Weak hydraulic jack

[Porkchopx]

My passenger rear jack seams to have lost its oomph. If I try lifting the back-end with both jacks as soon as the jacks start taking on weight the passenger side jack gives up and the drivers side jack keeps lifting. Also if I try just running the passenger rear jack it will quit lifting after taking on some weight even though it is not fully extended. I can hear the motor still running but the jack is no longer extending.

Any suggestions are appreciated.

thx!

[ajm12]

Well first are your jacks Electric or Hydraulic. If it is Hydraulic it could be the pistons in that cylinder is leaking back. Make sure your fluid level is correct.

[Porkchopx]

Hydraulic and the fluid level is good. The manufacturer is Power Gear and I found a troubleshooting guide that says "Cartridge valve faulty". Now trying to figure out how to test that.