View Full Version : Hydraulic floor jack repair help

01-23-2009, 04:23 PM
I have an older craftsman floor jack that stopped working and has just been taking up space it is too nice to throw away.

So where should I start looking for problems.

Thanks in advance

01-23-2009, 04:45 PM
As always, approach it in a systematic manner. First check for fluid level, then the valve for pitting/wear/obstructions, then piston plunger (third since it's probably harder to get out than the valve), etc.
This assumes no obvious cracks in the cylinder wall, no sign of having been in a fire.....

Magnetic Mechanic
01-23-2009, 06:01 PM
If it's got fluid the liddle check valve ball may have dirt in it

01-23-2009, 07:08 PM
I had trouble with one and it turned out to be a plugged vent.

These things aren't complicated, at the very worst, you'll have to change some O-rings.

01-23-2009, 09:50 PM
Sometimes a very sharp smack to the pump piston will cure what ails a hydraulic jack.
The pressure spike seems to be able to clear valves and ports, swell seals, purge air traps...

Magnetic Mechanic
01-23-2009, 10:54 PM
That's called percussive maintenance:p

01-23-2009, 10:57 PM
all the above and if that fails its time for a new floor jack

01-23-2009, 11:19 PM
Sometimes a very sharp smack to the pump piston will cure what ails a hydraulic jack.

Or a starter, VCR, Anything mounted in a dashboard, the list goes on and on........

01-24-2009, 10:01 AM
All of my jack instructions indicated that the cylinder should be vented periodically by positioning the oil fill hole up and removing the plug from the fill hole to vent the air. Air in the jack is compressible and the jack will not lift a load if it's air-bound.