Volvo SX Trim Pump Noise

[rwidman]

Just recently, when I trim the Volvo SX drive up or down (on the trailer) instead of the usual whine, there is a "knocking" sound simmilar to the sound of the fresh water pressure pump operating. The trim pump fluid level seemed to be at about the low mark on the reservoir so I added fluid but that didn't help. When I removed the cap on the reservoir, it was pressurized. I have a Seloc manual for the drive but there is no mention of this problem in the trouble shooting chart. So far, the trim still works.<br /><br />Any suggestions?

 

[Don S]

Re: Volvo SX Trim Pump Noise

Is the noise coming from the pump, or the trim cylinders/drive area?

 

[rwidman]

Re: Volvo SX Trim Pump Noise

It seems to be coming from the pump. The boat hull amplifies the sound. When it was first noticed it would make the noise during part of the raising or lowering. Now it seems to be constant while the pump is operating.

 

[Don S]

Re: Volvo SX Trim Pump Noise

If the oil in the reservoir was low, there must be a leak somewhere, probably on the cylinders if you don't see any leaks inside. Was the oil that was left in the reservoir milky looking?<br />Since it was low, you may just have air in the system. Fill the reservoir and run it up and down a few times to bleed the air out of the system and see if the knocking goes away.

 

[rwidman]

Re: Volvo SX Trim Pump Noise

There was a leak where the hose attached to the cylinder but I had that repaired last fall. I didn't check the fluid level after that and the boat has been used and the drive raised and lowered several times since then. The fluid did not look "milky". I tried raising and lowering the drive like the manual suggests. I'll do it several more times to see if it bleeds the air out.<br /><br />The manual says that there is a vent hole in the filler cap. I don't see one and each time I remove it there is a hissing sound of pressure or vacuum being released. This is a 2002 or 2003 model.

 

[Lou C]

Re: Volvo SX Trim Pump Noise

Don't know for sure on the Volvo SX but on my OMC Cobra the manual tells you to tilt the drive all the way up before checking the fluid level or it can come out under pressure, I wonder if the Volvo is the same since it used parts of the Cobra design. Could there be some loosness in the mounting of the trim cylinders that are contributing to the noise you hear?

 

[rwidman]

Re: Volvo SX Trim Pump Noise

I put a screwdriver with the handle to my ear and the blade on the drive (sort of a redneck stethescope) and didn't hear it. I can hear it well on the hull in the area where the pump is mounted. I'll try removing the cap and working the drive up and down.

 

[mikeneal]

Re: Volvo SX Trim Pump Noise

I had to replace a trim cylinder hose on the VP SX drive and it took a quite a few up-down cycles to purdge the air.

 

[rwidman]

Re: Volvo SX Trim Pump Noise

Thanks for all the suggestions. I removed the cap and ran the drive up and down several times but the noise remains. I have a "friend of a friend" who owns a boat service shop and when I described the noise to her, her response was "Did you check the fluid?"<br /><br />I suppose I'll use it for a while and see what happens.