Trim Pump

[BuilderFL]

Merc 200HP 1980 - I have noticed that my trim pump (the square motor type) has been decreasing in pumping pressure gradually over the last few weeks. It’s now to the point that although it trims both up & down when I’m not moving, underway it does not work at all. Oil level is good and all air from lines was bleeded. Any suggestion as to how to troubleshoot the pump? :head: Thanks

[THEFERMANATOR]

I take it this is the pump mounted inside of the boat with hoses run to the engine. If so you probably have a checkball issue inside the pump. Is it dragging at all? Does the fluid look milky? If it is the remote pump, it is the same pump that all of the MERCRUISER guys have for the most part.

[turbinedoctor]

Can you tell if the pump motor is even running when you are under power. I have an 84 pump which is mounted inside the bilge that I had to replace the brushs. It quit all at once but the brushs were worn down to the copper wire that was attached to them.

http://www.mercruiserparts.com/

They will probley have the parts you need.
:beer:

[BuilderFL]

Yes, the pump is mounted inside the boat with two hoses to the motor. The fluid is not milky and I'm not sure what you mean by dragging except that it does not have the power to lift the motor under the extreme pressure while cruising. Keep in mind that the pump is working otherwise. Worn out brushes? I will check them today. Checkball, not sure what they are but will look them up. Thanks!

[THEFERMANATOR]

The checkballs are monuted inside of the pump in the pick-up tubes for the pump. Does the pump sound like it is running slower than normal. The SEA RAY I redid last year wasn't lifting the leg up properly so I pulled the pump apart and went through the pump. The brush's in it were sticking and not letting power to armeture under load. Simply pulled them out of there holders and sanded with a little 320 to clean them up. And the actual pump driveshaft that drove the main pump gear was galled. So I sanded the shaft and re-assembled, worked like new afterwards.

[BuilderFL]

What you're saying about the brushes sticking and not allowing all the power to the armature makes a lot of sense. I will try it this weekend - Thanks FERM :clap:

By the way, I picked up a used one on e-bay for $20 (+18 shipping) figure it's worth it if only for the parts. The seller says it's working good and shipped it today.