Hybrid Cooling System Leak Test

Special Tools

• EN-24460-A  Cooling System Pressure Tester
• GE-46143  Radiator Cap and Surge Tank Test Adapter

For equivalent regional tools, Refer to Special Tools

1. Remove the pressure cap.
   WARNING: Under pressure, the temperature of the solution in the radiator can be considerably higher, without boiling. Removing the radiator cap while the engine is hot (pressure is high), will cause the solution to boil instantaneously, with explosive force. The solution will spew out over the engine, fenders and the person removing the cap. Serious bodily injury may result. Flammable antifreeze, such as alcohol, is not recommended for use at any time. Flammable antifreeze could cause a serious fire.
   WARNING: In order to help avoid being burned, do not remove the radiator cap while the engine and the radiator are hot. Scalding fluid and steam can be blown out under pressure if the cap is removed too soon.
2. Test the operation of the pressure cap. Refer to Hybrid Cooling System Pressure Cap Testing .
3. Wash the pressure cap mating surface with water.
4. Use the EN-24460-A  Cooling System Pressure Tester with the GE-46143  Radiator Cap and Surge Tank Test Adapter in order to apply pressure to the cooling system.

   Do not exceed the pressure cap rating.

   Fig 1: Cooling System Pressure Tester Components

   Courtesy of GENERAL MOTORS COMPANY
5. The cooling system should hold the rated pressure for at least 2 minutes.

   Observe the gauge for any pressure loss.

6. Repair any leaks as required.
   NOTE: Do not use stop leak or any other chemicals. Only use premix Dexcool (50/50 mixture of Dexcool and deionized)