1992 OMC Cobra tilt/trim cylinder rebuild

In trying to find if my old 92 Reinell V8 with OMC cobra was having Hydraulic seal problems in either the Tilt/Trim pump or the cylinders as the trim will not hold position, and in the full up position it drifts down in about an hour. So I thought that due to it's age I would just rebuild the cylinders first. Anyone here done that, and where can I find the proper spanner for removing the end cap, and the other dohicky tool for using in the vise that my seloc manual talks about. Rather than spend over 400 large on a new pump, I thought I would eliminate the cheaper stuff first. And due to its age, and what the repair diagnostic charts says, this seems a logical choice to do first. Also, is it true that if the pumps manual relief valve "O" rings are worn, that this can cause this drifting problem as well? And no....I do not have any external oil leaks, I never run low on hydraulic oil. Thanks in advance for the advice.

Rick

Pumps are cheap and plentiful on Fleabay. I have like 3 spares all work and none paid more than $50.

Yes pumps are plentiful on Ebay, and most of them are probably in worst condition than the one I have,"if" indeed anything is wrong with mine. I have done lots of wrenching, bleeding on stuff, and torque farting, but I ain't rebuilt a hydraulic pump valve assembly before, and am not real sure I want to, since my manual says it is for a skilled tech. I just have my shade tree license, and don't want to really go beyond that to a great extent; and I'm cheap..... and just a shade lazy, besides Arthritis is messing with my fingers and those valve parts are rather small. But I will rebuild my cylinders, and was wondering if anyone had any special advise, and where can I buy the end cap spanner for these cylinders. Rick