mercury lower unit oil leak

[rld1017]

My 175 mercury lower unit has a heavy oil leak Seals and o-ring were replaced but it made no change. Could not find any damage in unit when it was apart and no water was in unit. OEM parts were used . can oil come from anywhere else like around water pump Ronnie

 

[Chris1956]

Re: mercury lower unit oil leak

Ronnie. The gearcaser has seals at the driveshaft under the waterpump, the shiftshaft and the bearing carrier and propshaft. It also has gaskets on fill and drain plugs. The waterpump base has the driveshaft seal. If it is leaing out the water intakes, or not by the propsahft, that is your likely problem.

 

[rld1017]

Re: mercury lower unit oil leak

What I found was the oilpressure check valve was not releasing pressure. When I took the oil cap off the tank a week after motor was run it was still under pressure. It was pushing oil out and flooding motor