Some floor jacks have a safety mechanism called an overload valve that keeps the jack from lifting more weight than it is rated for. The valve will automatically release any excess pressure if the jack is overloaded, preventing damage to the jack and ensuring the safety of the person using it.
How does a Floor jack overload valve work?
A floor jack overload valve typically works by using a spring-loaded mechanism that is set to release at a certain pressure level. The spring is placed under compression as the jack is used to lift a load, and as the pressure within the jack increases, the spring is compressed more. When the pressure reaches the level at which the spring is set to release, the valve will open, allowing oil to flow out of the jack and release the excess pressure. This prevents the jack from lifting more than its maximum rated load capacity and ensures the safety of the person using it.
Where is the Floor jack overload valve located?

How to adjust a floor jack overload valve?
It is not recommended to adjust the overload valve unless it is necessary. However, here is a general overview of the steps involved:
- Locate the overload valve on the jack.
- Use the manufacturer’s instructions to determine the proper pressure setting for the jack.
- Use a wrench or pliers to loosen the locknut that holds the spring in place.
- Now use a screwdriver to adjust the spring tension by turning the adjusting screw.
- Use a pressure gauge to measure the pressure in the jack while it is lifting a load.
- Adjust the spring tension until the pressure in the jack matches the recommended pressure setting.
- Tighten the locknut to hold the spring in place and re-check the pressure setting.
- Test the jack by lifting a load to ensure that it functions properly and that the pressure relief valve is working correctly.
Adjusting the overload valve should only be done by a qualified technician or mechanic, as it requires knowledge of the working mechanism.