3618 Engine Caterpillar

Before cleaning the aftercooler core, determine if the aftercooler requires cleaning. Use the 152-2067 Differential Pressure Gauge to measure the differential pressure of the air side of the aftercooler. If the differential pressure of the air side is greater than 10 kPa (40 inches of H₂O), clean the aftercooler core.

Cleaning the Aftercooler

See the Service Manual, "Disassembly and Assembly" module for instructions on removal, disassembly, assembly, and installation.

1. Remove the core.

2. Turn the core upside-down in order to remove debris.

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NOTICE
Do not use a high pressure spray for cleaning the fins of the core. A high pressure spray can damage the surface of the fins and reduce the flow of air through the core.

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NOTICE
Do not use a high concentration of caustic cleaner to clean the core. A high concentration of caustic cleaner can attack the internal metals of the core and cause leakage. Only use the recommended concentration of cleaner.

3. Back flush the core with cleaner. Table 1 lists liquid cleaners that are available from your Caterpillar dealer.

   Use a two to five percent concentration of the cleaner at temperatures up to 93 °C (200 °F). Refer to Application Guide, NEHS0526 or consult your Caterpillar dealer for more information.

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   Table 1

   Liquid Cleaners (1)
   Part Number	Description	Size
   1U-5490	Hydrosolv 4165	19 L (5 US gallon)
   174-6854	Caterpillar Cabinet and Tank Liquid Cleaner	19 L (5 US gallon)
   174-6855	Caterpillar Cabinet and Tank Liquid Cleaner	208 L (55 US gallon)

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   ( 1 )

   Use a two to five percent concentration of the cleaner at temperatures up to 93°C (200°F). Refer to Application Guide, NEHS0526 or consult your Caterpillar dealer for more information.

4. Steam clean the core in order to remove any residue. Flush the fins of the aftercooler core. Remove any other trapped debris.

5. Wash the core with hot, soapy water. Rinse the core thoroughly with clean water.

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Personal injury can result from air pressure. Personal injury can result without following proper procedure. When using pressure air, wear a protective face shield and protective clothing. Maximum air pressure at the nozzle must be less than 205 kPa (30 psi) for cleaning purposes.

6. Dry the core with compressed air. Direct the air in the reverse direction of the normal flow.

7. Inspect the core in order to ensure cleanliness. Pressure test the core to a pressure of 1.5 times the working pressure of the cooling circuit for one hour. Many shops that service radiators are equipped to perform pressure tests. If necessary, repair the core.

8. Install the core.

For more information on cleaning the core, consult your Caterpillar dealer.