Raw water pump leaking from the drain hose (Lombardini)

[Mantas]

Hello engine experts,
I need some help to understand why my generator (Paguro with Lombardini LDW 502M engine) started to leak from the water pump">raw water pump. I was surprised that this pump has a small drain hose which was not going out of the generator casing, so it was wet inside and full of salt. Can anyone advise me on what could be the problem? Thank you.

[Jim Cate]

Not familiar with Lombardini engines, but it sounds like a leaking shaft seal on the pump. The Johnson pumps that many engines use just have a small port for exiting leakage and it sounds like your pump has a hose appended to the port to direct the leakage away from the engine.

I believe you need to renew that seal asap, for it will only get worse with time. On Johnson (and similar Jabsco) pumps it is fairly simple to do so, and replacement seals are inexpensive and readily available at regular "seal and bearing" shops worldwide.

Jim

[Lepke]

Usually the bearings get worn and allow the shaft to distort the seal. Both bearings and seal need to be replaced. Most coolant pumps need the pulley pressed off and then the shaft and impeller come out the back. Raw water pumps can usually be rebuilt with hand tools.

[Mantas]

Thank you all, changed seals today and it stopped leaking. Hope this fast fix will hold for some time until I get new bearings and shaft.

[jamhass]

If your shaft is badly worn and expensive (as many are) you might consider a shaft repair sleeve. These are thin cylinders that can be placed over worn areas of a shaft to give the seal a nice smooth area to bear on.

[Jim Cate]

Originally Posted by Mantas

Thank you all, changed seals today and it stopped leaking. Hope this fast fix will hold for some time until I get new bearings and shaft.

Was there palpable play between shaft and bearings? If not, likely they are still ok. IME the bearings (again in Jabsco/Johnson pumps) will last through several seals and impellers. Yours may be different!

Jim