the Hub lines at both sides but zero back towards the PVH. I could also hold 10" on the individual lines running away from the vacuum tank but test from the 2 hose connections at the tank it was zero. Testing the 2 hose connections from the PVH I had to pump a lot to get to 5" but then it held so I assume this is just due to the vacuum tank volume? Based on this I think I have a leak in the PVH, does that sound right? I was able to find the new OEM PVH for $67 freight included on EBAY. Thanks again. FYI the hubs work smooth manually
Dan Conn Sounds like the PVH might be the problem. $67 is still a small investment compared to taking it in to have it repaired. Thanks for watching
I’ve gotta problem where sometimes the two front wheels will make a noise that almost sounds like bearings. But I’m sure it’s something with the 4wd. Would you have any idea what it might be?
No idea without seeing or hearing it. Sorry.
Great Info! Thank you How To Bob!! You helped me fix my venting / 4x4 engagement issue! One question regarding the 4x4 switch. My used but 'new to me' 07 F350 has no illumination behind the 2wd/4wdHigh/4wdLow curved panel. Wondering if this section is supposed to light up or not when my exterior lights are turned on? If so, can I simply change out a tiny bulb behind the "2x4/4x4" area or do I have to replace the whole square panel (which also include the rear back up sensor button and rear window switch in my case - both of those are illuminated)? Ford part number 5C34-25047A04-H. Thanks for any info or advice you may have!
I don’t remember any illumination on the 4WD switch so I think your good there. Hope this helps, thanks for watching.
What tool did you use to test the vacuum on your lines? My pump is turning on but clearly not getting vaccum
I used a inexpensive vacuum pump. I think Auto Zone has a free rental for them...or at least they used to. Either way you should be able to find a cheap one to get your diagnosis done. Hope this helps, Thanks for watching.
@@funbro1 thx I found a cheap one at harbor freight ill go the route. Thx for the help
Hi Bob. My light for 4x4 is not coming on. Fuses are good. Any ideas?
Could be a solenoid? Could be the light itself? Hard to tell without seeing it.
Thanks for watching.
I have a 2006 F150. When I turned the 4x4 shift knob sometimes it would work if I waited a few minutes but would stay in 4, now the indicator stopped coming on altogether, not working now. Shift motor out or vacuum problem? I need help.. Thanks Mike
There are so many things that this could be. Possibly a slow leak in one of the vacuum lines, the beginning of your PVH going bad, or the hubs could be rusty, dirty, or just sticking. If you live near an Autozone they will loan you a vacuum puller similar to the one in the video. Start by eliminating different parts of the vacuum system and work your way from there to the next possible problem. hope this helps. Check back and let us know how it goes. Thanks
Tried the vent / defrost test with high hopes, I have nothing but defrost in all settings. What does that mean ? "03" with 6.0 manual locks work, but not in cab selector. Lights are on as normal.
Could be a solenoid or a vacuum leak, those are the two things I would check for first. Hope this helps, thanks for watching.
@@funbro1 I took vacuum pump apart and lengthened that super tiny screw, now it works.
Awesome!
Great video I feel like a certified diesel mechanic now lol but really great job
Thanks for watching.
Great Video! It wasn't my PVH but helped me troubleshoot.
Thanks for watching.
On my 2006 F350, the 4x4 cluster light comes on, but I do not have 4x4 when the hubs are in AUTO. One thing I noticed is my air does not change from vent to defrost like it shows in your video. However, the climate control system does change from air to defrost when I use the selector.
Could this be the two relays? Or should I still consider the PVH solenoid. If I lock the hubs manually I do have 4x4, therefore I assume it isn't something at the transfer case. What are your thoughts?
Try removing 1 hose at a time while the PVH is running. Plug up the hole where the hose was removed and see if there is any difference with the PHV. if not go to the next hose and repeat. This may help you track down any leaks you may have. Hope this works for you. Thanks for watching.
Thanks for the quick reply. If I had a leak, wouldn't the vent go to defrost or am I just way off base?
Jim McClure
There is a good chance but that would depend on where the leak is located.
Great video here are my results!! I Hope you can help!! I have the mighty vac same as yours. When I test the lines to the hubs it doesn't hold pressure so I know I need to replace those rubber lines. Then when I hook it up to the system to check back to the air reservoir and turn the key on I hear the pump but again no pressure at all (same thing with the other side) I have a new PVH solenoid, how do you know if the reservoir itself is cracked or bad?
Thank you in advance
Steve
Seattle, WA
It's a 99 Ford F250 super duty
I just had another vacuum leak long after I made this video. Finding leaks can be tricky. What I did was isolate each branch that was coming out of the reservoir by capping off the lines. Once I narrowed down which area kept the pump running I ended up tracing the lines for that branch. I ended up finding a small cut in the gray line and put a coupling on it to seal the leak. I hope this helps. Good luck.
Would your 4x4 still have worked if you had just locked your hubs in manually? Instead of replacing this part?
Yes, I tried it as I needed 4WD at one point and it worked, so this repair is more for convenience. Thanks for watching.
that is the exact same problem i have i just changet the vacuum pump and got air to the vents but now whe i switch to 4x4 it does what your test does i will test it tomorrow thank you for the great info good job how to bob
Hopefully you will find this to be an easy fix. Let us know how it goes. Thanks
Maybe you can give me some pointers I have a 200 F350 SOTF and the hubs don't seem to engage so I have been manually engaging them which is no problem I figure either the sol or I have a leak in the seal in the hubs. What is happning when I shift in to 4 Low some times it goes in but comes right back out but yesterday it shifted in and when I turned it back to 4x4 it stayed in 4 low I switched it several times ( with the brake pedal depressed) and then backed up and shut it off and let it set with the engine runnig and I know this doesent have anything to do with the vaccum because it's a deisl and has a vac pump. What could be going on with the 4x4 and 4 low? I use 4 low to pull my 35 foot camper up our very steep driveway. A buddy of mine told me up unplug something on the passanger firewall to keep the hubs from trying to lock so I would only have rear wheel drive and low range any clues there also? Any help would be appriciated.
Mike
Mike Balloonman Without going step by step through each system on your truck it is very hard to diagnose your issue. Start with the solenoids. Next I would take the hubs apart and check them for operation and leaks. hope this help. Good luck and thanks for watching.
funbro1 Actually my question is on help with the transfer case hanging in 4 low and then coming out on it's own sometimes but Tuesday it wouldn't come out of 4 low when you turn the switch back to 4x4 the transfer case shifter is electric is it not?
My 2004 F-150 4 High works but not my Low, any ideas please ? Great video
***** Check the relays under the hood they should be the same so you can switch them out to do a little test, also check the fuses, both under the hood and under the dash. Hope this helps. Thanks for watching.
How do you close off the vacuum line for Warn 4x4 manual lock hub post-install?
***** You could probably use some type of plug as long as it seals the vacuum off good.
What year tuck is that and which locking hubs are those?
2007, stock.
Thanks for watching.
I seem to have an issue of he hub lock solenoid having a constant 12v applied to it no matter where my switch position is. The solenoid works (manually applied 12v to it) the shift selector on the dash appears to work, as the lights come on for 2wd, 4wd and 4-lo. I her the transfer case lock in and out when moving to 4, but I never have the solenoid power shifted to product the vacuum. Any suggestions? Since it appears to be getting power, fuses don't appear to be the issue. I'm not seeing an issue of concern with the ventilation switching. Potential relay issue?
It sounds like you checked everything but the relay. I would probably look in that direction.
Looks like my relays are good. Do you know if the PVH should always have the +12 on it, or only when activated by the switch? Mine is always hot, no matter the swtich position.
The PVH will have 12v going to it when it needs to turn on. If there is no vacuum it will cause the PVH to call for voltage. try taking out the hoses one by one and plug up the holes and see if anything changes. It may take a little tiime of the vacuum generator running to create enough vacuum to tell it to kick off so be patient. This might help eliminate a possible leak. hope this works for you.
Thanks - I'll give that a shot. I can hear the solenoid activate when I plug it, in plug it, so it's always getting +12. I've confirmed this when UNPLUGGING the PVH and using a multimeter, it always has +12. The pump does not always run either, but WILL run if I unplug the air lines from the PVH. I'll go thru the vac hoses again and see what I come up with.
Were you able to fix this? I'm having the same problem?
I have a 2003 F150. My vent works, but I can't get heat out of the floor. Weather my 4x4 is on or off, I can get vent, and def, but no floor. My 4x4 light comes on, but no 4x4. When I go to 4l, I can hear the transfer case shift, but still no wheel action. Is this still a vacuum issue? and do I still look in the same places?.
+Eric G It sounds like it may still be a vacuum problem. You can trace all the vacuum lines back from the vacuum pump by unplugging them one at a time and putting your finger over the hole. If the pump stops you have found your leak.Plug the hose back in. From there follow that hose to another point that can be disconnected and repeat the process till you find the source of the leak. It can be hard to trace the hoses and time consuming. I have traced a leak back to the switching unit on the dash(The one that switches from floor to vent to defrost). I'm not 100% sure if a vacuum leak is the problem with the 4x4 but it does sounds like you still have a leak somewhere. Hope this helps, Good luck.
It helps a little bit. I do not have a vacuum pump that I can find. I did test vacuum on the 4x4 cylanods and have great pressures when and where I should. I was able to get underneath the truck today and the actuator is moving back and forth just find. How ever, there is a vacuum line that goes into the housing above the actuator, and do not have vacuum on it in either 2 or 4 mode. I will have to get underneath it when I have dry ground after I find out when I should have vacuum on that line. I am hoping that is the answer.
f150 has no vac pump.....diesel needs one because diesels do not make vacuum like a gas engine does.