Audi VW Water Pump

Installers Responsibility:

Blauparts recommends that installers take the necessary time to thoroughly follow the steps outlined in this service bulletin to prevent future premature water pump trouble after installation. It has been noted that due to time constraints, inconvenience, and profit, many do not take the extra time needed to thoroughly flush the entire cooling system and properly prepare the gasket mating surfaces. Often when problems arise, such as a coolant leak, the new water pump is blamed as the cause when in fact the opposite is true. It is usually because the installer has neglected to follow these steps listed below.

Flushing the Cooling System:

Just draining and refilling the coolant system is not enough! Premature water pump failure (internal bearings and seals) can occur when cutting corners and failing to flush the entire cooling system and its related components. It is imperative that the cooling system be thoroughly flushed of all accumulated silt and sediment build-up, including all aftermarket cooling system additives, or stop leak products that may have been added to the cooling system (past or present). This would entail completely flushing the engine block, radiator, heater core, and hoses etc. Use distilled water to flush the entire cooling system. Do not use cooling system flush products! Many contain muriatic and/or other acids. Remnants of such acids left in the cooling system can eat away at the internal bearings and seals, causing a new water pump to prematurely fail.

Preparation of Gasket Mating Area & Water Pump Installation:

Some installers have used sealing compounds which significantly reduce the sealing function of the water pump gasket. The key to a factory quality seal is in the preparation of the surface area. Take the extra time to properly clean the water pump gasket and thermostat O-ring surfaces thoroughly. These surfaces should be free of all old gasket material and corrosion build up before installing a new water pump and thermostat. To achieve the optimal just like new surface, it's usually necessary to use a medium grit scotch brite pad and/or angle die grinder with a medium grit scotch brite conditioning pad. When the water pump mounting surfaces are thoroughly cleaned and smooth, gasket sealing agents are not needed! Sealing agents (RTV Form-a-Gasket silicones, aerosol adhesives or sealants) should NOT be used! It is important to note that no sealing compounds were used when mating the water pump to the engine block from the factory. The factory manual
makes no reference to using sealing compounds during water pump replacement. It is important to pay attention to and follow the manufactures installation instructions. Premature leaking from the water pump gasket mating area is almost always due to improper alignment during installation, mating surfaces not being prepared properly, or a sealing agent being used. Sealing agents (RTV Form-a-Gasket silicones, aerosol adhesives or sealants) vary in composition and intended usage. When used in conjunction with composite paper gaskets, they negatively affect the gasket's long-term ability to properly compress and perform the sealing function, rendering them ineffective. Appropriate gel like gasket sealing agents should only be used when there is severe pitting of the engine block surface and an even or smooth water pump mounting surface cannot be achieved. Double check all water pump mounting bolts for tightness. A loose or missing water pump or thermostat housing bolt can result in a leak and falsely attributing the water pump as defective.

Filling the Cooling System. Avoid Cooling System Contamination:

IMPORTANT: Read and follow the warnings on the antifreeze coolant bottle. Improper use can be harmful or fatal. Use only Audi VW G12 antifreeze coolant which was included in with the timing belt kit. These bottles contain coolant that is concentrated. You must dilute coolant that is labeled as concentrate! Mix 50% coolant with 50% deionized water to maintain the cooling system with a neutral PH. If deionized is not available, use distilled water. Never use or mix normal tap water with new coolant if at all possible. Tap water will contaminate the cooling system because tap water varies in PH and mineral content and depending on these factors, can create an acetic acid cooling system condition and adversely shorted the life of your new water pump and other cooling system components.

Water Pump Break-In Period:

All water pumps are inspected, and air pressure tested at the factory for any leaks. However, new water pumps do have a break in period. It is
not uncommon for a new water pump to have some seepage of coolant from the discharge hole below the water pump pulley shortly after starting up. This is because the unique seal material in the new water pump is designed to ‘bed in’ as the impeller shaft spins. Slight weeping or dampness from or around the discharge hole or cap is allowable for at least 100 miles after installation and should not be attributed as a defective water pump.


Mixing other brands of unauthorized antifreeze coolants with the approved G12 antifreeze coolant included in your new timing belt kit causes an adverse chemical reaction to G12 coolant, causing the coolant to gel and clot. This can damage the new water pump, plug the cooling system,
and weaken other plastic cooling system components (i.e. radiator, hose connections).


Be environmentally responsible. Dispose of the old anti-freeze coolant properly according to your local municipal laws and their guidelines.
Always read and follow factory service manual safety instructions and guidelines.
Always wear safety glasses and other safety items when performing the following work. Blauparts LLC. recommends that an Audi VW factory trained ASE certified technician install your parts.