Subaru 2009 IMPREZA Service Manual page 2668

C: INSPECTION
1. BASIC INSPECTION
Perform the following inspection procedures and replace faulty parts.
No. Parts
1 Oil pump (Exterior)
2 Pulley
3 Oil pump (Interior)
4 O-ring
5 Bracket
Oil Pump
Inspection
(1) Crack, damage or oil leakage
(2) Play of pulley shaft
(1) Damage
(2) Bend
(1) Faulty or seized of vane pump
(2) Bend in the shaft or damage to
bearing
Cracking or deterioration
Crack
PS-45
POWER ASSISTED SYSTEM (POWER STEERING)
Corrective action
Replace the oil pump with a new part.
Measure the radial play and axial play.
If any of these exceeds the service limit, replace the oil
pump with a new part.
Replace with a new part.
Measure the V groove deflection.
If it exceeds the service limit, replace the pulley with a
new part.
Check the rotating resistance of pulley.
If it exceeds the service limit, replace the oil pump with
a new part.
If the a string is wrapped on the pulley and rotated, and
the oil pump emits a noise that is markedly different in
tone and loudness from a sound of a new oil pump,
replace the oil pump with a new part.
Replace with a new part.
Replace with a new part.