Genuine Mercedes-Benz C350 Water Pump

Mercedes-Benz C350 Water Pump Parts and Q&A

• Water Pump Assembly
  272-200-09-01-80
  Q: How to check and replace a water pump on Mercedes-Benz C350?

  A:

  When the water pump fails it is possible to cause severe engine damage because the pump overheats and there are two ways to test the water pump outside the engine. In case of fault with the pump then the pump needs to be replaced with new or refurbished pump. The water pumps have weep holes, which leak coolant when the pump seal breaks and there is a howling noisy sound that might be signalling failure of the bearings. Weakness in a shaft, properly check by relieving the tension on the serpentine belt and rocking the water pump pulley, but the drivebelt may slip to produce a squealing, but this is not movement of the bearing. A pump that does not have telltale signs of disfunction such as noise or dripping still may require replacement; corrosion on the impeller fins may interfere with cooling performance. To replace replace the negative battery terminal, air cleaner housing, and, where available, the cooling fan and engine shock absorber. Drain engine coolant, loosen bolts of water pump pulley without removing, and then loosen drivebelt. Just disconnect the pulley and coolant hoses, unbolt the water pump to the engine and inspect it to make sure that there is no corrosion or missing fins of impeller. With the newer V6 engines, coolant must be drained, remove the drivebelt and the trim covers should be peeled off the timing belt idler pulleys before loosening the pulleys. Un-connect the wiring harness and the coolant hose and loosen the pump bolts and remove. Clean the bolt holes and engine pistons, check new pump suits the old, and strip away all old sealant in gaskets. Check the mating surfaces, and, where required, wash the O-ring grooves of the new O-rings. Install the new pump, screw the bolt piece finger tight, use RTV sealant, bolts should be tightened in batches without tightening them too much. Install all components that have been removed, leave the sealant to dry at least an hour, refill and bleed the cooling system, then run the engine to verify that nothing is leaking and it is functioning properly.