DesertRage

iTrader: (2)

This sounds like good advise. Bill, Lets us know what you find out.

Rage

Thanks for the thoughtfull brainstorming and suggestions.

Yesterday's testing with both cylinders disconnected from the drive and therefore operating at no load with the drive (and sensors) at the full down position and now static would seem to take the electrics mostly out of it. Also the pump would still randomly labor at different levels indicating load/strain on the fluid pump as the cylinders were trimmed out or in. The cylinders took turns sticking, shuddering or conversly running smoothly. Sometimes both cylinders would just stop as the pump would stall completely. Sometimes on these occasions if I would release the trim button and immediately reapply everything started again to work correct....only briefly. The sounds the trim motor made during this testing versus the movement, or lack there of, was like the fluid resistance was overloading the pump motor as apposed to intermitant electrical connection problems.

I would like to hear about the potential hydraulic reasons and or fixes for my trim issue that you may be aware of. I have so far heard that dirty fluid could be the cause and a simple fluid change may fix the problem. Also suggested was that the trim cylinder piston seal (seals?) seperating the up pressure side from the down pressure side of the cylinder could be bad/leaking. Corrosion build up between the of the aluminum trim cylinder body and stainless steel ram shaft (I checked mine and clear). Your thoughts experience versus these or other causes?

DesertRage

iTrader: (2)

After your done prop testing for the year I would pull one ram completely from the boat and disconnect the hydraulic lines. Then manually cycle the ram, feeling for resistence inside the ram. If something sticks, pull the endcap and remove the guts for inspection. They come apart really easy. After the anodes are removed you will need an adjustable spanner wrench with two .250 dia dowel pins.

Rage

Good idea. I will do that when I go to remove the trim cylinders and pump this weekend to take back home for inspection and repair this winter

lookinforboats

just a side note - the corrosion on the end caps CANT be seen from the outside. They have to be removed to check/repair. JD

4bus

iTrader: (4)

Rage- Just a thought, have you cleaned all conections and changed the fuses? You may have a voltage drop issue due to a bad connection. Try operating with a volt meter on the pump and see what you have when it stalls and studders.

Rage

Good idea.

Rage

I disassembled everything on the power trim hydraulics (only). There was about an 1/8" layer of tiny black dust like particles in the reservoir. Then I found larger ~1/16" particles in various places in the trim pump manifold passages where there should not have been anything but fluid. When I evacuated fluid from the cylinders those same larger black particles came out. There is a black 1/2" thick crescent shaped plastic spacer that snaps on to the trim cylinder ram shaft. Well one cylinder had one and the other one did not except for that portion that was crammed into the three pressure relief check valves in the piston. Apparently the one plastic spacer completely disintegrated and contaminated everything with its residue. The seals all look excellent. The pump's two fluid hose connection fittings have a fine mesh screen welded/brazed to the fitting. The one fitting's screen was still good but the other screen had apparently been blown off by the fluid pressure against the screen when it was plugged with the plastic residue. That screen was still attached on one corner. That is how the residue got into the trim pump manifold.