Rams not holding under pressure

jbauman102

Cadet
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Sep 19, 2011
Messages
28
I have a Volvo Penta DP-SM and the trim doesn't hold when cruising it slowly goes down. I rebuilt both rams and it holds a little better but still slowly goes down. I was thinking about buying new ones but cant find them, there the older model 2004 where both hydraulic lines are at the bottom of the cylinder. Does anyone know what the model number is or where I can get them or have any other suggestions. Thank in advanced.
 

alldodge

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Mar 8, 2009
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40,582
I rebuilt both rams and it holds a little better

The rams not holding position can either be leaking ram seals or the trim pump valves. Suggest taking the trim pump apart and looking at it before going for new rams
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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Jul 23, 2011
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47,304
Raise drive, then disconnect lines and cap the lines and plug the cylinder. Then go boating. If the cylinders move, bad piston seals.

If the cylinders do not move..... Bad cross pilot check in the pump
 

alldodge

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Didn't answer right away hoping one with more knowledge would say, but maybe my stiring the pop will cause someone else to come in and confirm or deny

Think the VP uses the Olydine pump which is same as Merc. Just search for Olydine pump kit, should be easy to find
 

QBhoy

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Mar 10, 2016
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8,286
I’d be suspecting it’s the ball valves in the pump now.
 
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