DD15 Coolant Leaks Troubleshooting

Check as follows:‪

1. Clean the engine.
2. Fill the coolant system if low.
3. Attach a pressure test kit.
4. Pressurize the coolant system per OEM specs.
5. Check for external leaks, are any leaks found?.
   1. If yes, repair as necessary.
   2. If no, check the EGR cooler for leaks. Refer to “8.6.1 EGR Cooler Leak Test” .

EGR Cooler Leak Test

Test as follows:‪

Note: Before performing this procedure, turn off the engine and allow it to cool. But coolant should be warm (above 140°F/60°C).

1. Remove Marmon clamps from the hot pipe and remove the pipe.
2. Remove EGR mixer pipe.
3. Disconnect Delta P Sensor connector.
4. Disconnect Coolant Inlet Temperature Sensor connector.
5. Remove the Delta P venturi pipe.
6. Unbolt and move the exhaust gas crossover tube, lifting the eye to the side away from the EGR cooler.
7. Install W470589019100 onto the EGR cooler. Install the hot pipe cap (2) with the supplied Marmon clamp (3) on to the hot pipe end. Install the cold pipe plug (1) into the cold pipe end and retain it with the supplied clamshell and clamp (4).
   
8. Use regulator from kit J–41473 and apply 30 psi air pressure to the cooler. Close the valve and disconnect the air supply.
9. Wait for 30 minutes and record the air gauge reading. There should be no drop in pressure. There should be bubbles in the surge tank if the cooler is leaking internally. If there is a pressure drop and there are no bubbles, use a soap and water solution to make sure that there are no leaks externally from the test kit.
10. Is the cooler leaking internally?
    1. If yes, change the cooler. Refer to “5.1 Exhaust Gas Recirculation (EGR) Cooler” in the “Engine” chapter of the EPA07 DD15 Workshop Manual (DDC-SVC-MAN-0002).
    2. If no, troubleshoot for other internal coolant system leaks. Check for coolant out exhaust from an exhaust port and check for internal engine damage.