1973 Merc 850 trim/tilt

[cak083079]

I have a '73 850 thunderbolt with power Tilt/Trim, the type with 1 solenoid and release valve. I have verified the soleniod functions, filled it with oil and followed the repair manual instructions for bleeding the system, but it still will not function. I hear the motor turning in the pump, but I am thinking the seals are bad in the pump.

can anyone help me out with this problem?

Thanks!

 

[Moody Blue]

Re: 1973 Merc 850 trim/tilt

I would pull a line off one of the cylinders and operate the pump. You could then determine if the pump is working or just the motor.

 

[Chris1956]

Re: 1973 Merc 850 trim/tilt

Did oil shoot out when you were bleeding the cylinders? It should have. How did you bleed it?

 

[cak083079]

Re: 1973 Merc 850 trim/tilt

oil shot out of the bleeder screws about 3 to 4 inches. I'll try the hydraulic line test sometime this week.

Thanks for your help!

 

[Chris1956]

Re: 1973 Merc 850 trim/tilt

If oil shot out of the bleed screws, you have already done the hydraulic test. The up hydraulic circuit must be bled with the bleed screw facint up. You therefore need to remove the cylinder and turn it over. I reinsert the top mounting bolt, and the hoses cause it to be in the correct positon, facing the heavens.

Run the pump in the up direction until there are no more air bubbles. Reinsert bleed screw and repeat with the other cylinder. Now reinstall the cylinders and remove a down bleed screw on the top of the trim cylinder. Run the pump in the down direction until no more air comes out. Reinstall the bleed screw, and repeat with the other one.

if it still doesn't work it may be the control valve on the pump assembly. Don't forget to fill the resevoir with 5W-20 or ATF, whatever is already in there.