Raw Water Pump Teardown

[rkmason]

Has anyone done a complete teardown of a Johnson Pump F6B-9 crank-driven raw water pump? How does the driveshaft come out? Is it pressed out leaving the water seals and driveshaft bearings in the housing? Thanks

[Sodar]

I took my pump into the local guy last year with new bearings, seals, impleller, etc. He said "just buy a new pump" So, I figured why not destroy this one if I am going to have buy another one!?!

To answer your question, yes the shaft is pressed in. I had a problem when I pressed mine out, half the bearing stuck to the shaft. I ended up needing to get a bearing puller to get it off. I ended up getting the whole thing rebuilt and mounted, but it had an ugly wobble to it, so I ended up just buying a new one for $130.

[[email protected]]

Don't waste your time. 3 hexhead screws and one at the base of the pump and you are done. A rebuild kit with a bearing kit is about $60

No guarentee that it will work

Just buy a new pump. A new impeller comes with it

[email protected]

[beef]

Don't waste your time. 3 hexhead screws and one at the base of the pump and you are done. A rebuild kit with a bearing kit is about $60

No guarentee that it will work

Just buy a new pump. A new impeller comes with it

[email protected]

+1

I researched the rebuild this past summer and just decided to buy a new pump. Installed it in 15 minutes and back to skiing. Done.

[rkmason]

I already have a new replacement pump; just considering a total rebuild of my old pump so I can start swapping the two periodically. I hate to just throw the old one away if I can rebuild it. Maybe I'll take a shot at the rebuild and if it gets messed up THEN I'll toss it.

[rkmason]

Well, I went ahead and rebuilt my old raw water pump just to see if I could. I have it back on the boat and it runs fine w/no leaks.

The tricky bit was pushing the driveshaft and bearings out of the pump housing without damaging anything. When Johnson builds these pumps they make sure the bearings stay in the pump housing by hammer punching the bearing housing OD in one spot. I drilled that hammered spot out to help relieve the pressure and the bearings and shaft came out without much trouble.

I found the SKF brand bearings and an near-OEM equivalent water seal at an online bearing supply house. My total parts cost was about $20. If you are willing to use Chinese no-name brand bearings the parts cost can be reduced to about $10.

To retain the bearings I drilled and tapped three holes around the bearing housing for very short 8-32 setscrews. Now I have a pump I can easily rebuild the next time.

So you can rebuild your raw water pump yourself if you are so inclined. Most people will still probably just buy a new replacement, but where's the fun in that?

[TMCNo1]

Thanks for the effort and the information for those with Johnson pumps!

[Prostar Rich]

I don't mean to get off subject but how long does the raw water pump last? What kind of life did you guys get before rebuilding or replacing?

Thanks,
Prostar Rich

[Slinkyredfoot]

With the exception of replacing impellers over the years, I finally totally rebuilt my original last winter for the first time, a 1979 PCM.

[rkmason]

I don't mean to get off subject but how long does the raw water pump last? What kind of life did you guys get before rebuilding or replacing?

Thanks,
Prostar Rich

The pump I rebuilt was 10 years / 470 engine hrs old. I cannot say there was really anything wrong with either the bearings or the seal that I replaced so I guess it had some (maybe alot) of life left in it. I did my pump rebuild more just to see if I could do it myself. I'll definitely go longer this time around.

[Prostar Rich]

The pump I rebuilt was 10 years / 470 engine hrs old. I cannot say there was really anything wrong with either the bearings or the seal that I replaced so I guess it had some (maybe alot) of life left in it. I did my pump rebuild more just to see if I could do it myself. I'll definitely go longer this time around.

Thanks for the info. Last year I has chasing down an overheating issue and the RWP checked out however the boat is a 1990 with about the same hours as listed above. I was just wondering what kind of life I should get out of it.

Thanks again,
Prostar Rich

[Tom023]

You might want to take a look at this, posted by Engine Nut sometime ago. I disassembled mine to replace the shaft seal without any special tools, but if you are replacing the bearings, looks like some are needed.

[flipper]

I have to agree with most of the above....get a new one. Much less of a head ache, and no worries of messing something up, and having to replace it anyway.

[rkmason]

You might want to take a look at this, posted by Engine Nut sometime ago. I disassembled mine to replace the shaft seal without any special tools, but if you are replacing the bearings, looks like some are needed.

Yes, that is pretty much exactly what I did, but without the luxury of a press. At a minimum you do need a puller to get the bearings off of the pump shaft.

[Chief]

After tearing mine out today, I think I will buy a new one. I have a small leak and as much as a pain it was to get it out, I'm not risking a rebuild!