Power Steering Pump: Testing and Inspection

POWER STEERING: VANE PUMP: INSPECTION

INSPECTION





1. INSPECT OIL CLEARANCE
(a) Using a micrometer and caliper gauge, measure the oil clearance.
Standard clearance:
0.03 to 0.045 mm (0.0012 to 0.0018 in.)
Maximum clearance:
0.07 mm (0.028 in.)
If the clearance is greater than the maximum, replace the vane pump housing front and vane pump shaft.
2. INSPECT VANE PUMP ROTOR AND VANE PUMP PLATES





(a) Using a micrometer, measure the height, thickness and length of the 10 vane pump plates.
Minimum length:





If the thickness is less than the minimum, replace the vane pump.





(b) Using a feeler gauge, measure the clearance between the rotor groove and plate.
Maximum oil clearance:
0.028 mm (0.0011 in.)
If the oil clearance is greater than the maximum, replace the vane pump.
3. INSPECT FLOW CONTROL VALVE





(a) Coat the valve with power steering fluid and check that it falls smoothly into the valve hole by its own weight.
If not as specified, replace the vane pump.





(b) Check the flow control valve for leakage.
A C Close either hole A or B and apply 392 to 490 kPa (4 to 5 kgf*cm2, 57 to 71 psi) of compressed air into the opposite side. Confirm that air does not come out from the end hole C.
If air leaks from hole C, replace the vane pump.





4. INSPECT FLOW CONTROL VALVE COMPRESSION SPRING
(a) Using a vernier caliper, measure the uncompressed length of the spring.
Minimum uncompressed length:
36.9 mm (1.45 in.)
If the length is less than the minimum, replace the spring.