All right, where does my power trim oil disappear?

[John C in PA]

Every Spring I have to add about a half pint of trim oil to bring the level to the bottom of the threads. (Yes, the drive is in full up position ). The hoses don't leak outside or inside the bilge. No leaks on the garage floor. The cylinders don't seep or leak. This is a Cobra drive. Any ideas?

John C in PA

[MOP]

John it may only leak under pressure, get a buddy to put his full weight on the drive then cycle it a few times. Nothing in the bilge it should be a fitting or ram outside.

Phil

[John C in PA]

Phil, my thinking was that since the oil is under pressure (how much?) when the drive is down, that the oil would leak out when in the garage (with the drive down) for the past 5 months. FWIW: when I loosened the fill plug there still was a little pressure behind it.

John C

[MOP]

There is no pressure in the unit with the drive down, a little pop of air when the cap is removed is pretty normal.

Phil

[John C in PA]

According to the manual, you check the trim oil level with the drive full up to relieve the pressure. Doesn't that mean the oil is under pressure when down? Or is the pressure fairly low in both cases?

John C

[MOP]

There is no pressure within the pump when not running, the pressure is in the lines and rams. These pump reverse rotation to provide the up/down, the pressure is held by the pop it valve for each circuit. Try what I said in my first post that should show a dampening of the trim rods if they are leaking, there is very little force in the static up position. The major force is underway when trimmed, you need a fair amount of weight on the drive when on land to show any leakage.

[John C in PA]

I'll give it a try Phil. I'm just surprised there are no residual signs of leakage even around the seals. Not a big deal in any case.

John C