Vane Pump: Inspection

WARNING: This page is about a different car, the 2006 Scion tC. However, it is still accessible from the selected car via links, so may be relevant.

INSPECT VANE PUMP SHAFT AND BUSH IN HOUSING FRONT
1. Using a micrometer and caliper gauge, measure the oil clearance.
  Maximum oil clearance: 0.07 mm (0.0028 in.)
  
  If the oil clearance exceeds the maximum, replace the vane pump assembly.
  
  Fig 1: Inspecting Vane Pump Shaft And Bush In Housing Front
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
INSPECT VANE PUMP ROTOR AND VANE PUMP PLATES
1. Using a micrometer, measure the thickness of the vane pump plates.
  Standard thickness: 1.405 to 1.411 mm (0.05531 to 0.05555 in.)
  
  Fig 2: Measuring Thickness Of Vane Pump Plates
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Using a feeler gauge, measure the clearance between a side face of the vane pump rotor groove and the vane plates.
  Maximum clearance: 0.03 mm (0.0012 in.)
  
  If the clearance exceeds the maximum, replace the vane pump assembly.
  
  Fig 3: Measuring Clearance Between Side Face Of Vane Pump Rotor Groove And Vane Plates
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
INSPECT FLOW CONTROL VALVE
1. Coat the flow control valve with power steering fluid and check that it falls smoothly into the flow control valve hole under its own weight.
  If it lacks smoothness, replace the vane pump assembly.
  
  Fig 4: Inspecting Flow Control Valve
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Check the flow control valve for leakage. Close one of the holes and apply compressed air, 392 to 490 kPa (4 to 5 kgf/cm² , 57 to 71 psi), into the opposite side hole, and confirm that air does not come out from the end holes.
  If air leaks, replace the vane pump assembly.
  
  Fig 5: Checking Flow Control Valve Leakage
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
INSPECT FLOW CONTROL VALVE COMPRESSION SPRING
1. Using a vernier caliper, measure the free length of the compression spring.
  Minimum free length: 36.9 mm(1.453 in.)
  
  If the length is less than the minimum, replace the vane pump assembly.
  
  Fig 6: Measuring Free Length Of Compression Spring
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
INSPECT PRESSURE PORT UNION
If the union seat in the pressure port union is severely damaged, it may cause fluid leakage. In that case, replace the vane pump assembly.