1970 mercruiser 165 drive tilt trim sender hydraulic issue

[Yogi/Captbob]

Happy 4th to all! Please stay safe-- I have a 1970 John Almand. The outdrive travels up and down fine. The tilt trim sender slave cylinder will not travel to the up (right) position. Cannot find 165 drive hydraulic circuit explanation and diagram. Gauge and sender checked and working. Piston/ sender actuating rod free with both lines disconnected, and drives to down position when in circuit and 'burped'. Both lines have good flow with respective control actuation. Slave cylinder piston/ sender actuator will not travel to up unless down feed is disconnected. Down feed line routed to bottom of pump. Up feed to slave cylinder routed through what appears to be switching mechanism connected to shift linkage. Again, the drive does raise and lower. Is there a separate check valve or solenoid circuit for sender cylinder down line in return mode? Have not been able to find anyone with experience with the older hydraulic sender system and this particular issue isn't covered in my Merc. manual. Thanks in advance for any help!

 

[alldodge]

Howdy

The other piece your talking about should be the reverse lock valve. The valve keeps the drive from going up when in reverse.

Here is one which should cover your system
http://web.cemr.wvu.edu/~mathews/boa...20Eighteen.PDF

Mark Mark72/233 has just put two of them back together and may have some pointers

 

[johnkom]

I had a similar problem on my 1972 165. The piston/sender actuating rod has a linear rheostat that sends the signal to the gauge. On mine I carefully dissembled the rheostat and cleaned with contact cleaner. Problem solved.

JK

 

[Bzcruzin]

I had a similar problem on my 1972 165. The piston/sender actuating rod has a linear rheostat that sends the signal to the gauge. On mine I carefully dissembled the rheostat and cleaned with contact cleaner. Problem solved.

JK

Hi,I’m new on this site.This is the best information found on the 1970 165 trim sender.I have the issue of not knowing where the wires go on the hydraulic piston/electric sender unit.I bought the boat and the wires were just hanging not connected to anything.My gimbal tilt sensor wire are not connected but are toast.If any one has information on the wiring would be a great help.Thank you BZ