By MercedesMedic on May 24, 2019
This guide provides instructions on how to change the water pump on Mercedes-Benz cars. In this guide, you will find how to video, pictures and other tips to help you replace your Mercedes water pump.
The instructions in this guide apply to M112, M113, M272 and M273 engines, found on many models including C, E, S, CLK, ML, GL, SLK, CLS, G, R class, etc.
Do not continue to operate your car if the water pump fails. If you continue to drive your Mercedes-Benz, you risk causing severe damage to your engine including blowing the head gasket, cracking cylinder head or seizing the engine. All these are costly repairs and in some cases may require the engine to be replaced entirely. If your Mercedes water pump fails, it is better to get the car towed, than risk causing additional engine damage.
This is a list of the key parts and tools needed.
Removing the radiator cooling fan is recommended so that you can have more room to work. The fan is very easy to remove. Disconnect the wire harness remove the clips or bolts that secure the fan to the radiator and pull the cooling fan shroud up.
You must verify Mercedes water pump torque specifications by calling your dealer. Torque values vary between engines. The values below are for M112 and M113 engines.
|Alternator bolt||40 Nm|
|M6 Bolts (not pre-tapped)||15 Nm|
|M6 Bolts (pre-taped)||10Nm|
|M8 (Not pre-tapped)||35 Nm|
|Idler Pulley||10 Nm|
The easiest way to check for a bad Mercedes water pump bearing is to use a mechanic's stethoscope and check for noise near the water pulley.
A common symptom that your Mercedes water pump is bad, is the engine overheating or coolant leak at the front of the engine. A water pump symptoms develop over time before the pump completely fails.
One way to check if your water pump is failing is to remove the serpentine belt and check the water pump for play and inspect for coolant leaks
The primary purpose of the water pump on your Mercedes-Benz it to circulate the coolant in your engine's cooling system. The most common symptoms of a failed Mercedes-Benz water pump is the engine overheating or a small coolant leak.
Mercedes-Benz water pumps suffer from two main issues.
When the seal fails it will cause the coolant to leak. If the bearing fails, it will cause abnormal engine noise. Below is a list of possible symptoms caused by a bad Mercedes water pump.