Force 120hp tilt n trim question?

[pwilke]

I have a complete tilt unit that came with my boat, owner was going to have it switched out due to the other unit having a leak down problem. that never happened. I am putting power to this unit and no movement at all up or down, I thought it might have had air in it so I took out the front and rear plugs and drained it, then refilled it, I have checked the fluid level periodically so it shouldn't be low on fluid. When I power it you can hear the pump motor kick in in the up or down position, (doing this by just switching pos & neg connections, it sound good spins good but I still am not getting one movement out of the lift unit. It does have pressure on it but I can still pull it up by hand and lower it by hand.
Same unit as my 1990 Force 120hp but I'm sure it would work on a lot of motors. Has the 3 lines going into the side and the one line that connects to the bottom on the pump. Trim ram in the middle and 2 lift cylinders. I don't know what to think. Any suggestions? thank you

 

[RRitt]

Re: Force 120hp tilt n trim question?

I assume 1990 means Prestolite. If, by some chance you have an Eaton, then it is probably the cheap Mercury fluid has eaten up the orings from inside out and system needs major overhaul.

If prestolite ..

1) system doesn't work upside down
2) rusted out tilt piston (needs be replaced)
3) missing missing pump shuttle
4) blown out check valves (need to be replaced)

could be other stuff but these are most likely culprits. Start off by rebuilding all three rams. That will confirm good tilt piston and eliminate possibility of cheap ATF ruining your rubber seals. If problem persists then it is pump for sure. If it is pump then you can't fix it at home except to take check valves out of a working unit. Once they stretch you can't reuse them.

 

[pwilke]

Re: Force 120hp tilt n trim question?

Yes, its the prestolite unit. thanks