Problems with water pumps are not an unknown phenomenon. Unfortunately the causes can be many, which makes the issue complex. Nevertheless we will in this article try to explain the causes of errors in the water pump and in the cooling system.
The water pump
The market for water pumps is characterized by large differences in prices caused by huge differences in quality. But which factors determine the prices? The answer is simple: Quality components and quality assurance.
Components
Especially the bearing and the mechanical seal are important for the lifetime of the water pump. For this reason Triscan’s water pumps are fitted only with bearings of OE quality, which means that they are hardened at different temperatures inside and outside. They must be hard on the side facing the rollers/balls and softer on the side facing the pulley and the impeller. The seals are also of OE quality and made of a special material (SIC / graphite) which makes them more resistant to contamination in the cooling water. The most common wear indicator is a leaking seal resulting in water penetrating into the bearing, which would ruin the water pump.
Example of contaminated and thus leaking seal
Some car manufacturers are now using impellers made of PPS (polyphenylene sulfide) – a hard plastic material which is lighter than metal resulting in a smaller load on the bearing and hence a longer lifetime. But it is also a fragile material, which is less shock resistant. At the request of several customers we have kept the metal impellers on some specific water pumps where the original have been changed to PPS, among others some VW numbers. Other components – and especially their tolerances and the way they are assembled – are also important for the lifetime of the water pump. The correct tolerances of the bearing, pulley and impeller are important for the correct assembly and the final quality of the product. Assembly at too high or too low pressure may cause problems. For this reason the production process is 100% controlled from start till end.
Example of damaged bearing due to leaking seal
Quality assurance
There are huge demands on the quality of water pumps, and in their efforts to sell a product at a very low price many manufacturers in the market do not meet the automotive quality standards – TS16949. At Triscan we do not want to compromise on quality! Therefore, we only market water pumps meeting the TS16949 standard. All the Triscan water pumps are tested for leakage, lifetime etc – on test equipment specified by the car manufacturers. In addition to these tests the Triscan water pumps are in many cases also tested by the Danish Technological Institute, e.g. load and torque tests.
The water pump as a system component
In most engines the water pump is also integrated in the timing belt system (besides the cooling system). In both systems the water pump is a vulnerable component where several factors play a role for the optimal working of the water pump.
The timing belt system
The lifetime of the water pump is significantly reduced if the replacement of the belt, belt tensioner and pulleys is not carried out 100% correctly. The most common errors are caused by excessive tension of the belt or incorrect installation of the water pump, resulting in the pulleys not being in line (which in both cases results in uneven load on the water pump bearing and thus in increased wear and tear). So using the best OE components in the timing belt system is not necessarily a guarantee for a long lifetime of the water pump. Eventually also the OE construction of the water pump may be too weak – in those cases even a perfectly manufactured and installed water pump and timing belt kit cannot compensate for a bad OE design.
The cooling system
The quality of the coolant is also important for the lifetime of the water pump. Incorrect mix between coolant and water causes calcareous deposits. Calcareous deposits in the cooling system works as a grinding compound and may damage the seal of the water pump.
Example of the result of contaminated coolant
The result is a leaky seal which may cause a leakage and penetration of water into the water pump bearing which will be damaged. In connection with the installation of water pumps many workshops do not use only the supplied gaskets / o-rings, but also adds liquid/packing seal in so large quantities that parts of the seal end up in the cooling system. Also this kind of impurities can destroy the water pump seal resulting in a damaged bearing. As a basic rule always empty the cooling system for liquid, clean the cooling system and avoid the use of liquid/packing seal and do not reuse the coolant.
Example of incorrect use of liquid gasket
Using a Triscan water pump and complying with the above guidelines will ensure optimal conditions and thus a long lifetime of the water pump.