Snap-On YA 700 won't go up

[johninct]

My Snap-On YA-700 jack will only go up 1 inch. I used it today, it wouldn't go up so I jacked it a few times then jacked up a car to full height. 10minutes later it only will go up 1 inch. I can stand on the saddle and it holds my weight then I turn the handle and it drops fine. The jack doesn't leak oil so I am thinking the plunger thing is bad (replaced it 20 years ago).

 

[Hiball]

My Snap-On YA-700 jack will only go up 1 inch. I used it today, it wouldn't go up so I jacked it a few times then jacked up a car to full height. 10minutes later it only will go up 1 inch. I can stand on the saddle and it holds my weight then I turn the handle and it drops fine. The jack doesn't leak oil so I am thinking the plunger thing is bad (replaced it 20 years ago).

Just tear it down and Inspect the Individual Parts, generally if the Pump piston is compromised, It will show signs of leakage. Is the Vent missing? Maybe a Oil Intake issue account gunk in the Reservoir? The Best policy is just to Dive in..