What are the reasons for coolant leakage from the water pump of an Audi A6?

[LaJoshua]

Audi A6 water pump coolant leakage can be caused by several reasons as follows: 1. Excessive axial movement of the water pump rotor: The interference between the auxiliary seal and the shaft is too large, preventing the dynamic ring from moving flexibly on the shaft. Leakage occurs due to the inability to compensate for displacement after wear of the dynamic and static rings during pump operation. 2. Insufficient lubrication on the sealing surface: This leads to dry friction or scoring of the sealing surfaces, resulting in water pump leakage. 3. Periodic vibration of the rotor: This is caused by misalignment between the stator and the upper/lower end covers, imbalance between the impeller and the main shaft, cavitation, or bearing damage (wear). This situation will shorten the seal life and cause leakage.