6. COOLING SYSTEM MXU 550EXi/MXU500i WATER PUMP MECHANICAL SEAL INSPECTION Inspect the coolant leakage. If there is leakage, the mechanical seal is defective, and water pump body should be replaced. REMOVAL Drain the coolant (refer to the "COOLANT REPLACEMENT" section in this chapter). Loosen the hose bands and disconnect the lower radiator hoses and bypass hose from the water pump. Bypass Hose Remove the four bolts and water pump cover and O-ring. Water Pump Cover/O-ring 6-11