Power trim losing pressure on 75 horse Mariner

[starkyb]

My 75 horse Mariner slowly loses pressure when trimmed up. A mechanic told me it was probably a valve that went bad and didnt think that it was a big deal to fix. When I looked at a schematic of the trim assembly it showed a screw on the side with some little o-rings near the tip. The whole thing is called the valve assembly. Is this what he is talking about. He also mentioned that the tip can break off inside of the pump.

 

[Laddies]

Re: Power trim losing pressure on 75 horse Mariner

The first place to look is the manual release valve o rings, thats the one in the starboard side mount, you will have to remove the e clip to get it out, you did not give a serial# or year so it takes some guessing which is not good but if its the 3 ram system there is a valve in the port ram that can also cause leak down, don't try to take it apart just flush it with light oil as it is preset and disassembly will destroy it's setting. Other than these 2 things you will need a manual and some speical tools or a lot of luck.

 

[starkyb]

Re: Power trim losing pressure on 75 horse Mariner

The serial number is OB262791 and it is a 1988.

 

[starkyb]

Re: Power trim losing pressure on 75 horse Mariner

I'm sorry but I'm not sure what you mean by flushing it with light oil.

 

[Laddies]

Re: Power trim losing pressure on 75 horse Mariner

You need a spanner to unscrew the top of the cyl. pull the ram out and on the rams pistion you will see the check valve use a spray can of oil and blow thru the valve to flush any debrie out.