Coolant Leak Testing

Special Tools

• EN-471  Adapter
• EN-6327-A  Cooling System Test Adapter

For equivalent regional tools, refer to Special Tools .

1. Detach the coolant expansion tank closure 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. Check the coolant level.
   Fig 1: View Of Coolant System Tester, KM-471 And KM-6327

   Courtesy of GENERAL MOTORS COMPANY

   Top up the coolant to the COLD mark if necessary.

3. Pull the coolant expansion tank from the bracket in the direction of the battery.
4. Attach the coolant system tester (1) with EN-471  adapter (2) and EN-6327-A  adapter (3) to the coolant expansion tank.
   NOTE: Follow manufacturer instructions.
5. Apply approximately 100 kPa (15 psi) to the cooling system.
6. Cooling system, check for leaks.
7. Detach the cooling system tester.
   • Release the pressure
   • Detach the cooling system tester with EN-471  adapter.
8. Attach the coolant expansion tank closure cap.
9. Slide the coolant expansion tank onto the bracket.