Cooling System Maintenance: Refilling
WARNING: This page does not describe the selected car, but rather 37 other vehicles, including the 1986 Pontiac Sunbird, 1986 Pontiac Parisienne, 1986 Pontiac Grand Prix, 1986 Pontiac Grand Am, and 1986 Pontiac Firebird. However, it is still accessible from the selected car via links, so may be relevant.
Engine should be running while refilling cooling system to prevent air from being trapped in the engine block. After system is full, continue running engine until thermostat is open, then recheck fill level. Do not overfill system.