Folks,

Fortunately, I don’t depend on one support when I jack up a car.  Today, when I finished the work, my hydraulic jack was all the way down.  But my jack stand kept everything where it should be.  Afterwards, I jacked the car up again to see if it would drop and sure enough it did - not immediately, but with in a few minutes.

So, what now?  Is there maintenance to correct this or is it time for a new jack?

Thanks!

The fluid level is correct ?     Good quality jacks can be serviced, cheap jacks are tossed into the scrap bin.

Seals are probably worn.  If they can be replaced, you'll probably be back in business.

New O-rings, refill oil

Asuming the piston-shaft isn't corroded or damaged.

Assuming OP can find a hydraulic shop to do the job properly for cheaper than out right replacement.

It was $200 less to reseal an ancient porta power than replacing with the same US made one.  I went with replacement.