89' Mercruiser 140 tilt/trim issue

[Cjpainten]

Everything was working properly except for the up solenoid which would click from time to time. Replaced both solenoids, took apart electric motor and cleaned it up, put everything back together and somehow overtightened the motor to the pump, crushing coupler in the process. Ordered a new coupler and took apart hydraulic pump to make sure everything was ok internally. Cleaned up hydraulic pump and put back together. Topped up system with 10w30 and put everything back together. Trim goes up perfectly, but when I attempt to lower it the electric motor runs but the unit does not lower. If I open up the relief valve on the pump the drive will slowly lower. The pump builds pressure to go up but not down. Does anyone have an idea where to look? When I had the internal pump apart I tested it and it worked in both directions.

 

[alldodge]

My guess is the valve body has been damaged, so you will need to test the hydraulic output pressure. Here is the manual which offers insight

http://www.boatfix.com/merc/servmanl/6/6a5r3.pdf

 

[alldodge]

My guess is the valve body has been damaged, so you will need to test the hydraulic output pressure. Here is the manual which offers insight

http://www.boatfix.com/merc/servmanl/6/6a5r3.pdf

 

[Cjpainten]

Thanks for the response and the PDF. That is a good one to have.

Got home today and took the pump/ reservoir assembly off the boat. Brought it to the bench and put the unit in a bucket with enough oil to submerge the intake and spun the pump using a drill. What I found was that when spun clockwise the right side which was responsible for the pressure to raise the outdrive was squirting oil like it should, but the left side when spun counterclockwise was not. I disassembled the pump unit once again and found everything to be intact and working properly. Next I took apart the intake port (had not done this before) and found my problem. The ball was stuck to the spring and had old oil caked around it. I took the spring out and cleaned it as well as freeing up the ball and reassembled. Connected the lines, filled up the reservoir and everything works again...

 

[alldodge]

Great to hear it was a easy fix. Thanks for coming back and closing the issue. Stick around, we need more DIY'ers

 

[Cjpainten]

Will do...

I have a few additional issues with this boat I just picked up and I'm sure I'll be needing some help as I will be fixing her up over the winter. I just don't like making new topics until I have ruled out the basics.

I'll do what I can to help out but at this point I am new to boats.

Thanks again for your help.