Volvo Penta SX-A Trim Pump Troubleshoting

Status
Not open for further replies.

Brewru

Recruit
Joined
Jun 19, 2013
Messages
2
I am having the age old problem when it comes to trim, the darn thing don't seem to work. I suspect that hydraulic fluid is being extracted from the reservoir when trimming up or down and instead of returning to the reservoir as it comes back from the cylinder it is somehow getting into the case that holds the trim pump assembly. This leads to the reservoir running dry and the trim pump eventually sucking air from the reservoir while all of the fluid sits in the case surrounding the pump assembly. Here is where I am in the troubleshooting process.

The trim motor is receiving power and I can hear the pump working when I attempt to trim up or down. If I unscrew the reservoir lid, fill it with fluid, and attempt to trim up it will work albeit the trim moves very slowly. After getting it to trim all the way up I can get it to trim up and down successfully for a while, but again, it works very slowly.

Two days ago after pulling my boat out of the water the motor would not trim up, I opened the reservoir cap, heard a relief of air pressure/vacuum, and the trim resumed it's "normal" very slow operation.

Yesterday after pulling the boat out of the water it would again not trim up. I tried opening the cap, again heard some air escape or enter, but this time it would not resume operating. I pulled the pins and used a cargo strap to keep the outdrive in the up position to trailer it home.

Today I removed the hyd lines from the pump assembly cover and as expected some fluid came out. Then when I removed the trim pump cover a LOT of fluid came out, pretty sure that's not supposed to happen right? Then when I removed the pump assembly and went to drain the fluid from the reservoir it was basically empty, also not suppose to happen right?

I tried posting a link of the schematic of the pump but apparently I am not allowed to post links. I also tried posting a picture of the aft view of the pump assembly, but it will not let me do that either so I'll do my best to explain. After some investigation I discovered that the right port supplies pressure to trim "up" and the left port supplies pressure to trim "down". I assume that as pressure goes to the "up" line the "down" line becomes a return line and returns fluid to the same port that supplies "down" pressure when operating the system in the other direction. Am I correct? Also, there are two other holes inboard of the "up" and "down" pressure ports, they look like they maybe some sort of return ports as well with small ball bearings in each one. I tried to use a very small screw driver to force the ball bearing in but they did not budge. Any experts on hydraulics that could give me some pointers?
 

w88dm4n

Cadet
Joined
Aug 6, 2018
Messages
8
Any resolution to your problem? I have a very similar issue.

Mine began to trim slowly. After noticing a milky leak, I replaced the cover assembly and hoses with the new design. Still slow.
 

GA_Boater

Honorary Moderator Emeritus
Joined
May 24, 2011
Messages
49,038
Any resolution to your problem? I have a very similar issue.

Mine began to trim slowly. After noticing a milky leak, I replaced the cover assembly and hoses with the new design. Still slow.

We ask to not post in dormant threads which are inactive for 90 or more days. Why? Well you are asking for a reply from an OP who last visited shortly after making these two posts over two years ago. Don't hold your breath!

If you want answers, start a new thread so currently active members can assist.

Closed.
 
Status
Not open for further replies.
Top