Seals on Raw Waterpump - Leaking

[geoffr]

I have a 3YM30AE with a Johnson water pump">Raw water pump. Ours is current leaking. We are having a hard time finding parts here in Mexico..... So do they get worse quicky or just slowly get worse? If we can find the parts and it's not a big deal we'll wait until we get to the US.

(I'm pretty sure it's the lip seal that's going which isn't surprising given the years/engine hours we've used the engine)

[Uncle Bob]

Originally Posted by geoffr

I have a 3YM30AE with a Johnson Raw water pump. Ours is current leaking. We are having a hard time finding parts here in Mexico..... So do they get worse quicky or just slowly get worse? If we can find the parts and it's not a big deal we'll wait until we get to the US.

(I'm pretty sure it's the lip seal that's going which isn't surprising given the years/engine hours we've used the engine)

Can you find an industrial bearing supplier near you? If so take the old seal to them and they should be able to supply a new one and if you really want to "marinise"it remove the garter spring and replace it with an o ring of the same size.

[Wotname]

^^ what Uncle Bob said +1

The seals are common industrial seals which should be available at any bearing / seal supplier. They aren't Yanmar or Johnson specific!

You can measure the housing (outer) diameter, the shaft (inner) diameter and the thickness and find the seal and manufacturer's part number on line.

They sometimes get worse slowly, they sometimes get worse fast - are you a betting man?

[SailingHarmonie]

I have seen a number of engines ruined by slow salt water drips. The corrosive effects of salt water are easy to ignore because it is so common. But it is very, very nasty. Just get it fixed, asap.

Any long distance cruising boat should be carrying a spare raw water pump ready to install. It is usually the fastest way to get back up and running leak free.

[Rapanui]

The seals are standard 24 od 12 id 7 deep lip seals you should be able to buy at any bearing shop. If you take the impeller out you can hook the old seal out with a hooked pik e.g. a dental pik and then push the new seal in using an appropriately sized socket and hammer.
As others said, leaving it leaking will spray salt over the engine and eventually ruin the pump bearings requiring a full rebuild.
We replace the seal every year when we replace the impeller, 8 years so far and no pump rebuild required.

[geoffr]

Good news - I was finally able to find a lip seal and replaced ours - no leak so far
(I didn't replace the bearings although I do have a set if needed later).

[Jim Cate]

Originally Posted by geoffr

Good news - I was finally able to find a lip seal and replaced ours - no leak so far
(I didn't replace the bearings although I do have a set if needed later).

Well done! I hope that you bought a few extra seals, for as the shaft ages they tend to fail sooner and sooner. Now that you have done the job once and know how easy it is you will be ready to attack any future leaks promptly, no matter where you may be.

The advice to have a complete spare pump is well thought out too. Means that one can do the actual repairs at leisure whilst the spare is pumping away.

Jim

[geoffr]

Jim - yes I've been thinking I'll buy a spare pump when I'm back in the US. Any suggestions as to who carries the F4B-903 (Yan: 128995-42500) for a good price (shipping to Florida)