Acura 19200-P8A-A02 Water Pump (Yamada)

Disconnect the cable from the negative battery terminal. Drain the cooling system and if the coolant is relatively new or in good condition, save it and reuse it. Remove the drive belts, followed by the timing belt, timing belt tensioner, and adjuster assembly. Take out the mounting bolts and detach the water pump from the engine. Clean the bolt threads and the threaded holes in the engine to eliminate corrosion and sealant. Compare the new pump with the old one to ensure they are identical. Remove all traces of sealant or O-ring from the engine mating surface. Clean the engine and new water pump mating surfaces with lacquer thinner or acetone. Apply a thin layer of RTV sealant to the O-ring groove of the new pump, and carefully set a new O-ring in the groove. Attach the pump to the engine and thread the bolts into the holes finger tight. Apply a small amount of RTV sealant on the bolt threads, ensuring any dowel pins are in their original locations. Tighten the bolts, reinstall all parts removed for pump access, and reconnect the battery. Finally, refill and bleed the cooling system, check the drive belt tension, run the engine, and ensure there are no leaks.

A failure in the water pump can lead to severe engine damage due to overheating. If the pump seal fails, coolant might leak from the bottom of the timing belt cover through a weep hole on the water pump. After removing the timing belt cover and belt if necessary, inspect for leaks at the top and bottom of the water pump using a flashlight and mirror, paying attention to the area below the crankshaft sprocket. Water pump shaft bearing failure could produce a howling sound near the pump while it's operational; differentiate this from drivebelt slippage, which causes a squealing noise, using a mechanic's stethoscope. Conduct a quick water pump performance check by ensuring the coolant level is full, fully warming up the vehicle, and turning on the heater in the passenger compartment to check for insufficient heat output, indicating possible water pump failure if coolant flow isn't reaching the heater core. Even without leaks or noise, a water pump might still require replacement. The definitive way to determine replacement necessity is by closely examining the pump after removal for issues like a loose or corroded impeller, leaking shaft seal, or worn shaft bearing.

To replace the water pump, start by disconnecting the negative battery cable. Drain the cooling system and save the coolant if it's in good condition. Remove the drivebelt and then the timing belt along with the timing belt tensioner. Take out the water pump mounting bolts and detach the pump from the engine, checking the impeller on the backside for corrosion or missing fins. Ensure that the bolt threads and threaded holes in the engine are free of corrosion. Compare the new pump to the old one to ensure they're identical. Clean the engine mounting surface and remove any traces of the old O-ring. Place a new O-ring into the groove of the new pump and carefully attach the pump to the engine, threading the mounting bolts finger tight while ensuring the dowel pins are in their original positions. Tighten the bolts without overtightening to avoid distortion and leakage. Reinstall all parts that were removed for access to the pump. Refill the cooling system, adjust the drivebelt tension, and reconnect the battery. Run the engine and check for any leaks.

If the pump is defective, replace it with a new or rebuilt unit.