Car Jack Specifications

Updated February 21, 2017

Car jacks are used to lift a portion of a vehicle for simple repairs such as changing a tire. Larger jacks can lift the front or back end of a car for more complex repairs. Professional-quality jacks are sometimes used in auto repair shops to lift vehicles, or in car parks to store cars. These devices are also referred to as car lifts.

Scissor Car Jacks

A scissor car jack is a device constructed with a cross-hatch mechanism, much like a scissor, to lift up a car for repair or storage. It typically works in just a vertical manner. The jack opens and folds closed, applying pressure to the bottom supports along the crossed pattern to move the lift. Scissors car jacks come with many new vehicles since they're portable and can be stored in a car boot. When closed, they have a diamond shape. Scissor jacks may have motorised controls to lift a heavier vehicle, such as a camper or RV. The largest scissors jacks lift and store cars in makeshift car parks. For example, the Carparx Vehicle Parking and Storage system by Titan Worldwide is 94 inches wide and 228 inches long and can lift up to 3175kg. The lift is powered by a hydraulic pack and accompanying controls.

Air-Powered Car Jacks

Vehicle owners without enough muscle to work a scissor jack can use an air-powered jack lift. These devices use compressed air to lift up a vehicle The pallet is placed under the rear wheels --- or other lifting point --- and then the user works an air-control valve to lift the car to the desired height. Air jacks range from a 1.25-ton bumper jack to an axle air jack than cam lift up to 22 tons. The exhaust air jack, a newer version of this type of lift, contains a hose that attaches to the exhaust pipe to fill up a balloon placed underneath the car with air. This can lift up a 3-ton car for up to 45 minutes.

Hydraulic Jacks

Consisting of two cylinders --- one containing fluid and another with a large piston to lift a vehicle --- a hydraulic jack raises cars using a "pulley" type system. The user presses upward on a hand lever to pump fluid from a pipe into the small cylinder. When the user turns the lever down, the fluid moves into the main cylinder. A valve stops the fluid from returning to the small or "pumping" cylinder. By turning a second, or release valve, liquid leaves the main cylinder and returns to the smaller one. One type of hydraulic jack, a bottle jack, which is shaped like a soda bottle, uses a screw top that extends up to nine inches. The valve on the bottom of the jack must be turned clockwise until it is shut for the ram (extension rod) to work. To retract the extension rod, turn the valve counterclockwise, ensuring that there's no weight left on the bottle jack. Otherwise, you may be injured. A bottle jack can lift anywhere from 8 to 50 tons, despite its small size.

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About the Author

Marianne Moro is a copywriter and journalist based in Hollywood. She has been writing professionally since 1999, specializing in home remodeling, interior decorating, pets, travel and holistic health. Moro was a part-time editor and contributing writer for, a home remodeling and decorating website, and has also contributed to the Cutting Chair and Entertainment Today.