Aftercooler - Continued
Aftercooler must be removed from truck; see REMOVAL preceding.
A trace or crystal deposit left by evaporated coolant often indicates a potential leak or weak spot. If any
trace of coolant or deposits are noticed, carry out step 11 following, prior to aftercooler cleaning.
Aftercooler repair is limited to the replacement of seal rings in the grooves of the water inlet and water
outlet tube ends. The only other repair is cleaning of the aftercooler which is governed largely by the kind
of coolant and coolant additive used in the engine cooling system.
Check all of the cooler fins and air and water passages for plugging. Clean all obstructions from the fins using
a small soft bristle brush.
Death or serious injury could occur if compressed air is directed against the skin. Do not use compressed
air for cleaning or drying unless the pressure is/has been reduced to 30 psi (2.11 kg/cm2) or less. When
working with compressed air always use chip guards, eye protection and other personal protective
Blow all excess dirt from aftercooler fins using compressed air.
Steam clean the outside of the core to remove any loose deposits.
Dry cleaning solvent P-D-680 (safety or Stoddards solvent) is potentially dangerous. Avoid repeated and
prolonged breathing of vapors and skin contact with the liquid. Do not use near open flame, arcing
equipment or other ignition sources. Always wear eye protection and protective clothing. The flash point of
P-D-680 is 100 to 138 deg. F (30 to 59 deg. C).
Use dry cleaning solvent (item 10, Appendix B), clean oil and dirt from the aftercooler. If core has an
excessive build up of dirt or carbon, allow aftercooler to soak in metal cleaner for about 12 hours. Leave the
water connections open so that the cleaning solution can penetrate both the coolant and air sides of the
Remove the core from the cleaning solution and rinse It thoroughly with a steam cleaner or high pressure hot
Blow out the air and water sides of the core using compressed air. To ensure that loose debris is not forced
further into the fins, direct the stream of air opposite to the direction of normal coolant and air flow.
Rinse the core with clean dry cleaning solvent (item 10, Appendix B) to remove any residual oil or grease.
Rinse the solvent from the core using a steam cleaner or high pressure hot water rinse.