Power Steering Vane Pump: Inspection

Fig 1: Measuring Pump Rotor Vane Plates

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1. Using a micrometer, measure the height, thickness and length of the 10 vane plates.
   1. Minimum height: 5.4 mm (0.213 in.) 
   2. Minimum thickness: 0.882 mm (0.0347 in.) 
   3. Minimum length: 4.596 mm (0.1809 in.) 
2. Using a feeler gauge, measure the clearance between the vane pump rotor groove and vane plate.
   Fig 2: Measuring Clearance Between Vane Pump Rotor Groove & Vane Plate

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   Maximum clearance: 0.023 mm (0.0009 in.) 

   If it is more than the maximum, replace the vane plate and/or vane pump rotor with the one having the same mark stamped on the cam ring.

   Inscribed mark: 0, 1, 2, 3, or 4 

   Fig 3: Locating Inscribed Marks On Vane Pump Rotor & Cam Ring

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   NOTE: There are 5 vane plate heights corresponding to the following vane pump rotor and cam ring marks:
   Fig 4: Determining Vane Plate Part No. & Length Based On Inscribed Mark

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1. Coat the flow control valve with power steering fluid and check that it falls smoothly into the valve hole of the rear housing by its own weight.
   Fig 5: Inspecting Flow Control Valve

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2. Check the flow control valve for leakage. Close one of the holes and apply compressed air of 392 - 490 kPa (4 - 5 kgf/cm² , 57 - 71 psi) into the opposite side hole, and confirm that air does not come out from the end hole.
   Fig 6: Using Compressed Air To Check Flow Control Valve

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   If necessary, replace the flow control valve with the one having the same letter as inscribed on the rear housing.

   Fig 7: Locating Inscribed Mark On Flow Control Valve & Housing

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   Inscribed mark: A, B, C, D, E or F 

Using vernier calipers, measure the free length of the spring.

Fig 8: Measuring Free Length Of Spring

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Minimum free length: 28.7 mm (1.130 in.) 

If it is not within the specification, replace the spring.