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Airtex Discusses Common Water Pump and Timing Belt Fitment Problems

By autotech-nath on June 25, 2021

One of the world’s largest automotive pump manufacturer, Airtex, is raising common fitment problems technicians can make when replacing water pumps and timing belts and provides advice on how to avoid them.

Nowadays, engines are increasingly complex and, due to the wear and tear components suffer during their normal use, it is essential for technicians to carry out preventive maintenance checks, as stipulated by the manufacturers themselves, in order to extend its life span to the maximum without losing any performance.

One of the most important procedures a technician can undertake is timing belt and water pump replacement. Airtex provides a kit that includes all the elements necessary to complete a quality replacement that will maintain its correct function within the engine.

In most vehicles, the water pump is still driven by a belt and from Airtex’s experience and knowledge, following a
few simple steps when changing them will prevent serious subsequent damage. The essential aspects to consider when carrying out replacement are essentially the cleanliness of the rigid components, as well as the pump housing and cooling system, and the correct tension of the belt.


Cleaning is something that is sometimes omitted in repair and maintenance processes, but it is highly recommended to do it thoroughly since the belt, crankshaft and camshaft, water pump, tensioners, idlers, etc, are continuously spinning. Foreign bodies that end up between these moving parts can cause premature wear to the drive system and cuts in, or breakage of, the belt and consequently serious engine damage.

In addition, this area can be in contact with corrosive liquids, such as oils, solvents and coolant, which can rapidly deteriorate and rust the drive components. In this case, not only should

the area be cleaned, but it is also necessary to ensure that there are no fluid leaks, which, if found, should be repaired immediately.


The belt tension is something of vital importance that manufacturers themselves emphasise in their repair manuals, including specific procedures with the steps to follow during the tensioning process. Generally, these start with the locking of the crankshaft and camshaft, since the movement of the pistons and the valve openings and closures have to be perfectly synchronised for optimum engine function.

All the elements of the drive system must be replaced, including where driven by the timing system, the water pump. Then the new belt must be tensioned correctly. Although it is increasingly common for manufacturers to incorporate automatic tensioners that maintain the correct tension of the belt, it is however, very important to follow all assembly steps specified.

An over-tensioned belt can cause deterioration and premature wear, affecting the bearings in the tensioners, idlers and water pump, and even belt breakage. Equally dangerous is a belt with insufficient tension, since the slack produces a buckling motion, which causes similar faults in the belt and the rest of the components.

It is also necessary to check the alignment of other components, such as the camshaft pinions, crankshaft or injection pump, as this could cause a forced tightening movement of the belt, capable of damaging tensioners, idlers or even the water pump.



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