GM Service Manual Online
For 1990-2009 cars only

Cleaning Procedure

  1. Clean the water crossover in solvent.
  2. Caution: Wear safety glasses in order to avoid eye damage.

  3. Dry the water crossover with compressed air.

Inspection Procedure


    Object Number: 578757  Size: SH
  1. Inspect the water crossover for the following:
  2. • Corrosion or damage to the threads for the following connections:
       - Engine lift bracket bolt holes (1)
       - EGR inlet pipe mounting bolt hole (3)
    • Corrosion or damage to the radiator hose outlet (2)
    • Corrosion or damage to the water pump drive belt tensioner/shield mounting bolt holes (5)
    • Corrosion, damage or restrictions to the seal/gasket sealing surfaces for the following:
       - EGR inlet pipe port (4)
       - Water pump sealing area (6)
       - Water crossover gasket sealing surfaces (7)
    • Corrosion, damage or restrictions to the EGR passages (8)
    • Corrosion, leakage or damage to the engine coolant plug (9)

    Object Number: 578724  Size: SH
  3. Inspect the water crossover for the following:
  4. • Corrosion, leakage or damage to the engine coolant plug (1)
    • Corrosion or damage to the heater hose fitting (6)
    • Corrosion or damage to the water crossover bolt holes (7)
    • Corrosion or damage to the water pump mounting tabs (9)
    • Corrosion, restrictions or damage to the seal/gasket sealing surfaces for the following:
       - EGR valve ports (3)
       - EGR pipe port (5)
    • Corrosion or damage to the threads for the following connections:
       - EGR valve mounting bolt holes (2)
       - EGR pipe mounting bolt holes (4)
       - Heater hose fitting hole (6)
       - Water pump cover bolt holes (8)
       - Throttle body engine coolant outlet fitting hole (10)
  5. Inspect for damage or sevicability the following components:
  6. • Water pump and seal
    • Thermostat and seal
    • Water outlet
    • Water pump cover and seal
    • EGR valve
    • Rear engine lift bracket
    • Throttle body engine coolant outlet fitting
    • Heater hose fitting
    • Bolts and fasteners
  7. Repair or replace the water crossover and/or components as necessary.