S570 Hydraulic Pressure Questions - Issues

[sittinlow88]

Hi all, I just received an S570 that is lacking lifting power, the tilt function seems better but not perfect. When the machine/hydraulic system is cool both lift and tilt function better than when everything achieves operating temps, then the lift struggles to work at all. I started by changing out the hydraulic fluid and the 2 hydraulic filters. The filter housing for the charge filter (located on the cooling fan) had captured a lot of silver/metal, the fluid looked like a very fine silver paint. The fluid drained from the reservoir and the fluid inside the filter housing for the return filter (Top near the radiator) looked normal in color with no traces of metal. I then connected a pressure gauge to the inboard most quick-connect fitting on the hydraulic valve block and got these readings: -Cold readings- Full tilt relief pressure: 1800 Full lift relief pressure: 2500 -Operating temp readings- Full tilt relief pressure: 1800 Operating tilt pressure: 1100+ (climbs rapidly while using) Full lift relief pressure: 1100 Lift operating pressure: 600 Do these readings and the metal residue in the charge filter housing indicate a failing gear pump? (I have zero prior service records so I have no clue when or if the charge filter had ever been replaced) Or is it possible that the relief valve(s) are opening too soon or stuck open? Are there other tests or different ports I should check for pressure? Thank you in advance for your help!!!

 

[Tazza]

I'm suspecting the gear pump too, hot or cold, you should be getting 2,500-3,000 psi at the quick couplers.
The only way to know for sure is to get it tested. They will load it down and check the flow to see if it's worn or not.

 

[sittinlow88]

I'm suspecting the gear pump too, hot or cold, you should be getting 2,500-3,000 psi at the quick couplers.
The only way to know for sure is to get it tested. They will load it down and check the flow to see if it's worn or not.

How is it tested? Is it a bench test where I need to remove the pump?

 

[bobbie-g]

How is it tested? Is it a bench test where I need to remove the pump?

I had the pump on my 863 tested by a dealer several years ago (before I bought it). Pretty sure they didn't have to remove it. But I'm also pretty sure they tested it for both flow and pressure. ---Bobbie-G

 

[Tazza]

I had the pump on my 863 tested by a dealer several years ago (before I bought it). Pretty sure they didn't have to remove it. But I'm also pretty sure they tested it for both flow and pressure. ---Bobbie-G

The dealer will test it in the machine i believe, they hook up other hoses to do it.
Hydraulic shops may have a test bench that they can use to test the pump, so that is an option too. I believe loader parts source had a test bench, but depends on how far they are from you to see if postage there and back is worth it or not.