Brake booster checks, operation and push rod adjustment
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- Опубликовано: 7 сен 2024
- This video covers a number of aspects related to the testing and operation of a brake 'booster' otherwise known as a brake servo.
Firstly, we test the one-way valve in the vacuum supply pipe. Then I show you how to complete a simple on-car test to see if the brake booster is working correctly.
The theory on how a a brake booster increases the braking force is covered and finally I show you how to take measurements to check that the brake booster to master cylinder push-rod length is within specification.
If not then I show you how to make the necessary adjustments needed.
As you will see in the video, the importance of this push-rod adjustment is often overlooked by individuals. Whether you are replacing the brake booster or the master cylinder, having the correct clearance between the end of the push rod and the primary piston in the master cylinder is critical. If incorrect can cause issues relating to binding brakes and difficulty to bleed up the system.
Any questions please add them to the comments section below...
Andy Mechanic!
Very long video, most people today can’t watch something past 10 minutes, but what a fantastic and very thorough explanation!
Way worth the time, a must watch! Thank you for posting this.
Thanks :-)
Play speed to 1.25 and it's much easier to maintain focus. :))
Thank you Mr. Young! I am 64 years old and have never known about adjusting the booster rod.
I truly envy your students!
Only 8 minutes in and I have learned so much more that I didn't see in tons of other car repair videos I watched in RUclips!!
One of the only videos that actually discusses booster adjustable rod length (booster to master cylinder). Very thorough. Thank you from Texas. :)
+Rod McAfee Cheers Rod, really appreciate the feedback and happy to know the info is of help. Drive safe. Cheers Andy
This is exactally what I have been needing in my life! I know the parts, I know how to replace them. I just need to know how to test the components, to be sure I am not wasting time and money replacing the wrong parts! Thank you for the hard work to post these videos. They have just made my life a little easier, and a little better! THANK YO I
I just received a Dorman master and Cardone booster for my 97 Wrangler. I bought both through Amazon which had indicated that they would fit. Was very nervous about installing both without knowing what the relationship was between the push rod and plunger. Using this amazing video, I found that there is a 0.0115" (0.292mm) clearance between the two. I triple checked all of my measurements and calculations assuming there was no way it would be this spot on between two different manufacturers. Now when I finally do the installation, I will know for a fact they fit. Without this video, I would always be suspicious of the installation. Thanks Andy!!!!
Good Morning Charles, no problem at all. It's a clearance that is often overlooked, even by some Mechanics unfortunately. However, going by just how popular this video has turned out, a few more people are aware of it and the symptoms if there is no, or worse still, a negative clearance!
Many thanks for the feedback & Good Luck with the install :-)
Cheers Andy
Thank you for this video. Two months ago had master cylinder replaced. Since then the brakes would drag and on ocassions lock up. Pedal was always hard after a few minutes of driving. Had car towed two weeks ago because brakes were locked and wouldnt move. Two mechanic shops later and being told I needed a new abs module I came across this video. Ran this by the mechanic and he dismissed it. Picked the car up and adjusted it myself and now have a normal brake pedal, no drag and car cruises at much lower rpms.
That's great news Tim, pleased the video has helped you & just proves if you want a job doing right then do it yourself!
Cheers for now Andy
Many thanks Andy, I now understand something I previously had absolutely no knowledge of.
My brakes were dragging and locking after driving around and I had replaced all calipers and lines . i just went out and was able to crawl under the dash and adjust the pedal distance from booster rod and it looks like i have fixed the problem the pedal was real high and the valve you talked about may have not had enough space once fluid expanded. thanks👍
m8 what a great instructor you are! Your students should feel very lucky to have you teaching them
I know this is an old video, but I can not thank you enough!!! I chased a front brake issue on a 1994 Dodge Dakota for months, first replacing all the "usual suspects" (rotors, pads, calipers, and brake hoses) and was pulling my hair out until I found your video and one other, both recommending this often-overlooked possibility. Turns out the booster shaft was about 1/8" too far forward, keeping just enough pressure on the front brakes to make them drag. Made the adjustment and fixed the issue. Thanks again!!!
61.16⁴😂
61.16⁴
Thank You Andy. What an excellent tutor you are. As a design-engineer (now retired) from the marine industry and otherwise a lifelong (now classic-bike) motorcyclist I knew nothing about servos but what I'd deciphered from a workshop manual. Your explanation, together with practical demonstration was both enlightening and just what I needed as a confidence booster (pun unintended) to tackle my 1968's Daimler 250's (same as Mk2 Jaguar) servo. That happens to be a remote unit, but your tutorial is a foundation which I can readapt my car's specifics. i wish I were over there to buy you a beer or two. Cheers, Pete
Thanks Pete, it's great to know you found the video helpful. Good Luck on your Quest. All the best. Andy
Test it before you fit it. New doesn't mean good, new means unused. Thank you for sharing and stay safe.
never knew how brake booster actually works till i watched ur video, thanx alot!!!! great video.
Andy your videos are fantastic. One of the best at explaining the mechanics and how components work with each other. Everything is brought down to a level of a mechanic and not an engineer. Being a mechanic I just enjoy your channel. Keep them coming.
Very passionate and knowledgeable instruction. Hopefully your students recognize the opportunity. Really enjoyed all 50 minutes. There is so much bad and wrong information about this topic on the forums, its great to see such a detailed breakdown. Everyone working on brakes needs to watch and understand this. Thanks for putting it out to the world.
Just replaced master cylinder on 1978 Ford E-150 and had the exact problem you described at the beginning: brakes grabbing suddenly and hard. Now I know how to proceed with solution. Thanks, mate.
This is the best video I have ever seen on brake booster. It was a very informative video. Great job.
Greetings from Pensacola Florida.
50 years I've worked on my own cars and never suspected the pushrod needing adjustment. Thanks for the info. Very needed. I replaced a master cylinder on my F150 recently and didn't adjust it. Now I will do the job again which is normal for me. Not that I like it. This makes sense when the remanned master cylinder has been cleaned up on the mating surface and material removed thereby lessening the clearance. 1mm seems like the likely amount removed on a machine.
Your videos are very informative, thank you. I've been working on my own vehicles since high school which is now over 40 years and I never knew how critical the brake booster push rod adjustment was. You're an excellent teacher in your videos and the 50 minutes on this video was interesting the entire time. Thank you again from Idaho, USA.
+jake102308 thanks Jake. Sorry I couldn't reply earlier. I am out on a road trip around the North Island of New Zealand visiting Yamaha motorcycle dealers this week.
Thanks for the feedback. Pleased you enjoyed the video.
Cheers for now Andy
Great detail explanation of the brake booster operations. It was very helpful to the replacement of the booster on my car. I learn a lot of things that I wouldn't have known before. Thank you for making this video.
Thank you for all the info you gave me a lot more to think about and how important it is to get the adjustment fight, all the other videos just show you how to replace the unit without giving importan information about it which I can do myselt but would not know how to do the fine adjustment. THANK YOU
Andy, thank you for this video!! After multiple visits to my mechanic and $$ later I made the measurements myself and found that the push rod was 7.5mm too short and hence the delayed and soft pedal. Mechanic made several excuses that the rod should never be adjusted and then said he did make an adjustment but only a little bit. The one culprit with my car (300M) is there is a purge canister mounting bracket between the MC and BB which of course increases the distance between the BB rod and the MC piston. While this still didn't make up the entire distance it just proves that when either of these components are replaced, interference measurements MUST be made! Not sure that remanufacturing shops set to a standard or the FSM but my FSM doesn't mention the set distance so I'm guessing they just set a standard distance. Great videos and definitely subbed! Cheers!🍻
Thanks Steve, it's amazing how many Mechanics aren't aware of this critical adjustment! Back to college I say!
Great to hear the info in the video helped you out & improved the safety of your vehicle. Thanks for the feedback. Cheers Andy
Awesome video...just purchased master & booster cylinders to replace on my 1974 Chevy Nova just because they are the orginals. Definitely will measure clearance. Working on Bronco that has touchy brakes when applied that your video will allow me to fix after many attempts. Thank You Mate😊
Yazmin
Venice Beach CA
🏂🏁🏂🏁🏂🏁
Thanks you for this video. This has to be the best video on brake boosters and push rod adjustment that I have seen. Now even I understand how the system works. This explains why three repair shops say they can't explain why after changing out the master cylinder and the booster, my brake pedal goes way down towards the floor before the brakes engage. I bet that they did not do the meticulous measurements to readjust the push rod distance. especially since both the master cylinder and the booster are new and not OEM. Now I have to find a specialty brake shop where I live or send my car to New Zealand to be repaired.
This is the second time in my life I've had a rod length issue. The first one was of a personal nature so you wouldn't have been much help, however, your video pinpointed that this time my rod was too long by .020 inches (.060 mm for you
Wow! thanks for the great explanation. I may now have a clue about my check engine light and pulsating brake pedal at standing stop.
Very Good Andy. Thanks for posting this video. I had no idea i had to even think about the measurements you mention closer to the end of this video.
Thanks Andy I am having problems with my brakes locking on and it looks like from your video that it could be push rod adjustment as one of the symptoms is that it only starts to happen after a good distance after things heat up not when cold. Truly well done video clear and easy to listen to, thanks again
Hi Allan, yes, certainly sounds like it's a pushrod length issue.
Good luck :-)
Cheers Andy
Brilliant, cheers from NJ USA! I have a 66 Chevelle with a 383 in it, i am going to replace its Mechanical brakes to assisted and front disc brakes from drum. I've researched booster and mastercylinder, with proportioning valve packages quite a lot. Ebay has some of these at reasonable prices but comments are sketchy at best. Ranging from No peddle to no stopping power after the install. I wouldn't be surprised if problems were from that push rod, not being adjusted properly, which has kept me from getting one of them. My 383 only makes about 8-10 inches of vacuum so, i'm researching auxiliary vac pumps as well. But your excellent video has been a helping of food for thought Andy. Thank you!!
Thanks for an amazing video, I was tearing my hair our wondering why my brakes on my 1971 VW T2 Bus were binding and locking on after having a brake servo system upgrade fitted by a classic VW camper specialist. They obviously didn't bother to check the push rod clearance. I wonder why they call themselves specialists 🙄
No problem Sir, nice vehicle :-)
Happy to be of help.
All the best. Andy
Andy, absolutely the best video / instruction I've ever seen. It now makes total sense relating to some elements of understanding I was missing. The additional attention to detail is super helpful and likely explains why I occasionally encountered very odd brake issues at times and certainly I will be applying the correct methods you explained. Thank you very much; and I believe you just helped me isolate / solve a 10+ year old issue on my 89 Toy 4x4 . Kudos!
Andy great video I've a new Avenue to try to get stronger brake pedal pressure, you are absolutely right where you mentioned changing master cylinder and hydro boost and not adjusting brake push rod, I've gone as far as gravity bleeding brake, little result but not the way I know my brakes should feel, thanks for putting this video out there. ..
Best explanation I've found on RUclips. Thank you. I really understand why my Wilwood brakes are locking up.
Great vid. Ty for teaching this old school diyer a new truck! Awesome tutorial on something I've to tackle very soon. I was hearing a high pitched squeal, now it's a hissing/suctioning sound and to stop I've to push much harder! I'd already guessed it was the brake booster or servo. But I'd no idea how to adjust the actuator rod ty again and God Bless you for diseminating really great info!!!!
Supreme information! Explained perfectly...
Thank you very much Andy..I'm just doing my apprentice and found most of your videos are really helpful..This one is the best one..Thanks thanks alot..❤❤🙏🙏
No problem at all....I'm pleased you find them helpful.
Thanks for the feedback. Cheers Andy
Great video! I installed a new brake booster and master cylinder without adjusting the rod at first... lol
thank you for sharing this valuable advice ..just spent 6 weeks on and off about 8 full days completely replacing the full brake system on a 1984 escort..having bled the system twenty times even with pressure bleeder still have full brakes but low down the pedal travel...having ignored this adjuster thinking it was factory set I now am going to do this adjustment to see if I get pedal back...
NEW discs new pads new shoes new drums new rear cylinders new master cylinder new braided hoses ..servo working ...5 litres fluid..pressure bleed kit...
if only I knew about this adjuster...
I will let you know the progress
thanks again...
Thank you Andy. I am changing my power brake booster soon. I assumed the setting was factory set, however since I am not buying a new prefited master cylinder already attatched, I will make sure I check the spacing. Thank you for such an informative and complete video.
Thanks so much for this great video. Did not realize you needed to adjust the booster upon replacement of master cyl. Having the front brake lockup issue and trouble bleeding. Going to try this, pretty confident this is the issue. again, nice work!
+Welesly77 Hey, no problem. Yes, seems like you have a class is case if 'negative' clearance there. Just shorten down the push rod a little and that should fix it. If you don't have the specs then just do a measure up and give it between 0.3 & 0.5mm that should work :-)
A Very informative video sir with alot of knowledge, you got yourself a new student all the way from bahrain!
ill be watching all your videos and learning.
Thank you so much for sharing your knowledge with us. :)
I also congratulate you for this video.Thank you so much for sharing your knowledge. DIY from New Jersey, USA
Just excellent. The detailed technical explanation is very helpful!
Thank you for this informative video. I fought a Subaru Legacy with soft brakes for a long time , thought that was just how they would be. Replaced master cylinder..No help. Turns out that the booster piston was not extended far enough for the master cylinder that was installed. My daughter sends thanks , as the pedal is now how it always should have been.
Cheers Tom, I'm pleased to know the info in the video has helped sort out the brake issue. This is an adjustment that is often unknown & overlooked when replacing one or both of the components.
Drive safe. Andy
I had wondered how it worked when my car stopped working. Great video mate!
Thanks Andy ! Just put a brand new master and booster on my 71 cutlass
And pedal hard as a rock ! I figured maybe the hot cam was doing it but at 15 inches it should have at least 1 good stop! Or some assist and low and behold when you said afr will go up if the booster is leaking ..
That’s exactly what mine was doing I would watch it go from 12.8 to 17.0 16.0 etc ....great vid! Just goes to show just because something is new doesn’t mean it’s good! Ugh!!
Thank you very much for sharing. Nobody does this stuff. They just slam it in. Thanks from the Netherlands.
Brilliantly done. Exactly what I've been looking for. Thank you.
I went down the road last week and when I stepped on the brakes, there was a loud bang and the brake pedal went to the floor. When the car is running, the brake pedal pushes easily but the brakes only work as manual brakes, and you have to push it down all the way and push hard. It's like the rod from the booster broke off and doesn't reach the master cylinder. There are no leaks, and the booster is holding vacuum. Only thing I can think of is that adjuster has broken off. Thanks for this video and it looks like you solved my problem.
Thank you for making this extremely detailed and helpful video!
A very informative and through explanation. The last mechanic working on my brakes was supposed to be ASE certified; he didn't know his ass from first base.
Bobs your uncle, mate. That was one of the most entertaining and informative videos I’ve seen in awhile. The yank from across the pond
Nice meeting you andy your tutorial is very informative thanks your time to share your knowledge 🤝🤝🤝
Wow... Such a good video! Thank you for making this!
Thanks Ive been looking for someone who explains how to adjust that rod & measure etc as I have to install a whole new setup in my 1965 pontiac
Thank you Andy, you may have just solved my problem. after replacing master cylinder and brake booster my front brakes keep locking up. I"ll have this checked out very soon. But this makes a whole bunch of sense. Thanks again.
Very nice job with the video! Well spoken and easy to understand, thank you
Thanks. I do try to explain things in an easy to understand way & appreciate your feedback. Pleased you found the video helpful.
Cheers Andy
Subbed!!! This was the best automotive video I've ever seen!!! Thank you sir.
+T3X4S B0Y Cheers & welcome aboard :-)
Wow this was so acurate. On my current build My brakes kept dragging and i couldnt figure out why. Sure enough it was that adjustable rod. Just saved my ass from buying a new booster. Awesome video 👏🏻
Thank you so much for the details. I had no idea that he one way valve can be inside the vacuum hose.
Seems like my 2001 Hyundai Accent 1.6L maybe having a problem with that hose.
I have been getting vacuum leak codes and have checked all over for one and have not been able to detect it.
I just replaced the booster today, it had no check / one way valve on it as it is a one piece unit, so I decided to go ahead and replace it. These codes maybe coming back if the problem was inside the hose.
So much to learn.
No problem. Yes, those valves can be hidden in the vacuum supply hose. Sometimes with no obvious external indication that they are there. However, there must be a non return valve in the system somewhere to maintain vacuum should the engine stall - to continue to provide brake assistance.
Cheers Andy
Thank you. I think that you’ve identified and explained my problem - all new brakes, master cylinder but no push rod adjustment. And we couldn’t work out why - opposite to this video, I believe that my push rod is too far in.
difficult to believe it's not adjustable? instead of the rod end protruding out towards the master, look on the linkage end where it connects to the brake pedal, you may find a knurled not there that can be loosened and the the rod can be twisted to lengthen or shorten, at least that's how it works on my old Acura
James Ray I’m learning!! Yes, it is adjustable, but unlike this video, it did not protrude beyond the surface of the booster. In order to get it to do so, after we made our calculations, all we needed to do was have someone depress the brake pedal for the rod to come out enough to be adjusted.
I just found your videos and this one was the most helpful I have found yet in diagnosing my brake issues. Thank you! My son loves cars and I am subscribing so he can learn from you.
Excellent! Very thorough and well explained.
I wish I had watched this a long time ago. I've had a problem with my brakes heating up and just figured out the pushrod was too long on the inside of the car. I adjusted it and they work perfect. I guess the pedal was letting in just a bit of atmospheric pressure and pushing on the master cylinder. Good job on the lesson.
+beastybmiked sounds like you found the fault. Yes, both input and output push rods should have a small amount of free play. Cheers Andy
Thanks so much for this video Andy as you have solved my low pedal issue after years of driving my 47 GMC modified by who knows who ? with a Trans Am frame and a rebuilt Corvette 350 with modified front Discs and rear Drums. Thanks again!
+Ralph Feldes No problem Ralph. If I was there you could take me for a test drive. Sounds a great car :-)
Very good explanation, had the details I was searching for, Thank you from Tijuana
Some boosters are easier to check rod adjustment where the rod is set deep inside the booster rather than protruding and the spec can be checked by measuring the distance from the tip of the rod to the flat plain of the booster outer face.....
Hi Sam, thanks for your question....I had exactly the same problem with an old Nissan Patrol a few years ago. It turned out to be a fault with the rubber brake flexi pipe attached to the caliper. Inside the rubber had perished so badly that a flap of rubber was blocking the pipe. Pressurized fluid could push the flap open & enter the caliper but it was unable to return back to the reservoir therefore preventing piston retraction. To check for this just open the bleed nipple, if the piston retracts & the disc rotates freely then its likely you'll need a new brake flexi pipe. If the piston still doesn't retract then I'd guess the piston is binding due to corrosion or been out of round - you'll have to strip the caliper to check this properly. Also check the piston hasn't gone out of round, this can cause it to jam in the caliper body too.
Let me know how you get on, if its neither of these problems then I'll have a bit more of a think....okay?
Oky i wil let je now . I on my job side now wen i turn home after 14 day
You can also simply turn your wheel all the way each way a few times slowly and see if it releases
Excellent teacher. Thanks Andy.
Awesome video with great explanations. Glad I found this.
Thank you, learned a lot! From Sacramento California
Hello I Just found you! Great video. I learned this the hard way when I changed out a MC and did not check the length. Spent a great deal of time wasted till it hit me to check. In the past I was just lucky things worked out. I’d love to see a video on the proportioning valve on a 1978 Ford F-150. Drums rear, and disc front. Thanks!
I've been hearing an hiss from around the break booster, I thought it was the diaphragm or something, may be it's the valve coming out of it. very good vid.
more likely a vacuum hose leak or the check valve isn't tight in the hose?
The adustment problem you were talking about happened to my mate's land rover. He'd fitted a new master cylinder and put the adjuster nut back where it was before, however obviously being a new unit it was less play in it so it must have shut off this valve and caused the brakes to start binding after 10-15 mins run. We'd spent ages looking at it until I relalised he's probably not left some slack for the expansion. All was well after taking back the nut a turn or two.
Also had a similar problem with a Citroen in a garage I used to work in, after swapping pads, discs, calipers, shoes it turned out the brake fluid was so old it was boiling when the heat got to it, change of fluid sorted the brakes binding up.
+Andrew Mi Thanks for the feedback Andrew, it's a common problem having incorrect pushrod length. Even some Mechanics are unaware that re-adjustment needs to be done whenever either the booster or master cylinder is changed. Thanks for the info and welcome to my RUclips channel :-)
Yes it is an intersting point that not many people are aware of Andy. THanks for the welcome as well! Will keep my eye out for more of your stuff.
Great video, always wanted to know more about brakes. Thanks!
Thanks Andy!!!! Hope your New Year (now 2024 !!) is pretty Stoked Mate!
Thanks, pretty good so far! :-)
Thanks for posting great video, helps me understand booster system. My problem is intermittent drop of brake pedal, happens very infrequently, other times all works well and brake holds pressure even after extended application of foot pressure. Brake shop said it could be vacuum related, they did not believe it was MC, but I don't see how it could be vacuum related. Car is 1990 Volvo 240. Thanks, Jack
My bet it's one of the main seals in the master cylinder allowing fluid bypass.
Suggest either a rebuild and new seal kit or replace unit.
Let me know how you get on please
Cheers
Andy
Thanks and the best!! I own BA falcon and AU falcon. I have been having issues with hand break adjustments on my AU for a long time hoping to see a informative video from you. And then my BA suffers from only driver side front break issue where it feels dragging on the road. After changing pads callipers no help. Suspect it's break booster rod for sure. Thanks again.
Andy topvideo. i learn a lot from you. greetz jan from the Netherlands
Excellent video, great explanation Andy! I'm converting from manual to power brakes on my '65 Chevy Impala and this is incredibly helpful showing in detail how to measure and adjust the pushrod-to-piston clearance. A big thank you from California!
Clear and complete presentation!
Great video. Very informative.
I should probably remove the booster on my car. After watching this video I may have not adjusted the rod correctly.
At cruising speed I cannot achieve a sudden stop or a quick stop if I needed to. Pretty scary knowing there's a possibility you might slam into rear of car in front of you if they suddenly braked hard. This video is very well explained Andy.
That was a Great Video. Thank you for making the video. I learned a lot and will have to try in on my car.
I am in my 50s and have been working on cars since i was about 11 or so, i learned something this weekend regarding boosters that i did not know,a booster can hold vacuum perfectly and still not work, i was hesitant to change mine since it held vacuum and it had some assist but once the final step came in to stop the car it was like hitting a wall, really had to lay on it.
I was always under the impression that no vacuum=no assist,well this thing was holding plenty of it, you would release the valve and it you could hear it loud and clear but for some reason it wasn't working,the new booster has too much assist, ha ha ha but I'm happy as i can be,car stops now really nice, I'm gonna dismantle that old booster here soon, I'm really curious to see whats wrong with it.
When i installed my new booster i bought the tool to check rod clearance etc or how close it should be and all that, i got it down as close as i could, seems to be working fine,pedal does have quite a bit of travel but i think since i also installed a master cylinder i need to rebleed everything and will be doing that this weekend but again, compared to what it was i like my brakes a lot better now!
Thank you for this important info!
I’m really sorry to be bothering you with all of this (and thankful that you’re one of the few youtubers that actually answer). I had a new brake system put on my car, with everything new, other than the brake booster. My brakes engage when the pedal is practically on the floor. My mechanic did NOT adjust for the push rod, etc. I have my old brake system, and am trying to ‘practice’ doing this, following your video. What I do notice is that my original MC did not go all the way into the brake booster. There is an o-ring halfway down on the MC shaft, and that is what ‘mates’ with the brake booster surface. (I do not know if this MC was original to the car, by the way). The wear on the screws on the brake booster show that the MC had only been screwed down halfway, when it was installed, with the o-ring mating to the brake booster surface. I suppose this is somewhat meaningless to adjusting my new MC to the existing brake booster, but wondered if you had ever seen a set up like this. In researching, I see that there are tools that you can buy that do the adjustment (so we don’t have to do the math), but those tools would go to what you are indicating as the mating surface for the MC, rather than the o-ring set up that I see on my original MC. I’m getting all confused. My MC measurement to the pin is 42mm and measurement to the mating surface (o-ring) is 18mm, which indicates 24mm. My booster (the pin does NOT protrude, but is inside the hole) is 20.5mm. The brakes worked great this way. I don’t get it....:(
Excellent tutorial. I'm guessing it would be easier to make the push rod adjustments with the brake booster out of the engine compartment? Many, many thanks from British Columbia, Canada for taking the time and effort to teach us.
Hi Andy,
Well done, very clear & professionnel demonstration
Will test it.
Thanks
Is it possible for the vacuum valve to act differently in colder weather as opposed to summer weather?
Hmmm....not thar I'm aware of, never come across a difference though changes in atmospheric pressure will vary (very slightly) the assistance provided by the booster but I doubt it would be noticeable.
Cheers
Andy
You forgot to bench test the booster. I like your video a lot thank you very much
I needed this! you are very thorough, and I like that, thanks... new subscriber here
Oh my goodness...so this is why my Rav4 2007 keeps raving high whenever I push the brakes? Even when the vehicle is running the brake pedal gets hard most times and soft few times, intermittent just like that. I have really spent a whole lot on quack mechanics trying to fix this. I will fix this myself. Thanks for the knowledge!
Thanks for your very thorough video.
Thanks :-)
I found this video 100% useful ! Thumbs up ! Subscribed ! Thanks for sharing your knowledge on RUclips !
thank you very much had this problem for many years now
Sorry for the late reply Wade, that's great news, I'm really please this video has helped you get your car sorted. Yes, this is an issue that is very often overlooked by many mechanics and can cause some serious problems too.
Cheers
Andy
Excellent video Andy, very informative. Fixing to replace the Master Cylinder on my 1990 Ford F-150 because I see a small amount of brake fluid between the Master and the Booster, the pedal won't pump up and it goes to the floor even after being bled. Now I know how to adjust the rod...many thanks!
thanks for your knowledge that you share here, very helpful watched did whole video and did not even realize hw long it was until the end, very well put together..
Great and informative video Andy. I look forward to reviewing your other videos. Nice refresher courses, lol. Anyway. I live in the US. in the northeastern area. A lot of corrosion and rust. A big problem that I see constantly here is when people are changing brake pads, They do not clean and lube the slides and pins, Therefore creating a braking issue. I can not tell you how often I have to use the torches to remove and replace frozen Caliper pins and boots. That would be a great video if you have not done so already, How to properly do a brake job.
Wish I would have watched this sooner. I just ran into overheating brakes and couldn't for the life of me figure out what the cause was so like a smart ass I started swapping parts instead of going from point A to point B in a diagnostic. By now I have swapped out EVERYTHING related to the braking system/issue and it turns out it was that piston/pushrod that wasn't adjusted properly....
Thank you. Learned so much from you right now. Just did a master cylinder and booster swap and never adjusted anything and been having trouble with a mushy pedal. Did the bleeding twice already but now going to adjust the pushrod like you showed on the video and hopefully that was my issue. Either way awesome video and clear information. Glad I found your channel and going to check out your other videos.
Did this end up being your problem? I just replaced my master cylinder and am experiencing a very spongy pedal that goes to the floor when the engine is running. Have bleed all the brakes and abs unit multiple times. No fluid leak. Problem went away when I unhooked the vacuum hose. Wondering if the pushrod is too short for the aftermarket master cylinder.