1975 Trim Pump

After rebuilding the pump to replace 2 busted o rings, I have now lost my shop manual. I have reinstalled the pump and ready to fill the reservoir. I am sure that I need to bleed the air out of the lines. Are there bleeder valves or screws and where are they? Whats the procedure?

1975 Mercury 850 85 HP This link is the exact pump:
http://www.crowleymarine.com/mercury_parts/8504/10.cfm

Thanks

Re: 1975 Trim Pump

The pump is self bleeding. The trim cylinders are not. If you need to bleed the trim cylinders, there are two bleed screws on each cylinder. You may bleed the down circuit by opening the bleed screw on top of each cylinder, next to the zerc. Open one screw and run the motor in the down direction. When you see only oil (no air bubbles) shoot out of the trim cylinder, it is bled. Replace the bleed screw and repeat with the other cylinder. To bleed the up circuit, you need to remove the cylinders from their mounts and face the bleed screw next to the two hydraulic lines up. Remove one screw and run the pump in the up direction until you see only oil emerge. Replace screw and bleed the other cylinder. Refill the pump with SAE 5W-30 motor oil or ATF, whatever you already have in there.

Re: 1975 Trim Pump

I was afraid I would have to remove the cylinders. Thanks Chris!!!:redface:

Re: 1975 Trim Pump

Got the cylinders bled but now my "up" button doesn't work at all no noise from the pump motor. I'm pretty sure I got it all wired up the right way.

Is there a fuse or relay somewhere that could have been blown during instalation?

Frustrated, I got the leaks in the pump fixed now this. PLEASE HELP.

Re: 1975 Trim Pump

The Up circuit on that PTT unit has a solenoid. Perhaps it is bad. In additon, inside the motor is a bi-metal overload device. it will open if the motor pulls too much current. Sometimes dirt will get in between the points and cause the overload to stay open. An ohmmeter from the PTT motor blue wire to the black wire will confirm whether the overload is open. Low resistance, and the motor and overload are good. Open circuit says the motor or overload are bad.

Re: 1975 Trim Pump

Thanks Chris I am heading out to test it now.

Re: 1975 Trim Pump

So tested everything last night(even pulled out the manual and ran the troublesoot sequence) nothing seemed wrong, all tested good, no open circuit, gave up for the night.

Went out today to test one more time before giving up and calling mechanic and the darn thing was working just fine. So I am way confused. But it is working fine now.

Gonna winterize and put away for a few months, well see what we get in spring.

Chris, are the things known to be haunted???? It is close to halloween.

Re: 1975 Trim Pump

Yeah, things are haunted. Even if it is not close to Halloween. Sometimes you try everything you know to fix something, without success. After you give up, without fixing anything, sometimes the machinery just gets better! I am at a loss as to why....