Stronger than the hand-powered jackscrews but more complex to maintain, floor jacks may experience leaks which is usually due to normal wear and tear. The liquid that comes out of the unit is the fluid that helps in the operation of the hydraulic arm.
Most floor jacks have a common design, and this is one reason why they are easy to fix. Another reason is that there are four spots in a floor jack where one could usually find the source of the leak: Ram/piston rod; compression ram; pressure-release valve; and the fill cap / reservoir. In case you still couldn’t find the source of the leak, it is a thing to look at the pressure-release valve.
The next thing that should be looked at is the lifting arm/handle. If it slowly lowers after you raise it, you have a problem; it’s not supposed to do that. Before starting an inspection, check first the reservoir if it has the right amount of hydraulic fluid in it.
There could be excess air inside the jack system which may be causing the leak. Try pumping such excess air by lifting the arm and allowing it to drop down gradually. But if you have enough hydraulic fluid and had already tried to purge the air out, yet the leak is still there, you’ll need to resort to repairing and/or rebuilding the jack unit.
You can release the pressure by turning the valve; however, the steps in doing so may differ from unit to unit, so consult your owner’s manual on this. To be clear, if your jack needs repairs, this won’t solve the problem. First, release the pressure. Next, drain the old hydraulic fluid out. Depending on your floor jack unit, this may have different steps in doing so. Either way, get familiar with the specific instructions on your owner’s manual and have the necessary tools at hand, which may include adjustable wrenches and a ratchet. You will then need to remove the O-ring and replace it, because it is also a good place to look for leaks.
In disassembling your jack unit, be careful of the springs, if there are any, underneath the pressure cylinder. These are crucial to the operation of the jack, and you’ll have to set them carefully once you’re done. Make sure that the replacement O-ring is compatible with your unit.
Putting back together
Be careful in putting the ram back into the cylinder and pay attention to the O-ring that you’ve just installed; you don’t want any damage on it. Reassemble the housing and put the frames back into position.
In many cases, this has solved the leak problem. If it didn’t, try making sure that the O-ring that you’ve put inside your floor jack is completely compatible, or else it might leak again.
Aside from replacing old broken parts of your floor jack, it is advisable to have your unit cleaned every now and then. Dirt and other contaminants can deal damage to the insides of your jack, and eventually cause the wheel repairs again. Take time in taking care of your floor jack; a well-maintained floor jack will go the distance.