How To: Rebuilding Merc Sea/Fuel Pump
#1
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Thread Starter
How To: Rebuilding Merc Sea/Fuel Pump
Seeing that there have been a few recent threads on the Merc Sea/Fuel pumps I thought I would share the rebuild of mine. And the seals and bearing that I used. I am not a professional so don't flame me to much.
For the record I use electric fuel pumps and just cap these off, but I found out the hard way that they still need maintenance. If I could find an inexpensive HI Performance pump I might switch back to mechanical.
1. I used an Arbor press at work and pressed off the pulley. Make sure you put 1/4" spacers under the pulley so you do not bend it. You need to put the pressure on the inner part of the pulley.
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2. I took a screw driver and punched into the seal and pried it out.
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3. I removed the expansion clip.
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4. I knocked out the shaft: supporting the housing with wood and hitting the shaft with a hammer and a piece of wood in between. The front bearing will come out with the shaft.
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5. I used a punch and knocked the inside bearing into fuel pump cavity. You can wiggle the bearing out through the cam arm opening or gently knock it through the front bearing area.
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6. I then used a socket and extension and knocked the 2 smaller seals out that are between the inner bearing and impeller. They use 2 seals: one to keep the oil in and one to keep the water out.
For the record I use electric fuel pumps and just cap these off, but I found out the hard way that they still need maintenance. If I could find an inexpensive HI Performance pump I might switch back to mechanical.
1. I used an Arbor press at work and pressed off the pulley. Make sure you put 1/4" spacers under the pulley so you do not bend it. You need to put the pressure on the inner part of the pulley.
.
.
2. I took a screw driver and punched into the seal and pried it out.
.
.
3. I removed the expansion clip.
.
.
4. I knocked out the shaft: supporting the housing with wood and hitting the shaft with a hammer and a piece of wood in between. The front bearing will come out with the shaft.
.
.
5. I used a punch and knocked the inside bearing into fuel pump cavity. You can wiggle the bearing out through the cam arm opening or gently knock it through the front bearing area.
.
.
6. I then used a socket and extension and knocked the 2 smaller seals out that are between the inner bearing and impeller. They use 2 seals: one to keep the oil in and one to keep the water out.
Last edited by Rookie; 06-22-2010 at 09:32 AM.
#2
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Thread Starter
Parts These are the bearings and seals that I used. At my bearing supply shop using micrometers we came up with a Metric bearing.
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Assembly Sorry not to many pics. Posting this was an after thought.
1. I put the shaft into the freezer to shrink it so I could get the bearings on easier. I greased the inside and outside of the bearings. Once cold I rested the bearings (6204-2RS/C3 $13.90ea) on wood and then the hammered the shaft through the bearings, using wood in between shaft and hammer. One bearing on each side of the shaft.
2. I then put the 2 smaller seals (CR-7464 $4.95ea) in backside of the housing 1 facing the opposite way than the other.
3. I then hammered both bearings through the front bearing opening. Don't forget to put some grease in the housing.
4. I put the expansion clip back on. (sorry blurry pic)
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5. Finally I put the front seal (7690 $7.85ea) over the shaft and seated it in the housing.
.
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Assembly Sorry not to many pics. Posting this was an after thought.
1. I put the shaft into the freezer to shrink it so I could get the bearings on easier. I greased the inside and outside of the bearings. Once cold I rested the bearings (6204-2RS/C3 $13.90ea) on wood and then the hammered the shaft through the bearings, using wood in between shaft and hammer. One bearing on each side of the shaft.
2. I then put the 2 smaller seals (CR-7464 $4.95ea) in backside of the housing 1 facing the opposite way than the other.
3. I then hammered both bearings through the front bearing opening. Don't forget to put some grease in the housing.
4. I put the expansion clip back on. (sorry blurry pic)
.
.
5. Finally I put the front seal (7690 $7.85ea) over the shaft and seated it in the housing.
#4
Registered
Very nice
Only one question
"I put the shaft into the freezer to shrink it"
I thought cold made things expand and get bigger
Only one question
"I put the shaft into the freezer to shrink it"
I thought cold made things expand and get bigger
#5
Charter Member
Charter Member
Nice job, thanks for taking the time. Those part numbers will come in real handy too
#6
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Thread Starter
I hope you are just kidding. When you machine steel you can not get an accurate measurement until the steel is at ambient temperature. Heat expands, cold shrinks.
I will post my How To: Making a Plexiglass hatch later today. I posted it in the Scarab forum and I'll try to move it over here.
#9
Registered
Thanks for the help! Just used this pictorial to rebuild my sea pump for $32 after tax and overnight shipping.
I also added a valve to the bottom of the housing to drain the oil and check for water intrusion.
I also added a valve to the bottom of the housing to drain the oil and check for water intrusion.
#10
Registered
Thread Starter
Did you use the Merc seal part # 13 and 19. The 2 Merc inner seals (26-90562) work better than the SKF 7464?
http://www.mercruiserparts.com/Show_...%28DESIGN+I%29
http://www.mercruiserparts.com/Show_...%28DESIGN+I%29