GM Service Manual Online
For 1990-2009 cars only

The air dryer attaches directly to the automatic level control air compressor head and provides the following two functions:

    • The air dryer contains a dry chemical which absorbs moisture from the compressed air before it goes to the air shocks. The moisture is later removed from the chemical when the dry air is exhausted from the air shocks and passes back through the dryer.
    • The air dryer contains a valve arrangement which maintains a minimum pressure of 55-97 kPa (8-14 psi) in the air shocks at all times in order to minimize friction between the air shock sleeve and the body. This minimum pressure feature improves vehicle ride and shock reliability.