Why water pump bearings are more important than you think

The bearing allows to reduce friction between moving parts. It may prevent a motion by controlling the vector and normal forces that bear on the moving parts.

That is, it supports and guides components that rotate with each other. It serves as a support, facilitating sliding while reducing the friction generated by transmitting movement of the motor rotation to the cooling circuit through the joint rotation of the shaft with the different pump impeller types.

Types of water pump shafts and bearings

Normally the water pumps are equipped with an integrated shaft. We can find different types of bearings depending on the type of load they must withstand (axial, radial, etc.) or the type of construction (ball type, roller type, etc.). There are two basic types of DOLZ water pump shafts and bearings:

• Roller-Ball: used when it is required to support a high load index for a limited construction space.
• Ball-Ball: used when high speeds are required and a lower load index is required.

Most bearings are made up of rings with races (inner and outer ring), rolling elements (balls / rollers) and a part called a cage. The cage is in charge of separating the rolling elements at equal distances, ensuring their position between the inner and outer race, which allows them to roll without any problem. The rings and rolling elements are made of steel and the cage in a thermoplastic material (type PA6.6)

Keep reading: How do water pumps with a thermal management module work?

Choosing a water pump bearing: Dolz’s expertise

To obtain the best conservation and the highest performance of the water pump, it is advisable that it has high quality components. In the same way that the different automotive parts evolve over time and with new technologies, axles and bearings have also been the subject of continuous innovation.

Among the possible bearing failures we find problems due to abrasions, wear, rust or jamming. Sometimes it is the result of an incorrect installation of a new water pump. Therefore, in order to guarantee the longest possible durability of our water pump, it will be essential to correctly fit it and ensure that the bearing supports the loads required for each specific application.

DOLZ Tip: Every precaution is good, therefore we recommend stopping the engine if excessive noise is detected (bearing damage), do not systematically fill the expansion tank with coolant if you notice that the water pump is leaking and go as soon as possible possible to your trusted workshop to locate and verify the damage caused.

Keep reading: Water pump leaking: how to solve this problem

Dolz provides shafts and bearings that meet the durability requirements defined by each vehicle manufacturer, suitable for each engine application, providing high reliability thanks to the quality of its materials and effective lubrication of the part.

La entrada Water pump shafts and bearings: best performance and efficiency se publicó primero en Industrias Dolz.

Function of the bearings in the water pumps

The water pump bearing has the function of holding the loads transmitted by the timing and the accessories belt or the gears and to connect the engine movement with the water pump impeller turning.

Normally, all the water pumps are equipped with integrated shaft. In this picture we can see a typical water pump bearing, composed by the outer ring, the bearing shaft, a row of rollers and a row of balls, all of them manufactured in stainless steel.

Types of bearings used in the automotive water pumps

We can find different types of bearings depending on the type of load they must withstand (axial, radial, etc.) or the type of construction (ball type, roller type, etc.). There are two basic types of automotive water pumps shafts and bearings: 

1. Roller-ball bearing, used when it is required to hold high radial loads.
2. Ball-ball bearing, used when there are required high speeds, radial load not very high and even a low component of axial load.

Industrias Dolz select the bearing more appropriate to each engine application to cover the high levels of quality and durability for the best performance and efficiency.

Typical bearing damages that are produced in water pumps

1.Excessive timing belt tension

There are vehicles that require a manual tensioning of the timing or the auxiliary drive belt.

The timing belt flat side letters use to have marked the belt trademark and belt technical characteristics. If the tensioning of the belt is very high, these letters disappear totally due to the excessive contact with the rollers or the blocking of one roller.

Also appears red coloring in roller and balls. This means that they are worn. Roller and balls race ways are also worn.

Bearing damages produce excessive noise. It is an indicator to stop immediately the engine to avoid engine breakdown.

2.Tensor roller incorrectly tightened vibrations

If the screw that fix the tensor roller to the engine become loose (it was not tightened at correct torque), then it will be produced belt vibrations and whips. Consequence of that, it will be produced an irregular wear of the belt flat side letters very similar to that appears in the bellow picture.

Bearing shaft race ways wear due to irregular loads applied to the water pump bearing.

3.Entry of coolant to bearing

If the water pump leaks between two dynamic seal contact faces, it will be produced an infiltration of coolant inside the bearing that will be removing the bearing internal protective grease. Without this grease, the bearing life will be reduced considerably because there will be produced a contact metal-metal of the bearing elements.

Here an example: Coolant has infiltrated inside the bearing removing it internal protective grease.

If you detect coolant loses by the water pump exhaust hole, you must stop the engine and go to the mechanic.

4.Irregular function of other engine components

The water pump is connected to other engine parts by the timing belt, the auxiliary drive belt or gears. If any of these elements don’t work properly, it should generate whips and vibrations that will be transmitted to the bearing, reducing considerably its service life.

Maybe you are interested: …All in Dolz. In-house production end to end

Dolz water pump shafts & bearings: your safety choice

The water pumps manufactured by Industrias Dolz include bearings that have same quality and service life than original equipment. 

For long bearing life should be followed these requirements: 

– Tensioning the timing or accessories belt according OE specifications. 

– To check that the screw that fix the tensor rollers to the engine is tightened to the correct torque.

– Repair the engine parts that are damaged (specially if they are connected to the water pump by the timing or the aux drive belt). 

And also it is needed to have the following precautions: 

– Stop the engine if excessive noise is detected (bearing damage). 

– Do not refill the expansion vessel with coolant in a systematic way if it is observed that the pump leaks, go to the workshop to verify the damage.

Dolz’s water pumps have their water tightness rigorously checked in a calibrated and extremely precise automatic leak detection machine. This allows us to hold a guaranteed rate that is less than a 0.05% in all our aftermarket car parts.

For further information on any of our product lines, receive commercial information or technical product specifications (including assembly notes), CLICK HERE.

La entrada Water pump bearing damage and failure se publicó primero en Industrias Dolz.