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Floor Jack Overload Valve Adjustment Process

An overload valve of a floor jack primarily exists so that the jack does not exceed the weight limit of the hydraulic press, which might cause it to break down. Overload valves stop the press from lifting further up if the weight limit is crossed.

The floor jack overload valve adjustment process is very straightforward and only requires you to follow a set of simple steps. However, if you’re trying to adjust the overload valve, chances are that your floor jack is having some trouble holding pressure. In that case, we have some solutions for that as well.

Stick around till the end to various additional information regarding the issue you might be facing.

To learn how to adjust an overload valve, it is helpful to know how it works in the first place.

An overload valve is a safety measure to protect the hydraulic press from unwanted damage due to excessive pressure. It works by loosening the connection between the jack handle and the hydraulic press.

When a certain weight limit is reached, the overload valve disconnects the handle and the press, preventing it from pushing further.

How To Adjust Safety Valve on Floor Jack

When we’re talking about adjusting the overload valve, we’re mainly changing the max weight capacity of the floor jack. To do that, you just need the right screwdriver. It varies from model to model, some use Philips heads while others use binding heads.

Once you’ve got the right screwdriver, find the location of the safety valve. There will be a shield on top of it that you’ll have to remove with the screwdriver. Spot the screws and turn them counterclockwise to release the shield.

After you’ve done that, the valve should be exposed to you. There are mainly two types of valves used on floor jacks. The handle valve and the screw valve. Handle valves have a handle, while screw valves have a hole for the screw to go through. 

Depending on which one your model has, you’ll have to approach it differently.

how to adjust a floor jack valve

Type 1: Handle Valve Adjustment

For a handle valve, you just have to hold on to the handle and rotate it to adjust the weight overload on the floor jack. Rotate it clockwise to increase the maximum weight capacity and counterclockwise to decrease it.

These valves are typically very sensitive so a small turn could drastically change the output. So, try it in small amounts and figure out the correct amount for you.

Type 2: Screw Valve Adjustment

For a screw valve, you will need a corresponding screwdriver. Typically it is the same as the shield’s screws, but according to your model, it could be different.

Once you’ve gotten your hands on the right screwdriver, simply insert it into the hole. Spin in clockwise to increase the overload and counterclockwise to decrease it. The screw will probably be very stiff, but don’t put too much force. Gently rotate the screwdriver and make small changes.

Test out the floor jack to see whether you need to increase it further or not.

Safety Note: Before attempting to put pressure after adjustments, check the instruction manual of the floor jack for the maximum supported weight capacity. Normally, the valve will be set to 90% of that max capacity. So, you can at best increase it to 100%. Going beyond that will be very risky as it can damage both the floor jack and your vehicle.

What To Do If A Floor Jack Doesn’t Hold Pressure?

This is a very common issue for which people consider adjusting the overload valve. A loose valve can indeed cause your floor jack to suffer such problems. However, that’s not the only cause.

Here are some suggestions you can try out if your floor jack can’t hold pressure even after adjusting the overload valve:

Inspect Hydraulic Oil Levels

The hydraulic press will fail to operate if the oil levels are above or below the given margins. Also, if the oil is of low quality, it might cause friction which can also prevent it from working properly. To maintain the proper hydraulic level,  you should fill your jack with oil correctly and safely.

To know exactly what types of fluid are used in a floor jack, check out this article where we have explained and recommended the hydraulic fluid to use in your jack.

Remove Trapped Air

Hydraulics work by using highly pressurized compressed air. After long-term use, some of that air can leak into other parts of the machine causing havoc. The air mostly gets trapped in the oil chamber. To remove air from the floor jack, you just need to bleed it.

Check For Damage

The final most obvious consideration would be that the floor jack is damaged. In most cases, it’s the hydraulic press. Repairing a broken floor jack is not worth the effort and the money. You’re better off getting a new floor jack.


Keep in mind that the overload valve is a safety measurement. So, a floor jack overload valve adjustment should only be done under your own circumstances. To be on the safe side, never exceed the given weight limit of your floor jack.

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