1996 GMC Safari Owner's Manual - Page 344

Steering Column Lock Check While parked, and with the parking brake set, try to turn the key to LOCK in each shift lever position. 0 Park on a fairly steep hill, with the vehicle facing downhill. Keeping your foot on the regular brake, set the parking brake. 0 The key should turn to LOCK only when the shift lever is in PARK (P). The key should come out only in LOCK. To check the parking brake: With the engine running and transmission in NEUTRAL (N), slowly remove foot pressure from the regular brake pedal. Do this until the vehicle is held by the parking brake only. To check the PARK (P) mechanism's holding ability: With the engine running, shift toPARK (P). Then release all brakes. Parking Brake and Automatic Transmission FARK (P) Mechanism Check 0 I When you are doing this check, your vehicle could begin to move. You or others could be injured and property could be damaged. Make sure there is room in frontyour vehicle in case of it begins to roll. Be ready to apply the regular brake atonce should the vehicle begin to move. 7-44