50 HP Trim: motor works, outboard goes down not up

[chiliman77]

Hey, thanks for trying to help. I've searched for this, but can't seem to find anything helpful. From seeing the questions asked, let me see if I can describe this as best as I can...

Motor: 2001 Johnson 50 (J50VLSIB) white

Issue: The power trim does not push the outboard to the up position.
- The trim motor works both going up and down, and sounds normal.
- The outboard goes down under power trim. I think this may be because the load is assisting to push it down.
- The outboard does not go up under power trim. It does go up if I push the up button while lifting the motor.
- The outboard does not bleed down when in the up position, i.e. when it is up, it stays that way until I put it down
- The fluid reservoir appears to be full, i.e. oil leaks out the fill port when I take out the plug. The fluid is clean.
- There are no significant leaks (there is a drop of oil around the piston seal, but does not appear to be an issue)

I am not very familiar with hydraulic systems, but there could be air in the system? When I went to check the fluid level and removed the plug, as I was unthreading it, pressurized air was escaping. I think this could be the issue, but am not sure. Fluid did still drip out after completely removing the plug.

If I cycle the motor down and up and keep bleeding off the air in this manner, will that solve the problem? Won't there still be air (less and unpressurized, but still there) directly behind the fill plug?

Also, wouldn't the system be spongy with air in it? The outboard seems fairly solidly in place at whatever angle I leave it in.

Thanks for looking, if you have any suggestions or comments, I would appreciate it. If you need any more info, I can get it.

 

[boobie]

Re: 50 HP Trim: motor works, outboard goes down not up

The unit should be filled in the full tilt up position. If you're not doing that, try it and then cycle it up and down and recheck the level.

 

[chiliman77]

Re: 50 HP Trim: motor works, outboard goes down not up

When I checked it as mentioned above, it was in the full tilt up position. The boat was angled back slightly, but there was a stream of fluid coming out.

After cycling once the level appears the same, but when loosening the fill plug pressurized air escaped again. Does that mean there is just too much air in the system?

Thanks for the help.

 

[boobie]

Re: 50 HP Trim: motor works, outboard goes down not up

Is the manual release valve tight ??

 

[chiliman77]

Re: 50 HP Trim: motor works, outboard goes down not up

Yes. At least as much as I want to try to tighten it. Those things bother me, as I've twisted the head off one before.

However, if it was open, the motor wouldn't stay in the up position, would it? It would drop back down on its own....

 

[RRitt]

Re: 50 HP Trim: motor works, outboard goes down not up

You are right, not manual release because there is no drift down. Probably not low fluid because there is no bounce after assisted lift. Not check valve either because no drift down.

does it ever have difficulty changing direction?
If so, then I would suspect something in the shuttle and check valves.

if you push down on prop does it break open fairly easily?
If so then I would suspect something with pressure regulation, internal water damages, or bypass balls in piston

 

[chiliman77]

Re: 50 HP Trim: motor works, outboard goes down not up

It does not have difficulty changing direction. I'll have to check, but I'm pretty sure that if I push on the prop, nothing really happens.

I doubt there is water inside, as the unit is fairly clean. Also, the fluid that came out when I checked the level was clear and not emulsified.

Is the pressurized air I am seeing a normal thing upon release of the fill plug? I would think that if I was getting pressurized air in there, there has to be some air in the system somewhere. However, that is just my gut, I don't know too much about these. I suppose maybe it could just be pressurized air from the fluid returning to the reservoir from the top of the piston after it was raised?

I was thinking of trying to take the unit out to see how it worked under no load. However, I'm not quite sure how to get the top pin out that connects the ram to the outboard. It appears to be aluminum, and there is no access to push it out from the port side. The only thing it has is a 5/16 internal thread on the starboard side, but the pin is fairly well caught up in there from corrosion/etc as these things usually are. What is intended to be used on that? A slide hammer? I don't understand why they do these things sometimes....

Thanks for the help.

 

[RRitt]

Re: 50 HP Trim: motor works, outboard goes down not up

the reservior has positive pressure when the system is lowered and negative pressure when raised. This is because the piston shaft displaces oil as it is retracted.

This particular system has a real problem with trapped air. If an airbubble is trapped underneath the piston from shipping or rebuilding, then it can later escape. This can cause positive reservoir pressure on a fully raised system. With the system upright, cycle up/down, fill, go eat lunch. Repeat until all air bubbles have had plenty of time to float up out of the pump gearcase. Usually only once or twice, but it can tkae 10-15-more minutes for the bubbles to float free from filter screen.

Has the system been disassembled? If so, then the small ball valve under gearcase may have been put in wrong. unless it's just a trapped air bubble in gearcase then your problem is out of the mainstream. no bleed down, can't push drop prop by hand, no troubles shifting directions .... all the usual suspects are eliminated.

 

[chiliman77]

Re: 50 HP Trim: motor works, outboard goes down not up

Ok, well here's an update: After cycling it while troubleshooting the other day, it has been sitting. I went out and cycled it down and up today, because I wanted to open the cap and see if I had negative or positive pressure (i'll be honest, hadn't even considered it would be negative). Like RRitt said, it did have negative pressure when raised. Also, it went up by itself (it seemed a bit slow, and petered out towards the top of the cycle, where I had to assist it the rest of the way). So, I cycled it again, and it seemed a little bit better. It is still struggling at the top of the cycle, but maybe I just need to keep at the cycles and there actually is some air in it.

 

[boobie]

Re: 50 HP Trim: motor works, outboard goes down not up

Add some fluid to it when it's in the full up position if it will take it. And try it again.