1982 140HP V4 Tilt Trim goes up only.

[wolferm73]

The tilt motor runs with both up and down switch on. But Motor moves up no problem, just won't move down, even though tilt motor is running.
Unless I loosen manual release screw. Tried filling and making it go up and release for down
a few times and still nothing. Will only still go up. Is there a sequence if it is a bleeding problem. I believe the fluid is full.
Just thinking is there a shuttle valve that could have a bad o-ring causing unit to go in only one direction, if so where & how is that fixed?

[Joe Reeves]

In the down mode, the engine normally drops due to gravity until it hits the trim range.

In the "down" mode... the engine isn't moving BUT are the trim rams pulling in?

If so, the steering/tilt pivot tube has become slightly rusted/corroded to a point whereas the retaining nuts have tightened up. Loosen one of the nuts a half turn of so and bang/knock the steering swivel back a forth a bit to loosen it up... then grease it.

Let us know if this cured the problem or if it's deeper.

[sodybread]

try with motor running.

[wolferm73]

If I loosing relief and let motor go down with gravity it stops at the trim rams. If left that way those rams will eventually go back in and motor is then fully down. The steering tilt pivot tube is fine. Steering itself has always been a little stiff with this motor but fine I pump new grease in every year and work it in moving motor left to right numerous times. Even with outboard running same.
Like I said the tilt motor runs fro both up and down, Only up does the outboard move. Only way to get motor down is by loosening relief. Other places said there is a shuttle valve that could be stuck located right under the tilt motor on port side. Unit is full of fluid. I tried tapping the shuttle valve which has not budged.

[wolferm73]

I have also considered taking the whole unit out. All bolts have been removed holding it in. but the big pin securing top of piston is not budging at all moved it maybe a 1/16 of an inch to get retaining clips out but have not been able to move since. Spraying blaster on it and gonna try freeze spray today. Any other thoughts on getting that pin free. If I can't get this unit working and do get it removed, how hard would it be to use it without tilt/trim. Is there some means of keeping motor in place while boat is moving being hydraulics are not present.

[Joe Reeves]

If by some chance you've trailered that rig with the engine tilted up BUT not locked in place, that allows the engine to sort of jump up and down which sets up the following condition. Let us know if this explanation cures your problem. My apologies for not mentioning it previously.

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(PTT Hydraulic Lockup)
(J. Reeves)

If the engine has been trailered without having both of the trim rams pulled in, or trailered without even having the engine being supported by the trailering support, it is possible for the PTT to encounter a hydraulic lock up. The slight up and down motion, when trailering allows over 1700 psi of oil pressure to build up on the wrong side of the oil pump. Since the oil pump cannot exceed that 1700 psi, the unit is effectively hydraulically locked into position (the elec motor runs and does nothing).

The proper method for trailering is to have the engine in a full tilt position and resting on the trailering support bracket, then have both trim rams pulled in to a point where the engine makes a jerking motion. At this point, immediately take your finger off of the PTT trim switch. Now, quickly and sharply, tap the PTT up button. This removes the vast majority of down hydraulic pressure but at the same time, the engine is solidly locked into position and cannot rock up and down.

(The Cure)
Have the engine in the up position and supported so that it cannot fall. Look straight at the PTT assy.... you will see what looks like a large slotted screw on the port (left) side of the PTT assy, but which is in fact a check valve. Remove that valve and what you find inside which is a shuttle valve, and a spring on each end of that shuttle valve.

After you've removed those items, look straight inside of that chamber. You'll be looking at the reverse side of another check valve. Look at the hole in the backside of the valve you removed. You will need a punch that will fit inside of that hole.

Now, place the punch inside of the hole in that check valve that is still in the unit, and tap it rather sharply with a hammer. It will take quite a rap but the idea is to unseat the valve to release the hydraulic pressure. Watch your eyes as when you do release the pressure, it will have a tendency to spray out somewhat.

After releasing the pressure, reassemble the shuttle valve, springs, and outer check valve. Fill the oil reservoir with PTT fluid, having the engine in the extreme full tilt position. That's it.
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