Tilt/Trim losing pressure

[foots]

Pertinent information... 1988 Johnson 40hp. Model # J40TLCCS.

Problem... hydraulics SLOWLY let the engine settle all the way down against the mounting assembly. It will trim up and down with no problem at all. Once it stops it will very slowly start to drop until it can't settle any more.

There is no external leaking anywhere on the assembly.

I checked the manual relief valve and it appears to be ok. The rubber insert in the tip of the screw appears fine.

Seems like it may be time to replace to O-rings but I don't want to be overlooking something obvious, not being familiar with this particular hydraulic setup.

Thank in advance for any help/advice.

 

[boobie]

You could try a different manual relief valve and see what happens.

 

[jakedaawg]

I agree with Boobie, least expensive place to start is replacing manual valve assy and related o-rings. This is assuming fluid is full. If that doesn't solve it its easier to live with it useing the manual flip lock thingy than it is to find the leaky check ball in the unit.

 

[James R]

I agree on the manual release but it only takes a tiny bit of dirt in the system to cause a no seal situation. If you can remove the manual valve do so and operate the tilt trim just a couple of quick shots. Oil will shoot out so put the motor where it wont make a mess. Making sure that the valve is clean refit it. With the valve released, manually raise the motor to the fully up position and set the latch. Close the valve. Refill the reservoir with fluid and refit the fill cap. Release the latch and operate the tilt trim up and down over the full stroke a few times to drive the air out. Put the motor back to the fully up position and remove the fill plug Top up the fluid and repeat the purging process. The air should be out after two or three operations.This is the cheapest thing I know to do and it sometimes does the trick.

 

[foots]

Thanks a lot for the suggestions guys. I will follow the advice given when I return home from work in 23 days or so. I appreciate the responses.