Leaking power trim cylinder

bmoebrc

Cadet
Joined
Jul 22, 2011
Messages
8
I have a power tilt and trim unit with a ram (cylinder) that is leaking. It is the older style Mercury external 2 ram unit on a 1980 70 hp. The leak is at the piston rod and the cylinder retainer. It occurs in both the up or down positions however it is not affecting the position of the motor when in the up position. I suspect that the slipper seal and piston are okay. My plan is to replace all of the o-rings except the slipper seal since I am not losing any motor positioning.

My question is, can I replace the o-rings without removing the piston from the liner by removing the bolt that attaches the rod and piston and leave the piston in the liner. I understand that re-installing the piston in the liner is difficult and may require a special tool.

I appreciate any input from anyone who may have expertise with these types of cylinders. Thanks for your help.

IMG_2168.jpgIMG_2172.jpg
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
27,826
Re: Leaking power trim cylinder

Yes, I was able to do that on my '77 PTT system, with the two external trim cylinders. Open the end of the cylinder and carefully pull the trim cylinder rod out. The steel liner should come out as well, with the piston still installed.. Now unbolt the piston from the trim cylinder rod and replace the oring in the cap.
 

bmoebrc

Cadet
Joined
Jul 22, 2011
Messages
8
Re: Leaking power trim cylinder

Thank you for your input. Based on the cut-a-way drawing that I have, I thought that may be the case. I just wanted to see if anyone actually was able to replace the o-rings without removing the piston before I started disassembling the cylinder. Thanks again.
 
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