NOTE: This procedure applies to Rear Gear Train engines only. For Front Gear Train engines, refer to the vehicle
manufacturer’s service information.
In order to pressure test the EGR cooler for leaks, a test fitting must be fabricated to connect compressed air to the
EGR cooler coolant inlet.
Obtain a straight thread plug, Part Number 3089567, and remove the o-ring seal assembled on the straight thread
plug.
Drill and tap the straight thread plug internally to 118 NPT.
Insert a brass number 4 fitting, Part Number 68138, into the tapped hole.
Remove the EGA coolant inlet fitting and install the new test fitting, fabricated in the previous step, along with the
sealing washers.
Plug the EGA cooler vent fitting by installing a straight thread plug, Part Number 3678923.
NOTE: Some early built engines require a 1/8 inch NPT pipe plug instead of a straight thread plug.
Install a section of 3,4 inch automotive heater hose between the EGR cooler coolant inlet line and the EGR cooler coolant outlet line.
Secure the hose to the lines with spiral hose clamps.
Connect a regulated air supply hose, Part Number 3164231, or equivalent, to the newly-fabricated test fitting.
• Make sure the air pressure regulator is closed, then connect compressed air to the pressure regulator.
• Apply 483 kPa [70 psi] of air pressure to the cooler.
• Inspect for air escaping the EGR cooler assembly as a result of loose lines and fittings by spraying a mixture of mild soap and water at the fitting and line connections. Air leaks at these locations will not give accurate test results, and it will lead to EGR coolers being replaced when they are not defective.
• Shut off the air supply to the regulator by using the ball valve and disconnect the compressed air slowly.
• Record the time that the air supply was shut off and the air pressure shown on the air pressure gauge.
• Periodically check the fittings for air leaks using the mixture of soap and water. If there are any leaks found during this test, fix the leak and start the test over.
• Measure and record the air pressure after 20 minutes.
• If there is no pressure drop, the cooler is reusable.
• If the measured pressure drop is greater than 138 kPa [20 psi], replace the EGR cooler.
• If the measured pressure drop is 138 kPa [20 psi] or less, check all of the fittings for air leaks to make sure that no air leaks are found on the test equipment and test again.
• If the pressure drops on the second test and there are no air leaks found on the test equipment, replace the EGR cooler.
NOTE: Open the ball valve to release any pressure in the EGR cooler before removing the test fittings.
Once the parts are cleaned and tested, cover open points with protective caps from the Air Handling Clean Care Kit,
Part Number 4919498.
If the EGR cooler is not usable:
• Verify there are no issues with the cooling system (coolant leaks, water pump damage, fan drive damage,
or similar). Refer to Procedure 008-020 in Section 8.
• Coolant deposits can typically be identified as dried white deposits coating the inside of the housings.
• Inspect the turbocharger turbine housing for signs of coolant deposits. Refer to Procedure 010-033 in Section 10.
• Inspect the EGR valve inlet for signs of coolant deposits. Refer to Procedure 011-022 in Section 11.
• Replace the crankcase breather element. Refer to Procedure 003-021 in Section 3.
• Verity that there is no coolant contamination in the engine lubricating oil.
