Centinel System – Repair Manual – 010-027   Charge-Air Cooler

If the engine experiences a turbocharger failure or any other occasion where oil or debris is put into the charge-air cooler, the charge-air cooler must be cleaned.

Remove the charge-air cooler piping and charge-air cooler from the vehicle. Refer to the manufacturer’s instructions.

Use protective caps from the Air Handling Clean Care Kit to cover open points on the plumbing and engine.

CAUTION  Do not use caustic cleaners to clean the charge-air cooler. Damage to the charge-air cooler will result.

Flush the charge-air cooler internally with solvent in the opposite direction of normal airflow. Shake the charge-air cooler and lightly tap on the end tanks with a rubber mallet to dislodge trapped debris. Continue flushing until all debris or oil is removed.

NOTE: Make sure the tubes are in the vertical direction when flushing.

If the debris can not be totally removed from the charge-air cooler, the charge-air cooler must be replaced.

CAUTION  The charge-air cooler must be rinsed, dried, and free of solvent, oil, and debris or engine damage will result.

After the charge-air cooler has been thoroughly cleaned of all oil and debris with solvent, wash the charge-air cooler internally with hot soapy water to remove the remaining solvent. Rinse thoroughly with clean water.

Blow compressed air through the inside of the charge-air cooler in the opposite direction of normal air flow until the charge-air cooler is dry internally.

Use protective caps from the Air Handling Clean Care Kit to cover open points on the charge air cooler after cleaning.

Inspect the charge-air cooler for cracks, holes, or damage.

Inspect the tubes, fins, and welds for tears, breaks, or other damage. If any damage causes the charge-air cooler to fail the air leak check, the charge-air cooler must be replaced.

Install the charge-air cooler on the vehicle.

To check the charge-air cooler for cracked tubes or header, remove the inlet and outlet hoses from the cooler. The charge-air cooler does not have to be removed from the chassis.

WARNING  To prevent possible injury if either plug blows off during the test, secure safety chains on the test plugs to any convenient capscrew on the radiator assembly. This test must not be performed without securely fastened safety chains.

Install the charge-air cooler tester, Part Number 3824556.

Apply 207 kPa [30 psi] of air pressure to the cooler. Close the air pressure regulator.

Determine if pressure decay is caused by a leak in the charge-air cooler or from a leaky connection. Use a spray bottle filled with soapy water and apply to all hose connections. Watch for bubbles to appear at the location of the leak.

If the pressure decay is caused by a leaky connection, repair the connection and repeat the test. If the leak is within the charge-air cooler, repeat the test to verify the accuracy of the pressure decay measurement. Similar pressure decay readings must be obtained in at least three consecutive tests before the reading can be considered accurate.

Monitor the pressure gauge and determine the rate of pressure decay with a stopwatch.

Charge-Air Cooler Pressure Drop

If the pressure drop is greater than the specification listed, the charge-air cooler must be replaced.

Refer to the manufacturer’s repair manual for replacement instructions.

NOTE: If a charge-air cooler leaks more than 49 kPa [5 psi] in 15 seconds, it will appear as a major leak in a leak tank.

NOTE: Charge-air coolers are not designed to be 100-percent leak-free. If the pressure decay is less than 49 kPa [5 psi] in 15 seconds, the charge-air cooler does not need to be replaced.

After the test is complete, cover open points on the charge-air cooler with protective caps from the Air Handling Clean Care Kit.

Inspect the charge-air cooler fins for obstructions to airflow. Remove obstructions such as a winterfront or debris. Manually lock the shutters, if equipped, in the OPEN position.

Install a fluke digital thermometer, Part Number 3822666, and thermocouple wire kit, Part Number 3822988, into the intake air connection.

Install another thermocouple at the air cleaner inlet to the outside of the vehicle.

Perform a road test with the engine at peak power and a vehicle speed of 30 mph or greater.

Record the intake air temperature and the ambient air temperature.

Calculate the differential temperature:

If the temperature differential is greater than the specifications, check the charge-air cooler for dirt and debris on the fins and clean as necessary. If the problem still exists, check the charge-air cooler for debris in the fins or between the charge-air cooler and the radiator. Confirm full fan engagement.

Charge Air Cooler Temperature Rise

Ambient above 0°C [32°F]

Preferred Method: Measure the charge-air cooler system pressure drop with a manometer, Part Number ST 1111-3.

Install one end of the manometer to the tap in the turbocharger compressor outlet elbow.

Install the other end of the manometer to the tap in the intake air connection.

Operate the engine at the maximum advertised horsepower and correlating rpm. Record the readings on the manometer.

Charge-Air Cooler System Differential Pressure

Charge-Air Cooler System Differential Pressure

If the differential pressure is greater than the specification, check the charge-air cooler and associated piping for plugging. Clean or replace if necessary.

If damage resulted in oil, excessive fuel, or excessive black smoke entering the exhaust system, the aftertreatment system must be inspected. Refer to Procedure 014-013 in Section 14.