K 20 3/4 Ton Pickup 4WD L6-292 4.8L VIN T 1-bbl (1983)
Cruise Control Servo: Testing and Inspection
1.
Disconnect vacuum hose from servo and apply approximately 14 inches of vacuum to servo using a suitable pump with an integral gauge.
2.
If servo loses more than 5 inches of vacuum in 1 minute, servo is defective. Connecting vacuum hoses can be checked using a similar test
procedure.