Need help to diagnos hydraulic tilt/trim problem.

Hello

I have an old early 80's Mariner 150hp outboard (serial #6455538) on a same era Invader ski boat. For the last few times it has been hard to get it to trim up - would take a long time. This weekend it finally died - wouldn't trim up at all. Finally out of the water we unhooked the hoses from the motor to see what was happening. When the trim down button is pushed it pumps out oil at least fairly forcefully. Trim up pumps nothing - can hear the motor run though.

What can I do to further diagnos the problem? If it was the celenoid it wouldn't have had the slow death, would it? - if it is the pump why would it pump one way but not the other?

I am hoping for a "cheap" fix. I found a place in the US that will ship me a motor and pump assembly for $470 US - as that will turn out to be around $650-700 by the time it gets to me in Alberta, I'm not likely willing to spend good cash on an old tub.

If a "cheap" fix isn't possible could I go farmer on it and rig up a non marine hydralic pump? - forgetting about all the finer tilt/trim stuff and use it just to lift the motor out of the water to load it on the trailer?

Thanks much for the help.
Carso

Cheap fix is to check your connections, if there is corrosion it would affect the trim. There is an "up" solonoid and a "down", though, changing the "up" is cheaper that a new hyrdolic unit.

Celenoids would be a good bet. I finally got off a little cap that I thought was the bleed - turns out this is the fill - I had been trying to fill though a hole just below this - don't know what the hole is that comes out perpendicular to the pump is. Anyways I filled, trimed/tilted and refilled about a dozen times. After it seemed to take no more I screwed the lid back on and it actually seems to work. At least I am going to keep my fingers crossed. My question now is could I have overfilled it? or should it be right at the top?
Thanks for your time.

All of my books say to fill to the bottom of the threads of the fill screw.

Fill from the bottom until it comes out the top, the "vent" hole. My understanding is the oil needs room to expand.

I read something about making sure to fill it when the motor is in the down position otherwise if you fill it when it is up you can overfill?? Anyone heard of this?
Thanks much.