Air suspension systems are coming into prominence because of certain advantages they possess over the conventional metal springs. Their advantages are :-

1. A variable space for wheel deflection is put to optimum use by virtue of the automatic control devices.

2. Because the vehicle attitude is also constant, changes in head lamp alignment due to varying loads are avoided.

3. The spring rate varies much less between the laden and unladen conditions, as compared with that of conventional steel springs. This reduces the dynamic loading.

4. The improved standard of ride comfort and noise reduction attained with air springs reduces both driver and passenger fatigue.



  • Two generally used types of air springs are bellow type spring and Piston type spring. 
  • Both can be employed in a wishbone type independent suspension system. 
  • Internal volume of the bellows is reduced during bounce, which means that the air pressure inside the spring is increased as it is compressed, that is the spring becomes stiffer. 
  • Due to this the optimally comfortable ride is provided under all conditions. 
  • A vehicle with electronic air suspension can provide about three times softer ride as provided by conventional coil springs, simultaneously absorbing bumps and protecting against bottoming, due to variables spring rate. 
  • The four air springs, which may be either the bellows type or the piston type are mounted on the same position where generally the coil springs are mounted. 
  • An air compressor takes the atmospheric air through a filter and compresses it to a pressure of about 240 MPa, at this pressure the air in the accumulator tank is maintained, which is also provided with a safety relief valve. 
  • This high pressure air goes to the lift control valve and the levelling valves, to the air springs. 
  • The lift control valve is operated manually by means of a handle on the control panel, through a cable running from the valve to the handle.