1996 Buick Roadmaster Owner's Manual - Page 327

Steering Column LockCheck While parked, and with the parking brake set, t y to turn r the key to LOCKin each shift 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 yourfoot on the regular brake, set the parking brake. To check the parlungbrake: 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. The key should come out onlyin LOCK. ~ Parking Brake and Automatic Transmission PARK (P) Mechanism Check To check the PARK (P) mechanism's holding ability: Shift to PARK (P). Then release all brakes. Underbody Flushing Service 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 thereis room infront of your vehicle in case it begins to roll. Be ready toapply the regular brake at once shouldthe vehicle beginto move. At least every spring, use plain water flush any to corrosive materials from the underbody. Takecare to clean thoroughly anyareas where mud and other debris can collect.