Some core leaks can be detected by adding water to the radiator. Clean the core so that the damaged area can be found.

1. Remove dirt and insects from the fins with a common water hose without a pressure nozzle. Excessive water pressure can damage the fins.
2. Scrub the core with a soft-bristle brush using clean, hot water, or hot water with a mild detergent.

Tools Required

J 24460-01 Cooling System Tester

1. With the system at a cool temperature, remove the radiator cap.
2. Connect the tester and apply normal system operating pressure.

Do not exceed 138 kPa (20 psi) of pressure.

3. Watch the gauge needle for an indication of a leak. Examine the radiator and other cooling system components for escaping coolant.
4. Repair the hose and hose connections as required.
5. Check the radiator cap in order to ensure that it will maintain the correct pressure.
6. If the radiator leaks during the pressure test, mark the leak area.

1. Install the test fittings or the rubber test caps over the inlet and outlet necks.
2. Attach the pressure tester and apply 138 kPa (20 psi) of air pressure.
3. Check the pressure gauge in order to see if there is a loss of pressure.

In order to ensure that there are no small leaks, run water over the repair area and look for bubbles (a mild detergent is also helpful). If a large water tank is available, submerge the radiator and check for air bubbles.