Can you rebuild an external mercury trim pump

[rockymercury]

I have an 81 bass tracker with the external dual cylinder trim pump mounted on the inside of the transom. Is there a rebuild kit for the pump part of the unit. The unit works fine it goes up and it goes down but it does not stay up. AT all it immediately bleeds down as soon as you let off the switch to raise it. on the other hand it can't be the cylinders leaking back because i can't pick the motor up from the down position to the up position without twisting the manual release. Can i rebuild the pump? IE: new rubber sealsgasketssprings,, and ball bearings or is it a lost cause. Where in the trim pump should i look to see where it is allowing the bypass of the fluid. Thanks for any help i can get man on a low budget in desperate money saving tips Thanks Rocky

 

[Chris1956]

Re: Can you rebuild an external mercury trim pump

rocky, It is likely that you have a bad teflon piston seal in one of the trim cylinders. There are rebuild kits avail ($40), but you need a special tool to install the seal. You can isolate it by removing one of the trim cylinders and plugging the lines. If it still leaks down, the other cylinder is bad.

 

[rockymercury]

Re: Can you rebuild an external mercury trim pump

I think i have ruled out the cylinder seals. My thought is that it will leak both ways. I tried picking the motor up when it was all the way down and it wouldn't budge. I was straining to pick up and it didn't move. An i right or will it hold pressure one way and not the other way. It locks in the down position but in the up position it don't have a chance it falls immediately as if the fluid was running back without anything stopping it. I will try the taking off one cylinder and testing each seperately. How would i go about blocking off the lines of the other cylinder. Is there a fitting that i can put on it to block it off