1998 Oldsmobile Bravada Owner's Manual - Page 346

Ignition Transmission Lock Check While parked, and with the parking brake set, try to turn the ignition key to LOCK in eachshift lever position. The key should turn to LOCK only when the shift lever is in PARK (P). 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 come out only in LOCK. Parking Brake and Automatic Transmission PARK (P) Mechanism Check To check the parking brake's holding ability: With the engine running and transmission in NEUTRAL (N), slowly remove footpressure 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 to PARK (P). Then release all brakes. Underbody Flushing Service When you are doing this check, your vehicle could beginto move. You or otherscould be injured and property could be damaged. Make sure there is room in frontof your vehicle in case it begins to roll. Be ready to apply the regular brake at once should the vehicle begin to move. At least every spring, use plain water to flush any corrosive materials from theunderbody. Take care to clean thoroughly any areas where mud and other debris can collect.