Power Tilt/Trim only working in one direction

I have a 1991 75HP Mercury with power Tilt/Trim.<br /><br />I have not used it for a few months and today the Power Tilt would not move upwards (but down is fine). The motor humms but no movement. I swapped the solenoids but no difference. The fluid is at the correct level and the manual override screw is tight. <br />I turned the manual override screw back one-to-two turns and the motor would then go up slowly but would not go down.<br />Is this likely to be a worn valve or o-rings or possibly air in the system?

Re: Power Tilt/Trim only working in one direction

Welcome to iboats. <br /><br />Most likely a broken lever inside the pump. That was a common problem back then. I'd guess that at least 3/4 of those units have failed by now. They were pretty crappy. Parts won't be available cuz Merc told the manufacturer to pound salt, so they stopped making replacement parts.<br /><br />On the top of the pump (inside the reservior) is a lever that rides on the shoulders of two valves. Either it slipped out of place, the lever broke, or the pivot pin sheared. I've had good luck replacing the pin with an appropriately sized nail trimmed to size. Otherwise the only fix Merc offers is a new trim unit at somewhere around a $grand.

Re: Power Tilt/Trim only working in one direction

Thanks. It sounds like a job for the local service agent. I'll let you know the results.