Power Steering Vane Pump: Inspection

Measure oil clearance between vane pump shaft and bushing .

Fig 1: Identifying Vane Pump Shaft & Bushing
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Using a micrometer and a caliper gauge, measure the oil clearance.
1. Standard clearance: 0.021 - 0.043 mm (0.0008 - 0.0017 in.)
2. Maximum clearance: 0.07 mm (0.0028 in.)
If it is more than the maximum, replace the front housing and vane pump shaft.
Inspect vane pump rotor and vane plates .
1. Using a micrometer, measure the height, thickness and length of the 10 vane plates.
  1. Minimum height: 7.6 mm (0.299 in.)
  2. Minimum thickness: 1.405 mm (0.0553 in.)
  3. Minimum length: 11.993 mm (0.4722 in.)
2. Using a feeler gauge, measure the clearance between the vane pump rotor groove and vane plate.
  1. Maximum clearance: 0.025 mm (0.0010 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.
1. Inscribed mark: 0, 1, 2, 3, or 4
  
  Fig 4: Identifying Inscribed Marks
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
NOTE: There are 5 vane plate lengths corresponding to the following vane pump rotor and cam ring marks:

Fig 5: Displaying Plate Length Corresponding Specification
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Inspect flow control valve .
1. Coat the flow control valve with power steering fluid and check that it falls smoothly into the valve hole of the front housing by its own weight.
  
  Fig 6: Installing Flow Control Valve Into Pump Housing
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
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 7: Checking Flow Control Valve For Leakage
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
If necessary, replace the flow control valve with the one having the same letter as inscribed on the front housing.
1. Inscribed mark: A, B, C, D, E or F
  
  Fig 8: Identifying Front Control Valve Letter
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Inspect spring .
Using vernier calipers, measure the free length of the spring.
1. Minimum free length: 36.9 mm (1.453 in.)
If it is not within the specification, replace the spring.

Fig 9: Measuring Spring Free Length
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002