Pressure testing lower end.

[NH TOONER]

Can anyone tell me the process for pressure testing a lower end? 1995 225 hp merc.

 

[Docksidemarineservices]

Drain the gear oil, remove the lower unit from the engine, hook up a coolant system pressure tester to the lower drain plug using the screw fitting from a gear oil fill pump and pump about 13lbs into it. Listen for leaks. You can spray some soapy water on it to look for leaks also.

 

[fastjeff]

I only test for vacuum, for that's how water gets in. If the seals leak a bit under pressure, big deal: some oil leaks out. There's plenty left (and very little is needed to lube the bearings and gears, possibly less than 50 %). A few tablespoons of water getting in, however, and it's curtains for it destroys the oil's ability to lubricate.

Jeff

 

[NH TOONER]

Thanks. This is for a motor I was tinking of buying. Just wantes to check as much as possible.

 

[racerone]

If the seller agrees then it is a very good idea.------------------You pay for the new oil / labour at a shop if need be.----------------Lower units can be expensive to repair.------------------Pressure test and vacuum test.

 

[faztbullet]

Dont put more than 8psi in it as it will pop the front shift shaft seal.....

 

[fastjeff]

Right! The best test of an LU is to pull the plug and eyeball what comes out: If it's water RUN away!

Jeff