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HOMESERVICE MANUALSCHEVROLET2003TRAILBLAZER 4.2 S, 4WDREPAIR AND DIAGNOSISEXTERNAL PAGESDIFFERENT CARSECTION 1277 (POWER STEERING SYSTEM)REPAIR INSTRUCTIONSPOWER STEERING PUMP DISASSEMBLEINSPECTION PROCEDURE
2003 Chevrolet TrailBlazer 4.2 S, 4WD

Inspection Procedure

2003 Chevrolet TrailBlazer 4.2 S, 4WDSECTION Inspection Procedure
WARNING: This page is about a different car, the 2003 Pontiac Vibe. However, it is still accessible from the selected car via links, so may be relevant.
  1. Measure the outside diameter (b) of the pump shaft (2).
    Fig 1: Determining Clearance Of Pump Shaft Seal
    G01545603Courtesy of GENERAL MOTORS CORP.
  2. Measure the inside diameter (a) of the pump shaft hole in the front housing (1).
  3. Calculate the clearance for the pump shaft seal. If the clearance is not within the specifications, replace the power steering pump.
    1. Specification 
    2. The minimum clearance for the pump shaft seal is 0.021 mm (0.0008 in). The maximum clearance for the pump shaft seal is 0.070 mm (0.0028 in).
  4. Measure the height (a) of each vane (1).
    Fig 2: Measuring Vanes
    G01545604Courtesy of GENERAL MOTORS CORP.
    1. Specification 
    2. The minimum height of each vane is 7.60 mm (0.299 in).
  5. Measure the length (c) of each vane.
    1. Specification 
    2. The minimum length of each vane is 11.993 mm (0.4722 in).
  6. Measure the thickness (b) of each vane.
    1. Specification 
    2. The minimum thickness of each vane is 1.405 mm (0.0553 in).
  7. Use a feeler gage in order to measure the clearance between each vane and the corresponding slot in the rotor. If the dimensions of the rotor or the vanes are not within the specifications, replace the pump.
    1. Specification 
    2. The maximum clearance between a vane and the rotor is 0.030 mm (0.0012 in).
  8. Measure the free length of the flow control valve spring (1). If the free length of the spring is not within the specification, replace the pump.
    Fig 3: Measuring Free Length Of Flow Control Valve Spring
    G01545605Courtesy of GENERAL MOTORS CORP.
    1. Specification 
    2. The minimum free length of the spring is 36.9 mm (1.45 in).
  9. Complete the following steps in order to test the flow control valve:
    1. 9.1. Use your finger in order to plug 1 hole on the side of the valve.
    2. 9.2. Apply compressed air, 392-490 kPa (57-71 psi) to the other hole on the side of the valve.
    3. 9.3. If air exits the hole in the bottom end of the valve, replace the valve.
    4. 9.4. Apply fluid to the valve.
    5. 9.5. Apply fluid to the flow control valve hole in the front housing.
    6. 9.6. Hold the pump front housing in a position in order to insert the valve vertically into the housing.
    7. 9.7. Insert the valve into the front housing. If the valve does not slide smoothly into the front housing, replace the pump.
  10. Inspect the pump inlet tube and the front housing. If the pump inlet tube does not seal properly against the front housing, replace the pump.
  11. If the pump components meet the specifications, assemble the pump. Refer to POWER STEERING PUMP ASSEMBLE  . If the pump components do not meet the specifications, replace the pump. Refer to POWER STEERING PUMP REPLACEMENT  .
RENDER: 1.0x

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