Power Steering Pump: Testing and Inspection

POWER STEERING: VANE PUMP (for 2AR-FE): INSPECTION

1. INSPECT VANE PUMP SHAFT AND BUSHING IN VANE PUMP FRONT HOUSING

(a) Using a micrometer, measure the outer diameter [a] of the vane pump shaft with pulley.





(b) Using a vernier caliper, measure the inner diameter [b] of the vane pump front housing bushing.

(c) Calculate the oil clearance.

Oil clearance = Inner diameter of the bushing [b] - Outer diameter of the shaft [a].

Maximum oil clearance:

0.07 mm (0.0028 in.)

If oil clearance exceeds the maximum, replace the vane pump assembly.

2. INSPECT VANE PUMP ROTOR AND VANE PUMP PLATE CLEARANCE

(a) 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.)

If the thickness is not within the specified range, replace the vane pump assembly.

(b) Using a feeler gauge, measure the clearance between the side face of the vane pump rotor groove and the vane pump plates.





Maximum clearance:

0.03 mm (0.0012 in.)

If clearance exceeds the maximum, replace the vane pump assembly.

3. INSPECT FLOW CONTROL VALVE ASSEMBLY

(a) Coat the flow control valve assembly with power steering fluid and check that it falls smoothly into the flow control valve due to its own weight.





If the control valve does not fall into the hole smoothly, replace the vane pump assembly.

(b) Check the flow control valve assembly 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 hole.





If air leaks, replace the vane pump assembly.

4. INSPECT FLOW CONTROL VALVE COMPRESSION SPRING

(a) Using a vernier caliper, measure the free length of the flow control valve compression spring.





Minimum free length:

29.2 mm (1.150 in.)

If the length is less than the minimum, replace the vane pump assembly.

5. INSPECT PRESSURE PORT UNION

If the union seat in the pressure port union is severely damaged, replace the vane pump assembly.

6. INSPECT TOTAL PRELOAD

(a) Check that the pump rotates smoothly without abnormal noise.





(b) Temporarily install the service bolt.

Recommended service bolt:

Thread diameter
10 mm (0.39 in.)

Thread pitch
1.25 mm (0.0492 in.)

Bolt length
50 mm (1.97 in.)

(c) Using a torque wrench, check the pump rotating torque.

Rotating torque:

0.27 N*m (2.8 kgf*cm, 2.4 in.*lbf) or less

If the rotating torque is not as specified, check the vane pump housing oil seal.