Impreza WRX STI F4-2.5L DOHC Turbo (2007)
Water Pump: Testing and Inspection
Water Pump
Inspection
1. Check the water pump bearing for smooth rotation.
2. Check the water pump pulley for abnormalities.
3. Check the impeller for damage or abnormal deformation.
4. Check the clearance between impeller and pump case.
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Clearance between impeller and pump case:
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Standard ............................................................................................................................................................... 0.5 - 1.5 mm (0.020 - 0.060 in)
5. After water pump installation, check the pulley shaft for engine coolant leaks. If leaks are noted, replace the water pump assembly.