MC-1 Trim Pump issue.

[ScottinAZ]

ok, we are working on a 1980 vintage 120hp MC-1 trim pump. Metal reservoir with external control valve.

I have function in trim-up but nothing in trim down. I am bleeding the lines at the moment due to it running dry over the previous 9 years since it had last operated. Reverse lockout and trim cylinders both have been rebuilt, as they were leaking. Buttons work good, solenoid (single) works OK (new one on order).

Took the pump out, and the plastic line (down) fitting was loose in the valve body. Removed this, and the check ball was above the spring, and against the fitting, closing it off to any fluid flow.

My manual (mercury manual #4) does not show an exploded of the valve body, just as an assembly. Normally this would mean its not serviceable, however we have a bunch of smart folks here that dont take no for an answer. What I need to know is this, what is the proper assembly order for the check valve on the down side of the trim? I have a light duty spring, a small washer, a heavy duty spring and the check ball. All of which are under the pipe threaded fitting.

 

[kenny nunez]

I sent you a private message regarding the pump

 

[ScottinAZ]

ok, did a bit of trial and error to figure it out. Check ball goes in first, followed by small spring, washer and big spring with the fitting holding it all in place. System bled and working 5.0 according to specs.

saved me replacing the whole valve assy.... not expensive, but time wasted waiting for parts when an idiot PO put it together backwards probably due to a leaking reverse lockout. New o-rings fixed that right up..... Hooray, I now have up and down trim. Just need to top off the reservoir and finish bleeding it.