Thread: vacuum leak
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CalifBill CalifBill is offline
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First recorded activity by BoatBanter: Jul 2006
Posts: 870
Default vacuum leak


"Jim" wrote in message
nk.net...

"James" wrote in message
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Ran it in the water? Or on a trailer? Cause they usually don't get
water in them unless they are in water. The exhaust water is not usually
enough. A few minutes is not usually enough either. Check for fishing
line around the prop shaft. That is a common problem. Did you see the
oil? Sometimes it takes a couple oil changes to get all the signs of
water out as the oil is thick and does not drain well. If it has a seal
problem it will be the input shaft, the prop shaft, or the shifter seals.
Most people just replace them all as it is diffcult to pin down the
culprit. The seals are a pain to remove as well.

If you do some of your own work you could change the oil again and run it
for a while then check it. When I first got my boat it has some signs of
water in the lower unit. I changed the oil and have never had a problem
since. But I change the lower unit oil regularly. And check it for
signs of water regularly. If the original owner never changed the lower
unit oil they do sometimes eventually get a little water in them.

Is this the same marina that services the boat for the prior owner? Thay
may be able to tell you the maintenance history. Have you had previous
good experiences with them? Marinas can be worse than car repair places.

"SueEZ" wrote in message
oups.com...
I bought a 1994 Sea Ray SC2100 this spring. I had it winterized this
fall and the Marina told me the lower unit oil was milky white,
indicating water was leaked in. They filled the unit with new oil, ran
it for a few minutes and drained it again with the same results. They
then performed a pressure and vacuum test. The pressure test passed,
but the vacuum test failed. It would not hold a vacuum. I have never
had a boat fail either test or have water leak. Before moving forward
with a repair, I'd like to understand what could be the problem and the
estimated cost associated. Can someone offer me some advice?



The big seal on the yoke is the prime suspect for a vacuum leak. Unless
oil leaks into the bellow, I wouldn't worry too much about that. James
suggested changing the oil again. I think that is a good idea. If the
pressure test passed, you might have a bad fill/drain seal. Removing the
top cover for inspection might reveal weather you should be optimistic
that the internals are OK. There's usually a magnet on the bottom drain
plug. Anything attached to it? was the oil inspected for suspended
metallic particles? Any debris in the oil collection pan? When the engine
was running were there any unusual noised from the stern drive? Did It
shift OK? How did the gear oil look when you bought the boat?

It's going to cost you a couple of hundred beyond what you've already
spent, just to get an accurate estimate of repair costs.

The good news is that prices on new replacement drives is way down. That
might be an alternative if the estimate is too high.
Jim


The shaft seal is double lip seal. So one side is probably bad. Would be
the outside edge, and fishing line behind the prop will destroy the seal.
Only one I changed was on a 15hp mariner, and was not a huge or expensive
job.