Power Steering Vane Pump: Inspection

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

1. Standard clearance: 0.03-0.05 mm (0.0012-0.0020 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.

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

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1. Using a micrometer, measure the height, thickness and length of the vane plates.
   1. Minimum height: 8.6 mm (0.339 in.) 
   2. Minimum thickness: 1.397 mm (0.0550 in.) 
   3. Minimum length: 14.991 mm (0.5902 in.) 
   Fig 2: Inspecting Vane Pump Rotor And Vane Plates

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2. Using a feeler gauge, measure the clearance between the vane pump rotor groove and vane plate.
   1. Maximum clearance: 0.035 mm (0.0014 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 the one having the same mark stamped on the cam ring.

   1. Inscribed mark: 1, 2, 3, 4 or None 
   Fig 4: Locating Inscribed Mark
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   HINT:

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

   Fig 5: Van Pump Length And Part Table

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1. Coat the flow control valve with power steering fluid and check that it falls smoothly into the flow control 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 392-490 kPa (4-5 kgf/cm² , 57-71 psi) of compressed air into the opposite side hole, and confirm that air does not come out from the end holes.
   Fig 7: Checking Flow Control Valve For Leakage

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   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 Inscribed Mark

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

1. Minimum free length: 32.3 mm (1.272 in.) 

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

Fig 9: Measuring Free Length Of Spring

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