Logo
FULL SITE MENU

Water in gearcase

C

Csh

New member
Hi, thanks for any help in advance.

I have a new to me 1992 4hp outboard. It looks very lightly used. I drained the lower unit and water came out. Not just milky oil, approximately 2-3 ounces of straight up water followed by milky gear oil. When I took the drain screws out the gaskets half crumbled off/half became one with the metal. After scraping the old gasket off and replacing them, I did a pressure test and it holds 10-12 psi without leaking.

Am I safe to assume the drain screws were leaking that much?

Thanks again.

CSH
 
I guess so. The pressure test is usually the pass-fail criteria. I'd replace the oil, run it a few minutes to get it well distributed and drain and refill with new after what you said you had. On the be safe side, periodically check the oil to ensure you don't have a shaft seal leaking too...prop shaft, drive shaft, shift shaft. Then a good looking over for a cracked casting....from that water expanding during a hard freeze and breaking the LU casting.
 
Last edited:
Csh said:
Hi, thanks for any help in advance.

I have a new to me 1992 4hp outboard. It looks very lightly used. I drained the lower unit and water came out. Not just milky oil, approximately 2-3 ounces of straight up water followed by milky gear oil. When I took the drain screws out the gaskets half crumbled off/half became one with the metal. After scraping the old gasket off and replacing them, I did a pressure test and it holds 10-12 psi without leaking.

Am I safe to assume the drain screws were leaking that much?

Thanks again.

CSH
Click to expand...


the pressure test is good, but you should also do a vacuum test. it is possible that a seal holds in one direction but not the other.
 
coasty14 said:
the pressure test is good, but you should also do a vacuum test. it is possible that a seal holds in one direction but not the other.
Click to expand...
Thats an interesting point. When the water is cooler than the lower unit....an every day occurrence in the summer months, just like your trailer axle hubs, every time you back your trailer into the water, as the LU and fluid inside cools it forms a partial vacuum which could assist water entering via a defective seal.....course it wouldn't be all that much of a vacuum, but would none the less be a negative pressure.
 
Back
Top