Power trim stuck

[KA23]

Went to use the boat today and the outdrive was stuck in the towing position. The motor whined with good power but the drive wouldn't budge. Almost like it was tied up. Fluid looked good to me. I tried everything, using the tilt switch, trailer switch, putting some pressure on the drive etc. I put it back on the trailer and parked it. It's a 2000 5.0 Mercruiser I/O. Any ideas?

 

[Bt Doctur]

how long was it stored in the full up position and did you tap the down to release the pressure from full up?

 

[KA23]

Stored only two weeks. I tried using the trigger for the trim, both up and down to try relieve any pressure. The trailer button will only lower the drive but wouldn't today. I'm baffled. It has to be something simple. I've been raising and lowering out drives for 15 plus years.

 

[Bt Doctur]

the "trailer button" ONLY RAISES THE DRIVE, the down trim button lowers it.If the trailer button is lowering it ,you have the pump lines reversed

 

[KA23]

Yep I know that. I can't tell if trim button is working because the drive is all the way up.

 

[UncleWillie]

When you cycle it up and down, does the drive move ANYTHING at All? Even an 1/8"?
Do both cylinders move the same amount, and in the same direction?

 

[KA23]

UncleWillie, it didn't come close to moving at all. Completely frozen. I didn't want to work it too much for fear of burning up the pump. I even tried both batteries thinking it wasn't getting enough juice. Lots of power but zero movement. I've never had this happen in all my years owning an I/O.

 

[Bt Doctur]

Is the oil in the pump clean, not milky?
try reversing the hyd lines at the pump. the 2000psi might get it moving downward , once its free, reverse the lines back to normal

 

[Bondo]

Ayuh,..... Have a "Heavy" friend jump on the drive, while the pump is run down,......

'n never leave the drive in the full up position, without bumpin' the down switch a couple of taps,....

 

[UncleWillie]

If you hear the pump straining hard but nothing is moving, The UP Shuttle in the pump may be stuck due to pressure behind it from the major temperature changes.
If you loosen both hydraulic lines from one of the cylinders, both cylinders should go slack. Be prepared for the Oil leak!
If the drive starts to drop under its own weight, you will know that there is nothing wrong with the cylinders.
Try to cycle it again if it moves.

Never leave the drive stored in the UP position.

 

[KA23]

UncleWillie, I will try that. That would make sense as temperatures have skyrocketed here in the NW into the upper 80's. I hope you are right and yes, lesson learned on storing the drive all the way up. UGH!

 

[UncleWillie]

The number one reason not to leave the Drive in the UP position is that the Bellows are stretch to near their limits.
It may be just the reason they need to finally fail.

As Bondo mentioned, it is not a bad idea to move the cylinders just Off the limit stops.
The UP pressure relief valve especially, does not open until the pressure tops 3000 psi.
Once you hit the limit and hear the pump straining, give it a 10th of a second in the other direction to relieve the pressure.

 

[KA23]

Fixed it. Thanks for all your advice. I added a little more fluid, opened the lines to one of the cylinders and reattached them! Bam, it works great now. I cycled it up and down about 10 times and she's good! Thanks!