Raw Water pump - rebuild or replace?

[Juliet 15]

I finally finished replacing all 8 mounts under our 4-71s. My wife helped too - beautiful grease monkey... I also completed an alignment (first time). The old mounts had been shimmed with 1/2" pieces of aluminum. I reinstalled the shims as they were only to discover they put the engine waaay too high. So, i had to disassemble each mount, remove the shims, reassemble. But once I was done moving the engines around I had a perfect alignment. Pretty sweet. Thank you to those who chipped in advice - it was invaluable. While doing this I noticed some salt flowering out of the back of one of my raw water pumps. I'm assuming that's a seal failure.



1. Would you guys recommend a seal replacement, a rebuild, or a replacement of the pump?



2. Where do you go for parts? The places I've looked on line are all over the place on prices and availability...



3. How big of a deal might this be? IOW, do I need to do this before the next outing?

 

[syjos]

While doing this I noticed some salt flowering out of the back of one of my raw water pumps. I'm assuming that's a seal failure.



1. Would you guys recommend a seal replacement, a rebuild, or a replacement of the pump?



2. Where do you go for parts? The places I've looked on line are all over the place on prices and availability...



3. How big of a deal might this be? IOW, do I need to do this before the next outing?

I would rebuild it if it is truely leaking. If the seal is leaking, the bearing will go next from salt water. That's why I said if it's leaking because if it was leaking salt water, the bearing would have failed by now or making noise.

For parts or a new pump, Fisheries Supply or Depco Pumps.

A lot depends on if you are doing the work yourself or hiring out. The people you hire will provide parts.

It might be a big deal or not but I'd resolve the pump issue before an extended outing.

 

[O C Diver]

I base rebuild versus replacement on hours on the pump as well as parts versus cost of new pump. To me, a pump rebuild includes bearings water and engine seal, compression fork, front plate, rear cover, and impeller. Now if you're only going to repair what's leaking, that's different. Regarding engine hours, the impeller wears the bore of the pump just as it wears down the compression fork. Before deciding, you might want to remove the compression fork and see how snug a new impeller fits the bore.

Ted

 

[Bmarler]

I’d give the pump a cleaning first, then a little test to see if it’s really leaking. If you rebuild, to add to ocd’s list, be prepared to replace the shaft as well. Crusty salt around the seal can wear the shaft.
I keep a complete spare raw water pump on board so I can swap out and rebuild at my leisure.

 

[TBill36]

Don't know what engines you have, but rebuilding them yourself can save money. Get as many part numbers as you can from your engine parts book to what's on the old pump and search the internet. If it's Jabsco or Sherwood, try search those also.
Bearings can usually be found very inexpensively if you look them up by the number on the bearing. Same for seals if you can find part numbers for them. Sometimes the hardest part is getting the pully off. My friend destroyed his and he's reasonably competent with mechanical abilities. It's also nice to have a spare ready to go that you can just swap out if needed.

 

[Juliet 15]

71 All good input. I'm going to do the work myself. I don't think it's leaking water, no sign of that. Just blooming white and blueish salt on the opening at the back where you can see the shaft leaving the pump. Engines are Dd 4 71

 

[sunchaser]

71 All good input. I'm going to do the work myself. I don't think it's leaking water, no sign of that. Just blooming white and blueish salt on the opening at the back where you can see the shaft leaving the pump. Engines are Dd 4 71

I echo what Ted said on total rebuild Vs partial. Once the pumps start weeping some "salts" appearing are often an indicator.

Price out a new one vs a total rebuild. Having a rebuild as a spare vs a new one in place is an option to consider, especially if you are cruising more than a few miles from home port.

Plus you have a great assistant grease monkey to do the work. What a bonus

 

[Slowmo]

Depending on cost I'd buy a replacement pump AND then rebuild (or have rebuilt) the current pump. I did that on our boat, replaced both RW pumps but the old ones rebuilt as spares. I always like to have a spare on board since I've had seals seals go from a drip to a spraying water (off the shaft).