It is always amazing when some one such as this goes out of there way to help and assist others. Well done and thank you. But I do need to point out an obvious step that was missed. The original damaged impeller was missing sections of blades! These are now floating around somewhere in the cooling system! These need to be found and removed or water flow may very well be restricted causing further over heating and damage.
that sensor behind the harmonic balancer is the crankshaft position sensor. Fantastic video, really good camera work and lighting, easy to follow. With the shortage of marine mechanics nationwide these videos are the only things helping owners of older boats to keep them going!
Local dealer wanted to charge over $400 to just change the impeller. 2005 Chaparral 204 ssi. Took about 3 hours total. Can't thank you enough for this video!!!
It's easier to leave that bracket on the impeller housing and take it off after you get the pump out. You can also leave that pulley on the bracket. Also, an easy way to get the impeller into the housing is to use a hose clamp. Get the fins going in the same direction and tighten the clamp. Then just set the impeller in the pump housing and push it through the clamp.
Hello Sir, your video was a major help to me figuring out how to change the impeller on my 2005 496 MAG's... The Gen 3 fuel setup, pullies, etc... are all the same on mine. Greatly appreciated!
I know you made this video quite a few years ago, but thanks for taking the time to do it!! I picked up a 290 Amberjack last fall, and want to replace the impellers on both engines so i know they are good. This video really helped me prepare for how to tackle this job.
I have a 2007 Larson LXI 268. I sure wish I had the room you have to work. Heck I cant even see the pump and can hardly touch it. Great video, I might just let the dealer do this one for me....
this is the same water pump as mine....I was checking to see if the impeller is off set in the housing. I thought mine was out of wack...all good. Thank you for your video, I can put mine back on after I clean up my pump and bracket.
Raymond Pomaville It's basically the same setup. Same pump housing and hose connections on the rear. The alternator will be on the other side of motor and the cooling water hoses that are around the pump will not be in the way like it is on the 5.0.
You were so right about those back bolts on the gen 3 cool fuel module! They were a bear to get loosened. Thank you for confirming about the worthless tab on the mounting bracket. Next time it will take half the time to complete the job.
Hi. I used your video while doing the work - watching it on my phone. Thanks a bunch - very helpful. I don't have the Gen 3 fuel filter, but still had to remove the pump to get at the impeller. Now, to put it back on.
Thanks for the video. My pump failed and the mechanic at my marina refused the work due to lack of access. My boat only has about 6" between the motor and mid cabin bulkhead. (Rinker 250) Thanks to your video I knew what had to be done and was able to angle a mirror to see all the brackets and hoses and successfully remove the pump. I know the video was a pain to make and edit, but it just might have saved my season! I really owe you one pal, thanks again. Dennis
It's called the water distribution housing. On my boat, it's how I drain water / RV antifreeze from the motor. After you flush out your motor with RV antifreeze, it's probably a good idea to remove the blue plugs to drain everything.
they changed to a plastic housing which looks easier to maintain. There are also Hardin stainless steel versions of these people recommend and also ditching the unit completely and going to a crankshaft powered version (smaller belt needed)
Thanks! I have the same engines in my '08 Sea Ray Sundancer. Doesnt look like a bad job. I'm going to make a little platform board like you have to help me kneel down. Mine's kind of tight in there with a genset in front of the engines.
Yeah, where Mercrusier put the raw water pump can be a nightmare. Most Volvo’s, Crusaders and Marine Power’s only take a few minutes. Change the impeller at least every two years from the time of the install regardless of storage or running hours. If you went too long you may have lots of problems. If you have an oil cooler, much of the impeller debris may be bunched up there. Other places are fuel cooling, small cylinder head passageways and heat exchanger on close systems. Hopefully it went through and out. To lube the impeller, never use petroleum based products, silicone grease is best. Some have used vegetable oil and dish soap, but I can’t judge those.
Good video describing the job on that specific engine. I have the 496 and did the job and it was a bit harder than your procedure. What were they thinking, putting a part that needs regular servicing in the worst possible location! I'm looking to replace with a crank mounted water pump conversion, but after a lot of searching, it looks like it can't be done on the 496, for whatever reason.
Danny Troy I also have the 496 mags, two of them! I wonder if you could give me a few pointers. I'm sure I can replace the impeller and the o ring. But, how in the hell do you get the damn pump out? Any place online I can find information? Darn, I hate to pay somebody to do this... Oh, by the way, can this be done in the water? I thought I could pinch the hoses with a couple of thin boards and clamps, but there isn't much room. Maybe stuff some rags in the hoses?RickTucson, AZ
azcharlie2009 If you need to print out the instructions, this is what I found on a site. Thanks to the original poster. Sorry, I no longer remember who posted it, or where the site was. Also, the video pretty much shows the total procedure. If you can't remove it, is it because the two hoses are still connected? They are the hardest part to deal with, in my opinion. Anyway, here's the procedure: o 1 Close the seacock. This through-hull valve allows seawater to come into the pump. o 2 Note the amount of free play in the serpentine belt that drives the pump. Loosen the bolt at the top of the alternator that acts as a hinge. Loosen the alternator adjustment nut with a 19-mm socket and back the adjustment bolt out approximately 1 inch. Swing the alternator inward, slacking tension on the belt. Swing the alternator toward the engine as far as possible and slide the belt from one of the non-grooved pulleys. Remove the belt and set it aside without turning it over -- it must be reinstalled in the same orientation as it was in when you removed it. o 3 Remove the two 19-mm nuts that hold the water pump and the 20-mm bolt holding the pulley bracket and two pulleys, with sockets of the appropriate sizes. Remove the bracket and pulleys and set them aside. Remove the two blue, plastic wing-bolt plugs from behind the pump's port side, keeping track of the O-rings. Remove the hose clamps from both the outgoing, bottom hose and the red incoming pump vacuum hose on top of the pump with a screwdriver. Lift the tab that extends the length of the sensor housing to open the housing and gain access to the wiring inside. Remove the wiring harness that runs to the back of the pump. Insert a large, flat-blade screwdriver between the pump's left side and the engine block and work the pump free. o 4 Remove the six 10-mm nuts from the back of the pump with a 10-mm socket and separate the two halves of the pump housing. Lay the pump face down on the pulley and pull the back half free. Note that the impeller turns counterclockwise, since you are viewing it from "the bottom." Make a small mark on the side of the impeller facing you with an indelible pen, so you may return the same face to the pump. Remove the impeller, using two small pry bars to lever it if necessary. o 5 Inspect the impeller and the interior of the pump housing for damage or wear. Replace the pump housing if it exhibits excessive signs of wear, from the contents of the pump replacement kit. Replace the impeller if it shows wear or has broken blades. Lubricate the outer edges of the propeller vanes and the impeller shaft with white marine grease, if you replace the impeller. Locate the "Direction of Rotation" arrow inside the pump. As you install the impeller onto the pump, turn the pulley so the impeller turns in the direction indicated by the arrow, while you push down on the impeller to seat it. o 6 Rub a dab of white marine grease around the edge of the pump, where you installed the impeller. Place the new O-ring from the pump kit around the pump's edge. Put marine gasket sealer on the threads of the bolts that hold the two halves of the pump together. Thread the six 10-mm bolts back into place and tighten them securely. Thread the two 19-mm bolts through the pulley bracket and into the water pump, tightening each securely. Bolt the pulley bracket back into place with the single 20-mm bolt and tighten the bolt until it is snug. Replace the hose clamps and connect the hoses, tightening the hose clamps fully with a screwdriver. Reconnect the sensor wiring harness to the pump, then into the sensor housing. Close the housing and press the locking tab. o 7 Replace and tighten the blue-plastic wing-nut plugs and their O-rings. Slide the serpentine belt over a smooth pulley in the same orientation in which it was removed. Feed the belt over the rest of the pulleys using the guide label or plaque on the face of the engine to set the belt over the grooved pulleys. Turn the alternator adjustment bolt clockwise to tighten the belt until it has the same free play as when you started the project. Tighten the adjustment nut until you can depress the belt only 1/4 inch with your thumb.
Danny Troy Danny, you are super! Thank you so much! This is exactly what I was looking for. Now, when I get the correct impellers and o-rings, I'm confident I can do the job. I ordered parts for the round sea water pump instead of the "D" shaped mercruiser pump, so I need to send them back. I'm at Lake Powell, but maybe I can find the impeller and o-ring in town in Page, AZ. The only catch will be that there doesn't appear to be a seacock to shut off the water. I'll need to plug the hose or block it somehow. Thanks again for your help! Rick Tucson
azcharlie2009 Yes, I have a thru-hull water intake, so there is a seacock. I'm wondering, if you can bend that hose up a bit after disconnecting, to get it above the waterline. No plug is needed if it's above the waterline. Of course, you wouldn't leave the boat in that condition, but working while there is safe. Good luck. It's a PITA job, but there is no alternative. I researched crank mounted pumps and there is no such thing for this engine.
Something very important was missed here. Those pieces of the old broken impeller need to be removed from the system or they may block water flow and cause an overheat. With most systems the first component the water flows to is the power steering cooler and it'll catch all the large pieces. All you gotta do is back flush it before re-connecting the pump. It's a good idea to back-flush even when the impeller hasn't broken apart, ya never know what might be in there.
If you read the comments, I DID mention about back flushing.....just did not put it in the video as I did it in stages and did not video the flushing part.
Thanks for the awesome video. Without that important information about the "tab" I would have been there for hours, you cannot actually see it and the pump just won't come out without knowing you have to twist it out and back in. Also, my experience was that the red hose would not come off the pump while still installed. The red hose is connected to a plastic Y fitting. If you force the red hose too hard you will snap the plastic Y fitting. Mercruiser sells these for $5. There are two other Y fittings like this one on the engine, Mercruiser part number is 862993. Have some extra hose on hand so you can cut the hose off if it will not slide off. Be careful also of the air vent hose on this Y fitting (the 3/4" black hose going up to the top of the engine), it also seizes on and you will snap the Y fitting by forcing this also. Buy some Y fittings before you begin. In the end, I ended up disconnecting the hoses from further down the line on the second engine, this also works well and then you can replace hoses and the Y fitting quite easily.
With my simple trick you break the bond between the hose and nipple using a pick tool to gentle shove in and then spray Silicone/WD40 into the gap. Repeat this 360 around until it's all mechanically broke loose and then showered in lubricant, the hose will fall off. The exception are special barbs that are very sharp sometimes advertised as "no clamp" or something, ya those you got to cut off.
Great video. I have a 2005 5.0MPI Bravo3 on my '98 Sundancer 250 so this is exactly my setup. My impeller was in pretty bad shape so this preventive maintenance really saved me from a bad day at sea. Thanks! ONE QUESTION though. Don't you worry about the missing chunks of impeller? They must be somewhere in the lower black hose. I'm missing about 5 little half-paddle size pieces. The lower hose is a pain since the aft portion is secured with crimp (oetiker type) clamps. Just wondering what the consensus is about that. Anyone?
Many thanks for this Video. It helps a lot for us. I couldn't losen the hosen from the pump. There is no space. I had to do it from the side of the engine...
I don't have the piece sticking out of the mount, you are luck you have tons of room to work on your engine. I have to take the belt, altinator, and tentioner with bracket off...but it is a bit easier to have the hose disconnect on the side off the engine. I just take about 2feet of hose withe the pump..
hey mate... i know 2013 is some time behind^^ but you missed one part in that vid... asking myself how to make sure that the belt has correct/speziefied tension. after putting it in again... do you set marks on the engine? would love to get an answer ;) need to change imp on a mag350 mpi...
Thanks for the detailed video. Can you tell me what the grey piece is to the right of the main pulley, it has a blue plug at the bottom of it? It looks like it drains the water pump? The reason I ask is because when I winterized our boat last fall I did not drain these plugs. Thank you in advance!
Any help is appreciated. We just finished installing a new impeller and put it all back together and installed back to the motor. But no water is coming out the exhaust and running through the engine now… we had water before taking it apart. Now we have nothing. With no water leaking anywhere either…. Any ideas?
I have just changed the manifolds and risers on my 5.0 bravo 2 (2004). While I had the manifolds off I did the impeller on the sea water pump, spark plugs and fuel filters. The motor started well but I am not getting any water circulating at all. Am I correct in assuming there is a problem with the water pump? I did check but maybe I put the impeller in backwards. Thought I would ask before I start work pulling the pump out again. Any ideas? Thanks Phil (Australia)
WOW! Look at those grooves at 4:26 This housing should have been resurfaced or a stainless steel wearplate should have been installed! This boat will definitely overheat prematurely!! those grooves are caused by the old impeller. Putting in a new impeller may work for a while but why not address this problem as well? Do it nice or do it twice! There is a guy on the internet that has sold several hundred stainless wearplates for this exact pump! I am suprised you did not know. He sells on ebay.
I have one to do just like this. Do the hoses have enough slack to pull the pump forward a little. My deck is not removeable and is midship with engine making access very difficult. Am thinking of adapting a crank driven pump like crusader uses on captains choice engines. Any thoughts would be appreciated.
I started my engine and the water pressure at 0....I had a humming noise come for the engine. Shut it down, pulled the boat back out and found a broken impeller.
I could not find a place that sells that impeller. Do they make water shutters and boots out of better material? I hate replacing them. Thank you for the video.
@randybrown9490 can't really help you there. I did a Google search and found that it is a discontinued model from Globe Marine Products. Maybe someone has one on ebay???
how I check my Mercruiser 4,3 with the sea water that's the raw water pumps and I knew to check the hoses for any broken impeller bits that broke off the impeller so my tip is to check all the hoses on the water pumps and related things I knew it important to check if there is broken impeller shards are in the hoses just replace em don't use the hoses that you take off you don't want to be stuck with a damaged sterndrive that will cost you a lot of money in the long run if you are not careful and I knew just check all the hoses on the engines and check em very carefully that's why I have to check all the hoses for bits of the impeller and make sure you see where the hoses are on the engines and replace em if you see bit of impeller from the raw water pump inside the hoses by replacing you'll save a damaged engine in the long run I knew that from my time in the trade as a mechanic working on boats I knew what have to be done
Has anyone ever tried to do this just by removing the Cool Fuel Gen II box and just remove the rear pump housing to get to the impeller?? I'm wondering if it would be easier rather then removing the belt and the whole pump. I had to replace my cool fuel box but at the time didn't think to check the clearance of the pump behind because at the time I didn't know that there was an impeller that had to be replaced at the motor side because my previous boat had an alpha 1 which had the impeller in the stern drive. I have a 2007 SeaRay 240 Sundeck with almost zero clearance and reach room if I had to do this from the front. I know I have to do this job soon because i'm not sure when and if my impeller was changed. Has anyone ever done this job on same make and model as mine with a Cool Fuel Module Gen II ??? If so I'd like to hear how much hair did you have to pull out of your head in order to complete this job lol.
Thanks so much for this vid Bud. Question. Your said your Starboard motor was easier because the bracket came out with the pump on it, right? And on this vid the pump had to be separated from the bracket and you said that was a PITA. I have a 2013 Merc 6.2 Mag 377 with very similar setup to yours, also Gen 3 Cool fuel filter module. Do you think my pump will come out with the bracket (the one you were grinding off) or will I need to struggle to get the pump out by itself? I have very little space (maybe 7 inches between the pulleys and they boat's deck (or gas tank), so I am wondering what I'm in for. In your vid, it looked almost impossible to locate the three bolts that held the pump to the bracket, I don't even think you showed it. Thx
+Chris K. Do you think my pump will come out with the bracket?.....I really can't answer that, the only way to know is to attempt it. I did this video 3 years ago and no longer have this boat but if I remember correctly, removing the rear bracket to pump bolts are easy to locate, just a pain because there was not a lot of room to turn the wrench.
+duboisdl OK, thank you!! I am beginning the work tomorrow. Your vid is very helpful! Thank you so much! Envious of the room you had. I have 6 inches of clearance between the front of the motor and fiberglass wall/gas tank! 24 ft bowrider...
Overdue update.. LOL. Pump will not come out on my boat without separating it from the triangular bracket held to the pump with 3 10mm bolts. Bolts come out easily, then pump with two hoses attached to it comes out nicely too,
Thank you for this great video! This is my second season on a new engine, but I think I might change the impeller before the next one. Do you ever have to replace the bearing/seal on the pump shaft?
great video, I had an issue with my 2004 bravo 3, raw water pulley must have blown a bearing...do u know if I can just change the bearing, or do I have to change the whole unit
Pretty good video but it lacks in showing in better detail how many bolts and their location on the pump that hold the pump to the pump bracket. This is important because my 2005 ski sanger with the Mercruiser 350 mag mpi is very hard to even see where the bolts are and getting to them leaves me bewildered. Lost of stuff in the way.
This pump was a mofo to change. Mines a 350, and this was just an absolute nightmare to change. Make me miss my old OMC. I don't know why Mercruiser decided that this was the best place to stash this pump, AND it really pissed me off that they don't use a sleeve and plate that are replaceable, which is why I had to replace my whole pump, because of the wear grooves in the pump housing, I did not feel it would be wise to reuse; especially with all the time it takes to do this job.
It is always amazing when some one such as this goes out of there way to help and assist others. Well done and thank you. But I do need to point out an obvious step that was missed. The original damaged impeller was missing sections of blades! These are now floating around somewhere in the cooling system! These need to be found and removed or water flow may very well be restricted causing further over heating and damage.
that sensor behind the harmonic balancer is the crankshaft position sensor. Fantastic video, really good camera work and lighting, easy to follow. With the shortage of marine mechanics nationwide these videos are the only things helping owners of older boats to keep them going!
Local dealer wanted to charge over $400 to just change the impeller. 2005 Chaparral 204 ssi. Took about 3 hours total. Can't thank you enough for this video!!!
use 1 zip tie around the new impeller wheel to scrunch it down then coat the housing with soapy water, slide it in and cut the zip tie
yep
It's easier to leave that bracket on the impeller housing and take it off after you get the pump out. You can also leave that pulley on the bracket. Also, an easy way to get the impeller into the housing is to use a hose clamp. Get the fins going in the same direction and tighten the clamp. Then just set the impeller in the pump housing and push it through the clamp.
Hello Sir, your video was a major help to me figuring out how to change the impeller on my 2005 496 MAG's... The Gen 3 fuel setup, pullies, etc... are all the same on mine. Greatly appreciated!
I know you made this video quite a few years ago, but thanks for taking the time to do it!! I picked up a 290 Amberjack last fall, and want to replace the impellers on both engines so i know they are good. This video really helped me prepare for how to tackle this job.
I have a 2007 Larson LXI 268. I sure wish I had the room you have to work. Heck I cant even see the pump and can hardly touch it. Great video, I might just let the dealer do this one for me....
this is the same water pump as mine....I was checking to see if the impeller is off set in the housing. I thought mine was out of wack...all good. Thank you for your video, I can put mine back on after I clean up my pump and bracket.
Thanks for all the good comments guys. I've used RUclips for lots of stuff so I figured I'd contribute.
Sure would like to see a video on a impeller replace on an enclosed cooling system. (2006 496 cu in 375HP)
Raymond Pomaville It's basically the same setup. Same pump housing and hose connections on the rear. The alternator will be on the other side of motor and the cooling water hoses that are around the pump will not be in the way like it is on the 5.0.
kcsmpatter THANKS. Ill be tackling it finally in the next couple of weeks. Will let you know
Appreciate the video!!! Attacking this project tomorrow now!!! How about a video on removing and replacing that fuel cooling module....
You were so right about those back bolts on the gen 3 cool fuel module! They were a bear to get loosened. Thank you for confirming about the worthless tab on the mounting bracket. Next time it will take half the time to complete the job.
Hi. I used your video while doing the work - watching it on my phone. Thanks a bunch - very helpful. I don't have the Gen 3 fuel filter, but still had to remove the pump to get at the impeller. Now, to put it back on.
Thanks for the video. My pump failed and the mechanic at my marina refused the work due to lack of access. My boat only has about 6" between the motor and mid cabin bulkhead. (Rinker 250) Thanks to your video I knew what had to be done and was able to angle a mirror to see all the brackets and hoses and successfully remove the pump. I know the video was a pain to make and edit, but it just might have saved my season! I really owe you one pal, thanks again. Dennis
thank you for the video..excellent..wow....what makes it even harder is space to work with. thats what I am afraid of.
DO NOT FORGET to plug the intake hose (bigger hose) with a 1 7/8 stopper if you are doing this in a slip or you will sink your boat :)
Thank you so much for posting this. Finally think I can get my pump off now.
Great video - big help to me to see things clearly. Thanks for making!
It's called the water distribution housing. On my boat, it's how I drain water / RV antifreeze from the motor. After you flush out your motor with RV antifreeze, it's probably a good idea to remove the blue plugs to drain everything.
Is there some reason that Mercruiser decided to make a yearly maintenance item so goddamn difficult to change?
they changed to a plastic housing which looks easier to maintain. There are also Hardin stainless steel versions of these people recommend and also ditching the unit completely and going to a crankshaft powered version (smaller belt needed)
thank you, your video is very helpful i will take on a project like this this weekend, i wish i had as much room in engine compartment as you
Thanks! I have the same engines in my '08 Sea Ray Sundancer. Doesnt look like a bad job. I'm going to make a little platform board like you have to help me kneel down. Mine's kind of tight in there with a genset in front of the engines.
Yeah, where Mercrusier put the raw water pump can be a nightmare. Most Volvo’s, Crusaders and Marine Power’s only take a few minutes. Change the impeller at least every two years from the time of the install regardless of storage or running hours. If you went too long you may have lots of problems. If you have an oil cooler, much of the impeller debris may be bunched up there. Other places are fuel cooling, small cylinder head passageways and heat exchanger on close systems. Hopefully it went through and out. To lube the impeller, never use petroleum based products, silicone grease is best. Some have used vegetable oil and dish soap, but I can’t judge those.
Good video describing the job on that specific engine. I have the 496 and did the job and it was a bit harder than your procedure. What were they thinking, putting a part that needs regular servicing in the worst possible location! I'm looking to replace with a crank mounted water pump conversion, but after a lot of searching, it looks like it can't be done on the 496, for whatever reason.
Danny Troy I also have the 496 mags, two of them! I wonder if you could give me a few pointers. I'm sure I can replace the impeller and the o ring. But, how in the hell do you get the damn pump out? Any place online I can find information? Darn, I hate to pay somebody to do this... Oh, by the way, can this be done in the water? I thought I could pinch the hoses with a couple of thin boards and clamps, but there isn't much room. Maybe stuff some rags in the hoses?RickTucson, AZ
azcharlie2009 If you need to print out the instructions, this is what I found on a site. Thanks to the original poster. Sorry, I no longer remember who posted it, or where the site was. Also, the video pretty much shows the total procedure. If you can't remove it, is it because the two hoses are still connected? They are the hardest part to deal with, in my opinion. Anyway, here's the procedure:
o 1
Close the seacock. This through-hull valve allows
seawater to come into the pump.
o 2
Note the amount of free play in the serpentine
belt that drives the pump. Loosen the bolt at the top of the alternator that
acts as a hinge. Loosen the alternator adjustment nut with a 19-mm socket and
back the adjustment bolt out approximately 1 inch. Swing the alternator inward,
slacking tension on the belt. Swing the alternator toward the engine as far as
possible and slide the belt from one of the non-grooved pulleys. Remove the
belt and set it aside without turning it over -- it must be reinstalled in the
same orientation as it was in when you removed it.
o 3
Remove the two 19-mm nuts that hold the water pump
and the 20-mm bolt holding the pulley bracket and two pulleys, with sockets of
the appropriate sizes. Remove the bracket and pulleys and set them aside.
Remove the two blue, plastic wing-bolt plugs from behind the pump's port side,
keeping track of the O-rings. Remove the hose clamps from both the outgoing,
bottom hose and the red incoming pump vacuum hose on top of the pump with a
screwdriver. Lift the tab that extends the length of the sensor housing to open
the housing and gain access to the wiring inside. Remove the wiring harness
that runs to the back of the pump. Insert a large, flat-blade screwdriver
between the pump's left side and the engine block and work the pump free.
o 4
Remove the six 10-mm nuts from the back of the
pump with a 10-mm socket and separate the two halves of the pump housing. Lay
the pump face down on the pulley and pull the back half free. Note that the
impeller turns counterclockwise, since you are viewing it from "the
bottom." Make a small mark on the side of the impeller facing you with an
indelible pen, so you may return the same face to the pump. Remove the
impeller, using two small pry bars to lever it if necessary.
o 5
Inspect the impeller and the interior of the pump
housing for damage or wear. Replace the pump housing if it exhibits excessive
signs of wear, from the contents of the pump replacement kit. Replace the
impeller if it shows wear or has broken blades. Lubricate the outer edges of the
propeller vanes and the impeller shaft with white marine grease, if you replace
the impeller. Locate the "Direction of Rotation" arrow inside the
pump. As you install the impeller onto the pump, turn the pulley so the
impeller turns in the direction indicated by the arrow, while you push down on
the impeller to seat it.
o 6
Rub a dab of white marine grease around the edge
of the pump, where you installed the impeller. Place the new O-ring from the
pump kit around the pump's edge. Put marine gasket sealer on the threads of the
bolts that hold the two halves of the pump together. Thread the six 10-mm bolts
back into place and tighten them securely. Thread the two 19-mm bolts through
the pulley bracket and into the water pump, tightening each securely. Bolt the
pulley bracket back into place with the single 20-mm bolt and tighten the bolt
until it is snug. Replace the hose clamps and connect the hoses, tightening the
hose clamps fully with a screwdriver. Reconnect the sensor wiring harness to
the pump, then into the sensor housing. Close the housing and press the locking
tab.
o 7
Replace and tighten the blue-plastic wing-nut
plugs and their O-rings. Slide the serpentine belt over a smooth pulley in the
same orientation in which it was removed. Feed the belt over the rest of the
pulleys using the guide label or plaque on the face of the engine to set the
belt over the grooved pulleys. Turn the alternator adjustment bolt clockwise to
tighten the belt until it has the same free play as when you started the
project. Tighten the adjustment nut until you can depress the belt only 1/4
inch with your thumb.
Danny Troy Danny, you are super! Thank you so much! This is exactly what I was looking for. Now, when I get the correct impellers and o-rings, I'm confident I can do the job. I ordered parts for the round sea water pump instead of the "D" shaped mercruiser pump, so I need to send them back. I'm at Lake Powell, but maybe I can find the impeller and o-ring in town in Page, AZ. The only catch will be that there doesn't appear to be a seacock to shut off the water. I'll need to plug the hose or block it somehow.
Thanks again for your help!
Rick
Tucson
azcharlie2009 Yes, I have a thru-hull water intake, so there is a seacock. I'm wondering, if you can bend that hose up a bit after disconnecting, to get it above the waterline. No plug is needed if it's above the waterline. Of course, you wouldn't leave the boat in that condition, but working while there is safe. Good luck. It's a PITA job, but there is no alternative. I researched crank mounted pumps and there is no such thing for this engine.
THANK YOU ! This engine looks just like my 377 sea core and I have been looking for some help in removing my raw water pump.
Something very important was missed here. Those pieces of the old broken impeller need to be removed from the system or they may block water flow and cause an overheat. With most systems the first component the water flows to is the power steering cooler and it'll catch all the large pieces. All you gotta do is back flush it before re-connecting the pump.
It's a good idea to back-flush even when the impeller hasn't broken apart, ya never know what might be in there.
If you read the comments, I DID mention about back flushing.....just did not put it in the video as I did it in stages and did not video the flushing part.
Thanks for the awesome video. Without that important information about the "tab" I would have been there for hours, you cannot actually see it and the pump just won't come out without knowing you have to twist it out and back in. Also, my experience was that the red hose would not come off the pump while still installed. The red hose is connected to a plastic Y fitting. If you force the red hose too hard you will snap the plastic Y fitting. Mercruiser sells these for $5. There are two other Y fittings like this one on the engine, Mercruiser part number is 862993. Have some extra hose on hand so you can cut the hose off if it will not slide off. Be careful also of the air vent hose on this Y fitting (the 3/4" black hose going up to the top of the engine), it also seizes on and you will snap the Y fitting by forcing this also. Buy some Y fittings before you begin. In the end, I ended up disconnecting the hoses from further down the line on the second engine, this also works well and then you can replace hoses and the Y fitting quite easily.
Stefano Bomben
Thanks for the additional info... It all helps us backyard mechanics👌
With my simple trick you break the bond between the hose and nipple using a pick tool to gentle shove in and then spray Silicone/WD40 into the gap. Repeat this 360 around until it's all mechanically broke loose and then showered in lubricant, the hose will fall off. The exception are special barbs that are very sharp sometimes advertised as "no clamp" or something, ya those you got to cut off.
Great video. I have a 2005 5.0MPI Bravo3 on my '98 Sundancer 250 so this is exactly my setup. My impeller was in pretty bad shape so this preventive maintenance really saved me from a bad day at sea. Thanks!
ONE QUESTION though. Don't you worry about the missing chunks of impeller? They must be somewhere in the lower black hose. I'm missing about 5 little half-paddle size pieces. The lower hose is a pain since the aft portion is secured with crimp (oetiker type) clamps. Just wondering what the consensus is about that. Anyone?
Many thanks for this Video. It helps a lot for us. I couldn't losen the hosen from the pump. There is no space. I had to do it from the side of the engine...
Thanks for the video and explanation.
I don't have the piece sticking out of the mount, you are luck you have tons of room to work on your engine. I have to take the belt, altinator, and tentioner with bracket off...but it is a bit easier to have the hose disconnect on the side off the engine. I just take about 2feet of hose withe the pump..
hey mate... i know 2013 is some time behind^^ but you missed one part in that vid... asking myself how to make sure that the belt has correct/speziefied tension. after putting it in again... do you set marks on the engine? would love to get an answer ;) need to change imp on a mag350 mpi...
Thanks for the detailed video. Can you tell me what the grey piece is to the right of the main pulley, it has a blue plug at the bottom of it? It looks like it drains the water pump? The reason I ask is because when I winterized our boat last fall I did not drain these plugs.
Thank you in advance!
Any help is appreciated. We just finished installing a new impeller and put it all back together and installed back to the motor. But no water is coming out the exhaust and running through the engine now… we had water before taking it apart. Now we have nothing. With no water leaking anywhere either…. Any ideas?
excellent video and a huge help. Many Thanks!
Good video and in goos detail.
I have done the same but on the way putting it back, the pump is wobbling. Any trick to help with alignment?
I have just changed the manifolds and risers on my 5.0 bravo 2 (2004). While I had the manifolds off I did the impeller on the sea water pump, spark plugs and fuel filters. The motor started well but I am not getting any water circulating at all. Am I correct in assuming there is a problem with the water pump? I did check but maybe I put the impeller in backwards. Thought I would ask before I start work pulling the pump out again. Any ideas?
Thanks Phil (Australia)
WOW! Look at those grooves at 4:26 This housing should have been resurfaced or a stainless steel wearplate should have been installed! This boat will definitely overheat prematurely!! those grooves are caused by the old impeller. Putting in a new impeller may work for a while but why not address this problem as well? Do it nice or do it twice! There is a guy on the internet that has sold several hundred stainless wearplates for this exact pump! I am suprised you did not know. He sells on ebay.
I have one to do just like this. Do the hoses have enough slack to pull the pump forward a little. My deck is not removeable and is midship with engine making access very difficult. Am thinking of adapting a crank driven pump like crusader uses on captains choice engines. Any thoughts would be appreciated.
How long (time) did it take to R&R the impeller?
I started my engine and the water pressure at 0....I had a humming noise come for the engine. Shut it down, pulled the boat back out and found a broken impeller.
I'm glad it helped you out.
I could not find a place that sells that impeller. Do they make water shutters and boots out of better material? I hate replacing them. Thank you for the video.
Gosh, that was over 12ish years ago I'm sure that any dealer that sells your make of boat would be able to provide a part number.
I’m talking about the run dry Globe impeller.
@randybrown9490 can't really help you there. I did a Google search and found that it is a discontinued model from Globe Marine Products. Maybe someone has one on ebay???
how I check my Mercruiser 4,3 with the sea water that's the raw water pumps and I knew to check the hoses for any broken impeller bits that broke off the impeller so my tip is to check all the hoses on the water pumps and related things I knew it important to check if there is broken impeller shards are in the hoses just replace em don't use the hoses that you take off you don't want to be stuck with a damaged sterndrive that will cost you a lot of money in the long run if you are not careful and I knew just check all the hoses on the engines and check em very carefully that's why I have to check all the hoses for bits of the impeller and make sure you see where the hoses are on the engines and replace em if you see bit of impeller from the raw water pump inside the hoses by replacing you'll save a damaged engine in the long run I knew that from my time in the trade as a mechanic working on boats I knew what have to be done
The Run dry impeller from Globe Marine has been discontinued. Has anyone found a replacement?
Great video. It was indeed
Thanks, great tutorial!!
Has anyone ever tried to do this just by removing the Cool Fuel Gen II box and just remove the rear pump housing to get to the impeller?? I'm wondering if it would be easier rather then removing the belt and the whole pump. I had to replace my cool fuel box but at the time didn't think to check the clearance of the pump behind because at the time I didn't know that there was an impeller that had to be replaced at the motor side because my previous boat had an alpha 1 which had the impeller in the stern drive.
I have a 2007 SeaRay 240 Sundeck with almost zero clearance and reach room if I had to do this from the front. I know I have to do this job soon because i'm not sure when and if my impeller was changed. Has anyone ever done this job on same make and model as mine with a Cool Fuel Module Gen II ??? If so I'd like to hear how much hair did you have to pull out of your head in order to complete this job lol.
ever find out, I'm about to do the same on my Cool Fuel Gen 2 350 Mag
yeah but just a bit. You should be able to tell just by looking at the hoses
Thanks so much for this vid Bud. Question. Your said your Starboard motor was easier because the bracket came out with the pump on it, right? And on this vid the pump had to be separated from the bracket and you said that was a PITA. I have a 2013 Merc 6.2 Mag 377 with very similar setup to yours, also Gen 3 Cool fuel filter module. Do you think my pump will come out with the bracket (the one you were grinding off) or will I need to struggle to get the pump out by itself? I have very little space (maybe 7 inches between the pulleys and they boat's deck (or gas tank), so I am wondering what I'm in for. In your vid, it looked almost impossible to locate the three bolts that held the pump to the bracket, I don't even think you showed it. Thx
+Chris K. Do you think my pump will come out with the bracket?.....I really can't answer that, the only way to know is to attempt it. I did this video 3 years ago and no longer have this boat but if I remember correctly, removing the rear bracket to pump bolts are easy to locate, just a pain because there was not a lot of room to turn the wrench.
+duboisdl OK, thank you!! I am beginning the work tomorrow. Your vid is very helpful! Thank you so much! Envious of the room you had. I have 6 inches of clearance between the front of the motor and fiberglass wall/gas tank! 24 ft bowrider...
C. K.
I literally had to take a sawzall to my boat to get my pully and pump out! 0 room
Overdue update.. LOL. Pump will not come out on my boat without separating it from the triangular bracket held to the pump with 3 10mm bolts. Bolts come out easily, then pump with two hoses attached to it comes out nicely too,
Thank you for this great video! This is my second season on a new engine, but I think I might change the impeller before the next one. Do you ever have to replace the bearing/seal on the pump shaft?
Sorry I have not. I sold this boat 4 years ago and my current boat is a different design (Volvo Penta)
Thanks!
Great video but I can't seem to find that pn impeller.
That video is over 9 years old. That part number is no longer available. I don't know what the replacement number is as I no longer own that boat.
great video, I had an issue with my 2004 bravo 3, raw water pulley must have blown a bearing...do u know if I can just change the bearing, or do I have to change the whole unit
I'm really not sure. I no longer have that boat so I can't check it out.....sorry
Good video, but you forgot to check where is the old broken impeller.It still stay inside the hoses that can block the way and overheating again.
I did check but not in the video, it was done in stages and I kind of forgot to add it in
How do you back flush the motor then to make sure you get all of those broken parts out.
does a Volvo penta 280 low unit has water impeller?
how hard or easy does the pulley on this pump move.....I have mine off the motor and cleaning up all the brackets from rust.
I did this video 4 years ago and no longer have that boat but from what I can remember, without the impeller, it spins pretty easy
I guess I should take the impeller out and test it...I just visually inspected it. Thank you.
Pretty good video but it lacks in showing in better detail how many bolts and their location on the pump that hold the pump to the pump bracket. This is important because my 2005 ski sanger with the Mercruiser 350 mag mpi is very hard to even see where the bolts are and getting to them leaves me bewildered. Lost of stuff in the way.
There wasn't on mine!!!
This pump was a mofo to change. Mines a 350, and this was just an absolute nightmare to change. Make me miss my old OMC. I don't know why Mercruiser decided that this was the best place to stash this pump, AND it really pissed me off that they don't use a sleeve and plate that are replaceable, which is why I had to replace my whole pump, because of the wear grooves in the pump housing, I did not feel it would be wise to reuse; especially with all the time it takes to do this job.
Thanks for the Video. Going to try doing this job. I`ll let you know how I make out.
does the pump need to be primed ??
Jenna DiMisa No it doesn't.