Pressure Cap Testing

WARNING: This page is about a different car, the 2007 Chevrolet Monte Carlo and 2007 Chevrolet Impala. However, it is still accessible from the selected car via links, so may be relevant.

Tools Required

J 24460-01 Cooling System Pressure Tester. See Special Tools .
J 42401 Radiator Cap/Surge Tank Test Adapter. See Special Tools .

Remove the pressure cap.
CAUTION: To avoid being burned, do not remove the radiator cap or surge tank cap while the engine is hot. The cooling system will release scalding fluid and steam under pressure if radiator cap or surge tank cap is removed while the engine and radiator are still hot.
Wash the pressure cap sealing surface with water.
Use the J 24460-01 (1) with J 42401 (2) in order to test the pressure cap. See Special Tools .

Fig 1: Identifying Special Tools J 24460-01 & J 42401
Courtesy of GENERAL MOTORS CORP.
Test the pressure cap for the following conditions:
- Pressure release when the J 24460-01 exceeds the pressure rating of the pressure cap. See Special Tools .
- Maintain the rated pressure for at least 10 seconds.
  Note the rate of pressure loss.
Replace the pressure cap under the following conditions:
- The pressure cap does not release pressure which exceeds the rated pressure of the cap.
- The pressure cap does not hold the rated pressure.