Floor jack question - Daytona 3 Ton

[EAnglum]

Quick question...I've used google and can't find this condition anywhere when searching.

I have a Daytona 3 Ton floor jack (yellow) I purchased from Harbor Freight a few years ago. The jack has worked great however I recently noticed a strange condition.

If the valve is open to lower the jack and I pump it up, it will lift slightly towards the very end of the swing - last few inches before the pole is fully extended down. It will stay slightly elevated until I let the pole return up, then it will lower again. If I close the valve, it lifts no problem (holds the vehicle) and lowers with no issue...assuming the pole is allowed to raise slightly. Hope that makes sense...

I've topped off the fluid with jack oil and bled the system numerous times.

Any ideas on what could be causing this?? We just finished our addition/garage build so it spent most of the winter stored in my shed (unheated)...can't see how that could have caused any issues?

 

[EAnglum]

Here is a picture showing how high it lifts when the pole is fully extended down, with the valve wide open. It will not go any higher unless I close the valve.

 

[Wamsutta]

I just now went out and checked mine. I have the same jack. Mine will raise the arm a little bit with the valve fully open, but comes back down after the handle is all the way down parallel with the floor.