How to Fix a Leaky Floor Jack

What You'll Need
New "O" ring kit
Jack fluid
Drain pan
Stable work surface
Flat handle screwdriver
Jack handle
Clamps or heavy objects

Anyone who does any work around vehicles will need to use a floor jack. This tool is invaluable in lifting sections of the vehicle in order to work underneath it. Floor jacks come in different sizes for being able to lift different sized vehicles. Through normal wear and tear, a floor jack can begin to leak the fluid with operates the hydraulic lifting arm. Fixing a leaky floor jack is fairly easy and a part of general maintenance. 

Step 1 - Place Jack on Work Surface

In order to fix the leak in your floor jack you will need to place it on a solid work surface. Since floor jacks can be heavy, make sure that the work table is heavy duty and clear of any debris or obstacles. 

Step 2 - Loosen Valve Screw

In order to get at the "O" ring in the floor jack you will need to loosen the valve screw. This is the screw that rises and lowers the jack with the handle. Use the jack handle and turn the screw in a counter clockwise direction. 

Step 3 - Stand Floor Jack on End

After you have loosened the valve screw a little, stand the floor jack up on its end so that the screw is pointing at the ceiling. Stabilize the floor jack with clamps or heavy objects that will not be moved by the weight of the jack. Continue to remove unscrew the screw until you can remove it. 

Step 4 - Drain Fluid From Floor Jack

Chances are that if the floor jack fluid has been leaking it will also have a great deal of debris in the fluid that remains. Set a drain pan on the work table and begin to lower the jack until the fluid drains out of the valve screw hole. Once the fluid has been drained, stand the jack back up on its end.

Step 5 - Replace O Ring on Valve Screw

The biggest reason that the floor jack is leaking is because of a faulty "O" ring. This ring is on the valve screw and can be easily removed by prying it off with a flat handled screwdriver. Clean off the valve screw with a rag and install a new "O" ring. 

Step 6 - Fill Jack with Fluid

The floor jack will not work properly without any jack fluid in the case. Make sure that you have the type of floor jack fluid that the manufacturer recommends. Hold a funnel on top of the valve screw hole and slowly pour in the fluid. Fill the jack until the fluid reaches the level of the threads. 

Step 7 - Replace Valve Screw

With the floor jack full of fluid, replace the valve screw and tighten it with a clockwise direction. Once it is tightened enough not to leak fluid, lower the jack back onto its wheels. Use the jack handle to raise and lower the lifting arm several times to work the fluid through the jack. Make sure that it will hold weight at the top of the lift and that there are not any other leaks.