Tilt/ trim problem - need new hydraulic pump?

[probee773]

Hello, I've searched the forum and come up dry. Here is my problem: I have a 1993 Wellcraft Excel 18sx with a Volvo Penta 230A (AQ131) and 290 SP CD trim outdrive. When I bought the boat a year ago, you could tilt the outdrive all the way up, and over the course of a couple of weeks, it would slowly sag until it was trimmed all the way down. This wasn't a problem because it took so long to sag. But, I have since taken the boat out multiple times, ran aground once or twice and beat up the outdrive hydraulics a bit. Now, the outdrive won't move at all. The electric pump motor runs, but the outdrive stays put. Do I need to replace the hydraulic pump housing? Would you recommend i have it rebuilt? The part number on it is 854437 which has been replaced by 3856596. Where is the best place to either get a new one, or have it rebuilt? I am in the Orlando, FL area. Thanks in advance!

 

[probee773]

Re: Tilt/ trim problem - need new hydraulic pump?

This is the only post without a reply Guess we don't have too many hydrauloholics out there!

 

[wire2]

Re: Tilt/ trim problem - need new hydraulic pump?

I saw your post but have had little experience with Volvo.

From a diagnostic standpoint, I'd suggest remove the trim cylinder ends from the outdrive, then operate the trim.

Do both cylinders extend/retract freely?
Does the outdrive lift by hand easily?

I expect one of those will be a "no".

 

[probee773]

Re: Tilt/ trim problem - need new hydraulic pump?

Thanks wire2. Are you suggesting the problem may possibly be in the trim cylinders themselves? I sure hope not. I tried to remove these cylinders a while back, but they are pretty much locked in to the transom shield and won't budge.

 

[whywhyzed]

Re: Tilt/ trim problem - need new hydraulic pump?

sounds like one of the cylinders is bypassing internally across the piston seals- run the pump for about 3 minutes - put your hand on each cylinder - is 1 warmer? if it is, you found where the oil is bypassing. A second person can sometimes hear the oil bypassing in 1 cylinder.

 

[probee773]

Re: Tilt/ trim problem - need new hydraulic pump?

Another thing to note here, I have had a very small fluid leak on rams for quite some time.

I'm going to take the hydraulic pump to be rebuilt. I will keep you posted as this progresses. Wish me luck! :redface:

 

[whywhyzed]

Re: Tilt/ trim problem - need new hydraulic pump?

that was weird

 

[Bondo]

Re: Tilt/ trim problem - need new hydraulic pump?

Hmmmmmmm,.........

Is there any Oil in the Pump,..??..??.....

 

[probee773]

Re: Tilt/ trim problem - need new hydraulic pump?

Yes, the pump is full of oil. The trim leak is very very small.

 

[wallydc2]

Re: Tilt/ trim problem - need new hydraulic pump?

If the rams are leaking, why are you rebuilding the pump? Disconnect rams from lower unit as suggested earlier and see if they work. You may have bent one running aground or your cylinders need to be rebuilt.

 

[probee773]

Re: Tilt/ trim problem - need new hydraulic pump?

Anyone know where I can find hydraulic pressure testing equipment for this application? A friend of mine suggested that I test the pressure coming out of the pump to see if the pump is even working, and to see if the check valve in the pump is holding the pressure out.

Any thoughts?

 

[CarolinaWhaler]

Re: Tilt/ trim problem - need new hydraulic pump?

Check the yellow pages for industrial cylinder info. I've worked in the hydraulic business for most of my life. All cylinders are the same concept, just different materials. An industrial hydraulic and pneumatic shop should have a test stand. Have them hook it up and give their thoughts.

 

[CarolinaWhaler]

Re: Tilt/ trim problem - need new hydraulic pump?

One more thing, as stated above by another, if you're leaking fluid then a piston seal and gland kit my be in your future. If the pump is running but peaking, it is probably do to that jammed cylinder. My thoughts are the pumps fine, your cylinder rod may be bent... If that's what the industrial shop tells you just scrap it and buy a new unit.