Inboard/Outboard will trim up, but not down?

[pappacherry]

I have a 1975 Slickcraft with an 888 Mercruiser outdrive. Outdrive will trim up, but it will not trim down. When i press the button you can hear the motor trimming it up and the ourdrive trims up, but it won't trim down and I can still hear the motor for the trim.
All the trim hoses look good. I think I might have made the mistake of leaving it trimmed up over the winter.
Anyone know what the problem might be?
Thanks!

 

[Bondo]

Re: Inboard/Outboard will trim up, but not down?

Ayuh,.... It's Stuck.....

Have a Very Large friend Jump on the drive, as the Down button is pushed,.....
Then give it a Good Grease Job....

When you run the drive All the way Up,+ the motor labors abit, so you know it's All the way Up,..??..
You should tap the Down button a couple of times to relieve the over-pressure against the system.......

Btw,.... Welcome Aboard....

 

[Coors]

Re: Inboard/Outboard will trim up, but not down?

Too many Bondo s....
Computer back? and it died why?

 

[Bondo]

Re: Inboard/Outboard will trim up, but not down?

and it died why?

Huuhhhhhh,.... Downloading,+ Saving some Books I found online,........

Big Big Books.....

Sure am Glad I burnt'em onto DVDs.........

 

[pappacherry]

Re: Inboard/Outboard will trim up, but not down?

I actually undid a trim line and drained the trim fluid to get the outdrive all the way down. I refilled it and it will go up, but not down.
It will actually will go up a little instead of down when I try to trim down.

 

[Bondo]

Re: Inboard/Outboard will trim up, but not down?

Ayuh,....
In that case,...
Are the Lines back on, Right,..??

I suspect the Reverse-Lock Valve used on those old drives is probably the culpert,......

 

[pappacherry]

Re: Inboard/Outboard will trim up, but not down?

Yes, they should be on right. left hooks up to left right to the right.

 

[pappacherry]

Re: Inboard/Outboard will trim up, but not down?

HELP! Anyone have any advice? I bought a good working pump and still I have the problem. I then bought a new solenoid. Still won't go down. I unhooked the lines and tested if oil came out and oil spurts out fine. My only thoughts that can be bad are the outside pistons/shocks? HELP!

 

[Don S]

Re: Inboard/Outboard will trim up, but not down?

The tirim pumps have a high pressure side and a low press, side High is up low is down.If the cylinders are corroded inside and binding at the rod seal, then the pump doesn't have enough pressure on the downside to overcome the corrosion. Did having someone stand on the drive help? You never answered that.

 

[pappacherry]

Re: Inboard/Outboard will trim up, but not down?

I was thinking maybe that is what happend. Especially because it sat all winter in the up position. Yes, I tried standing on it. I am thinking 180lbs of jumping up and down would be enough. Also, when I unhooked the lines and freed up the outdrive, I sprayed wd40 on the rods and moved the outdrive up and down manually.

.

 

[Don S]

Re: Inboard/Outboard will trim up, but not down?

Do you hav an OEM Service manual??????

 

[pappacherry]

Re: Inboard/Outboard will trim up, but not down?

Yes, but it doesn't have anything specific on the trim pump. The tilt/trim system is simple and not complex. I was hoping that this was a common problem and would be an easy fix, but I guess I was wrong.

 

[Bondo]

Re: Inboard/Outboard will trim up, but not down?

Ayuh,....

2 things come to mind,.....

The Valving in the pump can take a set when left it the FULL Up position,....
And,...
Corrosion around the End-Caps of the cylinders tend to corrode,+ Bind....

 

[Don S]

Re: Inboard/Outboard will trim up, but not down?

Do you hav an OEM Service manual??????

Yes, but it doesn't have anything specific on the trim pump.

Look at section 7A, the trim system (pump and cylinders) is all it's about.

 

[QUEENCITYMS521]

Inboard gas leak

Inboard gas leak

You have a private message. See upper right by your name.

 

[pappacherry]

Re: Inboard/Outboard will trim up, but not down?

Ok, so finally after buying a different trim pump, new solenoid, new hydraulic hose. It was one of the trim cylinders. Should have checked them first. Left one was ok, but the right ones insides were blown to smitherines. Springs all fallen apart and broken. Thanks for the help guys. Many headaches, but I sure learned alot. I will get to take the old boat out afterall this year after I get a new cylinder.
Greatly appreciated!