Just finished a complete bellows replacement and water pump replacement of my 1970 Mercruiser 165 outdrive. No problems with any of that. Hooked up my trim cylinders. Up is no problem and they push up with good force. Down is the issue. The drive trims down, but stops and inch short of full down (pump is running, but makes sound similar to when trimming up and it hits its limit) If you go up all the way up again and come back down, it stops about 2+ inches shorts of full down. This keeps on this way until it only goes down a little before it stops. I can get the drive to trim all the way down when I open the down port hydraulic line fitting on a cylinder and to let fluid drain and relieve the pressure.
1. Kept pump resevoir with enough fluid. Never let it run dry.
2. Bled pump up and down side in accordance with service manual #1 pages 7A-16 and 17 for Large Resevoir Black Pump.
3. Nothing is binding in drive. Cylinders do the same "not all the way in" as described above, even when not connected to the rear mounting pin.
4. No leaks in the hydraulic system noted anywhere.
5. System worked before with no problems until after I completed the bellows job. Trim cycliders were extended and tied pointing up while I worked on the other parts, about a week.
Frustrated and running out of troubleshooting ideas...
1. Kept pump resevoir with enough fluid. Never let it run dry.
2. Bled pump up and down side in accordance with service manual #1 pages 7A-16 and 17 for Large Resevoir Black Pump.
3. Nothing is binding in drive. Cylinders do the same "not all the way in" as described above, even when not connected to the rear mounting pin.
4. No leaks in the hydraulic system noted anywhere.
5. System worked before with no problems until after I completed the bellows job. Trim cycliders were extended and tied pointing up while I worked on the other parts, about a week.
Frustrated and running out of troubleshooting ideas...
