How to Use Hydraulic Jacks

An average car owner is familiar with a regular jack which uses a screw mechanism. Many of them do not have much experience with hydraulic floor jacks, which use high-pressure liquid displacement and are more efficient than the traditional variety.

Hydraulic floor jacks are commonly associated with professional motor mechanics and with motor racing, but they are readily available for domestic use, and with care they can be used safely by almost anyone.

Jacks are usually used to raise vehicles from the ground so that they can be worked on from underneath, or to allow the tyres to be changed.

The most important step when using a jack is to identify the jacking point on the car. This is commonly about twelve inches behind the front wheel or a similar distance in front of the rear wheel.

If there is any doubt about the location of the jacking point the owner’s manual must be consulted. The jacking point has been designed to bear the weight of the vehicle and it is dangerous to use a jack at an incorrect point on the vehicles body. Attention must also be paid to the condition of the bodywork above the jacking point, as excessive rust or other damage will mean it is weakened and may not support the weight of the vehicle.

The jack should be positioned under the jacking point. It must stand on hard surface that will not move once the jack is in use. Hard ground or asphalt might not be strong enough to support the jack once it is in use, so it is wise to spread the weight by placing one or two large pieces of thick wood or board under the jack.

When working on a wheel, it should be loosened before the vehicle is jacked up. The car should also be placed into first gear or reverse, or if it has an automatic gearbox it should be placed in park.

Hydraulic jacks have a locking mechanism on the handle which ensures they remain in a fixed position. This lock needs to be disengaged so that the handle can be pumped, which raises the jack.

Once the vehicle has been raised to the correct height the locking mechanism must be re-engaged to keep it at the correct height. However, it is unwise to rely solely on the jack to maintain the vehicles position, and jack stands should be put in place under the correct suspension components. Once the stands are in place the vehicle should be lowered slightly so that it is seat on the stands.

When work on the car is complete, the process is reversed. The vehicle is raised slightly to allow removal of the jack stands, and is then lowered completely and the jack removed.

Hydraulic floor jacks are more expensive than the traditional screw jacks and they are also much larger. However, they are quick and easy to for the average car owner to use and provide an excellent solution in a domestic environment.