Oil Seals

[Toulla]

2001 F25ELHZ. What other way can water enter the lower unit besides the lower oil seal? Mechanic says Yamies are known to allow water to enter at the gear shift rod. Engine has 500 Hours and it never had water in the lower unit before. Fishing line or anything else has never found it's way around the prop.
Thanks for your input.

[Sequoiha]

Prop shaft, Shift shaft, Drive shaft, and both drain plugs, the drain plug gaskets are made of fiber, i would replace them every time, even when they look good they can still leak.

[Toulla]

Oils seals

Thank you! I am planning on replacing the water pump and it's housing while the lower unit is off the engine. Given the age of the engine should I go ahead and have all three suspected areas changed? The washers are not the issue, I always use new ones after an oil service, so it must be one of the seals.
Thanks again for your help.

[99yam40]

Pressure and vacuum test should show where your problem is

[Toulla]

Oil seals

Yes,
I am sure the mechanic will perform both tests; I will insist on that. However, given the age of the engine, should I have all three seals replaced? Even if only one is leaking at this time. By the way, it is really a minimum amount of water that managed to get in during 50 Hrs of operation. Then again, we all know how small leaks become LARGE leaks very quickly on boats. Thanks for your input.

[99yam40]

Never hurts to do all if they have never been done before

[Toulla]

Oil seals

Thank you both for your response. I will have them all replaced.
By the way, does this model have a pressure relief valve? I don't see it on the parts diagram.
Thanks again.