An auto lift is a necessary tool in any automotive repair shop, whether the shop is a one-bay family business or a 30-bay shop in an auto dealership. Unfortunately, an auto lift can be a very dangerous tool because it is used to support a massive load above a work area.

There are several common types of auto lifts used in repair shops, namely inground one and two post lifts, above ground two post lifts, and above ground four post lifts. Inground lifts can be further divided into low pressure lifts and high pressure lifts. These describe the fluid pressure levels used to extend the lift.

The advantages of an inground lift are that it takes up little space and it does not interfere with the mechanic’s ability to open the doors of the vehicle being lifted. In a small repair shop, the mechanic has more room to move around the vehicle when the lift is employed, and he has more work space in the shop when the inground lift is retracted to its stored position in the floor. In a large shop using inground lifts means that the dealer has room for more lifts and is able to increase his throughput of repairs, thus enhancing the profitability of his service business.

A low pressure floor to floor lift is powered by the compressed air system in the shop. The advantages of a low pressure lift over a high pressure lift are that the low pressure lift has fewer moving parts and does not require a dedicated hydraulic system. These advantages typically result in an installed savings. The low pressure lift is able to provide comparable lifting force to the load.

The shop air is plumbed to an external reservoir which is filled with hydraulic fluid. The reservoir is plumbed hydraulicly to the auto lift cylinder. When the shop air pressurizes the hydraulic fluid, the fluid becomes pressurized and applies force directly to the piston in the lift to raise the load on the lift.

And also when the scissor car elevator lift in a position representing almost full retraction to the floor level, the arms contact the vehicle to be lifted and the plate which connects the rotating arms to the plunger in order to keep this illustration simple. The lift contains hydraulic fluid, but the pressurized air is actually used to contact the working face of the plunger and to raise the load. The hydraulic fluid is used as a means of sealing the pneumatic pressure and of controlling the speed of the plunger through use of an orifice in the bottom of the plunger.