WARNING: This page is about a different car, the 2004 Pontiac Sunfire, 2004 Chevrolet Classic, and 2004 Chevrolet Cavalier. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Checking Forward Clutch With Air Pressure
Courtesy of GENERAL MOTORS CORP.
With air pressure set at 20 psi, check the forward clutch to verify proper operation of the seals and clutch assembly.