Leak Testing

^ Tools Required
- J 24460-01 Cooling System Tester, or equivalent

CAUTION: Do not use boil-out tanks that have been used for copper or brass radiators. The flux and caustic cleaners remaining in these tanks will attack the aluminum radiator causing failure. Use a separate tank containing clean water for servicing aluminum and plastic radiators.

1. Remove the radiator from the vehicle.
2. Clean the radiator core so the damaged area can be seen.





^ Remove dirt and insects from the fins with a common water hose, without the nozzle. Excessive water pressure could damage the fins.
^ Scrub the core with a soft-bristle brush using clean, hot water and a mild detergent.
3. Radiator core leaks can be found by adding water to the radiator.
4. Install test fittings or rubber test caps in the inlet and outlet necks, as shown.





5. Install plugs in the transmission oil cooler fittings to keep dirt out, if equipped.
6. Install plugs in the engine oil cooler fittings, if equipped.





7. Attach the cooling system tester to the radiator.
8. Gradually apply normal system pressure, never exceed 138 kPa (20 psi).
9. The needle on the tester gage will remain steady, if there are no leaks.
^ Help find small leaks by applying soapy water to suspect areas, or submerge the radiator assembly in a large water tank.
^ Check for bubbles at the point of leakage.
10. Damage to a plastic side tank requires replacement.