Intercooler: Service and Repair
CHARGE AIR COOLER REPAIRS1. Determine what type of damage has been done to the charge air cooler (CAC).
Charge Air Cooler Cross-Reference Chart (Part 1):
Charge Air Cooler Cross-Reference Chart (Part 2):
2. Refer to the Charge Air Cooler Cross-Reference Chart to determine if the damage is repairable and what types of repairs can be made.
Welding Repairs - Sidemembers
1. All surfaces to be welded must be free of all paint, oil, grease, water and other foreign material in the area, so the weld repair will adhere to the bare aluminum and will not be contaminated.
2. Cut a V-shaped groove along the length of the crack to a depth equal to the member thickness.
3. Weld-fill the groove.
- Use a suitable MIG welder.
4. Wire brush and grind any excess weld material to provide a flat surface.
5. Clean the CAC.
Welding Repairs - Mounting Brackets
1. All surfaces to be welded must be free of all paint, oil, grease, water and other foreign matter in the area, so the weld repair will adhere to the bare aluminum and will not be contaminated.
2. CAUTION: Care must be taken not to melt the fins or the tube-to-header braze joint. If welding near the core, shield the core with a large steel plate. This will protect it from sparks and weld splatter and will act as a heat sink.
Tack-weld the bracket in place.
- This will retain the bracket in its correct orientation.
- Use a suitable MIG welder.
3. Weld the bracket in place.
- Use a suitable MIG welder.
4. Allow the bracket to air-cool.
5. Check the bracket alignment.
6. Clean the CAC.
Welding Repairs - Tubes or Tube Header Joints
1. All surfaces to be welded must be free of all paint, oil, grease, water and other foreign material in the area, so the weld repair will adhere to the bare aluminum and will not be contaminated.
2. Weld the tube or tube header joint.
- Use a suitable MIG welder.
- Use Alcan MIG Electrode Wire, 1.20 mm (3/16 in) diameter, 4043 aluminum alloy, aluminum wire or equivalent.
3. Clean the CAC.
Epoxy Repairs - Tubes or Headers
1. All surfaces to be repaired must be free of all paint, oil, grease, water and other foreign material in the area, so the epoxy will adhere to the bare aluminum and will not be contaminated.
2. Apply epoxy to the damaged tube or header.
- Use only a high-temperature epoxy.
- Use resin CIBA GEIGY ARADLITE AV 138M and hardener CIBA GEIGY HV 998 or equivalents.
- The mix and cure instructions on the products must be strictly adhered to.
3. Clean the CAC.
Cleaning After Weld or Epoxy Repairs - Power Flushing
1. Orient the CAC so that the tank containing the repair or closest to the repair point is at the bottom.
2. Power flush the CAC from the opposite tank at the top.
- Power flush with water at a rate of 1.5 mm (0.06 in) per second for 3 minutes.
3. Invert the CAC.
4. Power flush the CAC in the opposite direction.
- Power flush with water at a rate of 1.5 mm (0.06 in) per second for 3 minutes.
5. Drain all of the water from the CAC and allow it to air-dry.
6. NOTE: A leak test must be carried out on all repairs prior to painting or installing the CAC.
Leak test the CAC.
Cleaning After Weld or Epoxy Repairs - Alternate Method
1. Lay the CAC flat with the inlet and outlet ports pointing up.
2. Fill the CAC to 40 percent of its volume with water.
3. Agitate the CAC by hand for at least 10 minutes.
4. Drain the water from the CAC.
5. Repeat Steps 1 through 4 until no foreign material is found in the flushing water.
6. Allow the CAC to air-dry.
7. NOTE: A leak test must be carried out on all repairs prior to painting or installing the CAC.
Leak test the CAC.
Leak Test - Charge Air Cooler
1. NOTE: All repaired CAC must be leak tested and pressure checked prior to painting or installing into the vehicle.
Install an air pressure gauge in one port of the CAC.
2. Install a stop/air supply in the other port.
3. Apply 50 psig of air pressure.
4. Reduce air pressure to 29 psig.
5. Let the CAC stand for a few minutes and note any loss in pressure.
- If the pressure loss exceeds 1.5 psig per minute, repair the leak.
6. Install a new CAC if there is any permanent distortion.