Power Steering Vane Pump: Inspection

Using a micrometer and caliper gauge, measure the oil clearance.

Standard clearance: 

0.03 - 0.05 mm (0.0012 - 0.0020 in.) 

Maximum clearance: 0.07 mm (0.0028 in.) 

If it is more than the maximum, replace the vane pump shaft and front housing.

Fig 1: Identifying Oil Clearance Between Vane Pump Shaft And Bushing

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1. Using a micrometer, measure the height, thickness and length of the 10 vane plates.

   Minimum height: 8.6 mm (0.339 in.) 

   Minimum thickness: 1.40 mm (0.0551 in.) 

   Minimum length: 14.99 mm (0.5902 in.) 

   Fig 2: Inspecting Vane Plate

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2. Using a feeler gauge, measure the clearance between the vane pump rotor groove and vane plate.

   Maximum clearance: 0.033 mm (0.0013 in.) 

   Fig 3: Measuring Clearance Between Vane Pump Rotor Groove And Vane Plate

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

Inscribed mark: 1, 2, 3, 4 or None 

Fig 4: Identifying Inscribed Marks

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HINT:

There are 5 vane plate lengths with the following rotor and cam ring marks:

Fig 5: Rotor And Cam Ring Marking, Vane Plate Part No. And Vane Plate Length Table

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1. Coat the flow control valve with power steering fluid and check that it falls smoothly into the valve hole by its own weight.
   Fig 6: 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 392 - 490 kPa (4-5 kgf/cm² , 57 - 71 psi) into the opposite side, and confirm that air does not come out from the end holes.

Fig 7: Checking Control Valve For Leakage

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

Inscribed mark: A, B, C, D, E or F 

Fig 8: Identifying Inscribed Marks

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

Minimum free length: 33.2 mm (1.307 in.) 

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

Fig 9: Measuring Free Length Of Spring

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