mystery trim problem

[smokeonthewater]

leaking seal on cylinder.... I bet that if you trim full down and hold for a few seconds you will see evidence of the leak..... rainbow sheen on water or oil spots in driveway

I had a trim leak this past july which turned out to be a cracked trim hose from transom to drive which only leaked when pressure was built up from down trim or boat in reverse in water

[macojoe]

my bad!! I use to have a Yamaha that the screw would come lose on one of the trim cylinder and leak when in the water, took a bit to track that down?

[steplift20]

so in the fully down position thats where the most pressure is?

[steplift20]

just added oil again about 2 0z still see no leak what i would like to do is replace the whole bracket with the trim assembly and keep the motor
can i get one and how hard would it be to do that

[phatdaddy]

what kind of motor & year? if an ob, older mercs, you have to take one of the side brackets off, omc, you should be able to get to under the ob.

[macojoe]

I am telling you when my old Yamaha was doing that it was the cover coming lose on the piston, I had to keep tightening it, then the O ring on that same cover went, the oil was washed away in the water so you could never see the oil leaking.
I found it by lifting the motor up and down in the water , the oil made a rainbow, I just kept looking till i found it.

[steplift20]

its a 1988 150 mercury out board
i keep it on a trailer so it should be easy to find but i cant see no oil anywhere
one of lifes mysterys and a happy new year to all my freinds on this site and thanks for all the helpful advice you given me

[smokeonthewater]

Originally Posted by steplift20

so in the fully down position thats where the most pressure is?

well when trimming up, the pressure is under the piston but trimming down it is on top of the piston and pushing against the pop of the cylinder... so down is when it is most likely to leak externally.

[steplift20]

i dont have my boat by my house its by my sons house , so how do you tighten it and what tools do i need to check it

[macojoe]

At first I used a punch and hammer, then I found the spanner wrench I had for my 4 1/2 grinder fit it perfect!
Just use the punch and hammer to see if you get it to turn some, if its tight still don't right it off, cause it can be the o ring also.