Subaru LEGACY 2003 Service Manual page 22

COOLING
C: INSPECTION
1) Check water pump bearing for smooth rotation.
2) Check water pump pulley for abnormalities.
3) Using a dial gauge, measure impeller runout in
thrust direction while rotating the pulley.
"Thrust" runout limit:
0.5 mm (0.020 in)
4) Check clearance between impeller and pump
case.
Clearance between impeller and pump case:
Standard
0.5 — 0.7 mm (0.020 — 0.028 in)
Limit
1.0 mm (0.039 in)
5) After water pump installation, check pulley shaft
for engine coolant leaks. If leaks are noted, replace
water pump assembly.
WATER PUMP
CO-00028
CO-00029
CO(H4SO)-20