Cooling System Pressure Testing
WARNING: This page is about a different car, the 1988 Pontiac 6000, 1988 Oldsmobile Cutlass Cruiser, 1988 Oldsmobile Cutlass Ciera, 1988 Chevrolet Celebrity, and 1988 Buick Century. However, it is still accessible from the selected car via links, so may be relevant.
- With engine off, wipe radiator filler neck seat clean. Fill radiator to correct level. Attach tester to radiator and pump until pressure is at upper limit of radiator rating.
- If pressure drops, inspect for external leaks. If no leaks are apparent, detach tester and run engine until normal operating temperature is obtained. Reattach tester and observe. If pressure builds up immediately, a possible leak exists from a faulty head gasket or crack in head or block.CAUTION: Pressure may build up quickly. Release any excess pressure or cooling system damage may result.
- If there is no immediate pressure build up, pump tester to within system pressure range (on radiator cap). Vibration of gauge pointer indicates compression or combustion leak into cooling system. Isolate leak by shorting each spark plug wire to cylinder block. Gauge pointer should stop or decrease vibration when leaking cylinder is shorted.CAUTION: Do not disconnect spark plug wires while engine is operating, or operate engine with spark plug shorted for more than one minute, as catalytic converter may be damaged.
- Remove engine and transmission (automatic only) oil dipsticks and check if water drops appear in oil. If so, a serious internal leak is indicated. If all checks are negative and system holds pressure for 2 minutes, there are no serious leaks in system.