Raw water pump leaks

[santa margarita]

We have a Yanmar 4jh3e. The water pump">raw water pump is leaking. I looks like the water is coming from the exposed shaft that drives the pump. Do I need to replace the whole pump or is it possible to replace the seals? And can I do damage by leaving it leak 'til the end of summer?

[David M]

The seal on the back is leaking. It could be that the bearings are going out or both. I would purchase a professionally rebuilt pump. What you don't want is a bearing failure. You have some time left on it but it is impossible to say how much time. I would definitely replace it sooner than later.

[santa margarita]

Thanks David, I'll see what I can find in Victoria

[SkiprJohn]

I agree with David. Replacing with rebuilt is much much easier than trying to replace a bearing in the old pump. Failure in your pump when you need your engine most could be a catastrophe. So, yes replace it and yes do it sooner.
JohnL

[Sandero]

I don't know your pump, but my Volvo rw pump has a pair of shaft seals which when shot will cause a leak at the shaft. It's definitely user serviceable. I did it. If yours is similar I would get the seals and give it a go.

Having a spare RW pump is an excellent idea. Order a replacement and rebuild the old one as a spare especially if you are crusining.

[santa margarita]

OK that makes sence defjef. I'll try to find a parts manual.

[speciald@ocens.]

Check the pump for manufacturer; its usually on the front plate. You can buy a new impeller w/ seal for about the same price as the impeller alone. Water is coming through the weep hole and indicates the seals are shot. On the other hand , I like to carry a spair pump that I can install if the impeller fails. It is usuaally easier to replace a pump than an impeller in a sea way.

[santa margarita]

I just took another look at the pump. There are 4 bolts to remove the pump from the engine. There appears to be a problem with one of the bolts in that it is a quarter inch from the engine mount. Is it possible to replace the seal from the impeller end leaving the rest of the pump on the engine?

[speciald@ocens.]

Is it a Johson pump? If so, yes it is possible. Pull the impeller. Behind it there should be two seals separated by a bronze washer or diaphragm. Pull the seals out and replace with two new ones; be sure to orient the two new ones in the right direction.

[SkiprJohn]

Just so you know. I was talking about bearings and not seals. Bearings are hard to replace in Jabsco pumps. Impellers and seals are not so bad.
Kind regards,
JohnL