Coolant Leak Testing

WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2011 GMC Yukon XL, 2011 GMC Yukon, 2011 Chevrolet Tahoe, 2011 Chevrolet Suburban, and 2011 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.

Special Tools

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

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.

Remove the pressure cap.
Test the operation of the pressure cap. Refer to Pressure Cap Testing .
Wash the pressure cap mating surface with water.

Fig 1: Applying Pressure To Cooling System

Courtesy of GENERAL MOTORS CORP.

Use the J 24460-01 with the J 42401 in order to apply pressure to the cooling system.
Do not exceed the pressure cap rating.
The cooling system should hold the rated pressure for at least 2 minutes.
Observe the gauge for any pressure loss.
Repair any leaks as required.