Oil Leaks in Hydraulic Pumps and Motors

Pump X2P4902EPOA

Here are the most common causes

Have you noticed an oil leak from a pump or a hydraulic motor installed in your machinery? Identifying the cause of the leak is very important to understand how to intervene and then solve the problem as soon as possible.

Sometimes, in fact, it is sufficient to replace only an element of the component to eliminate the oil leak, in other cases it is necessary to change the entire pump or motor.

Let’s see what are the main factors behind the leak and how to eliminate it.

Most frequent oil leaks: causes and solutions

1 – Leaks due to a problem in the static seals of the pump or motor

In these cases, the leak is caused by a problem in the gaskets that provide a seal between the various elements that make up the pumps and motors. It may be a leak due to pressure spikes, which cause the gasket to extrude, or it may be a failure of one of the flange or body components.

2 – Oil seal leaks in unidirectional and reversible pumps and motors

This is the case when the leak occurs at the oil seal – rotary seals, which is a seal located at the shaft.

Here the causes of leakage can be different and depend on the type of component.

When the oil seal:

  • is installed on unidirectional pumps, the breakage – and consequent oil leak – depends either on excessive suction pressure or on the wrong direction of rotation of the pump (the pump was mistakenly made to turn in the opposite direction);
  • is installed on unidirectional motors, the breakage of the oil seal may derive either from excessive pressure on the motor exhaust or from the fact that the motor is fed from the wrong direction;
  • is installed on reversible pumps or motors, oil seal failure may result from either excessive pressure on the drain or even obstruction of the drain.

Solutions to the most common problems

When the oil leak is due to a broken static seal, the damaged element – the gasket or oil seal, as the case may be – must be replaced, because once broken, it can no longer be repaired.

If, on the other hand, the leak is caused by a break in the entire component, it is not enough to replace the seal; the pump (or motor) must also be replaced.

Other causes of oil leaks

So far we have seen what are the most common causes of oil leaks from pumps and engines.

However, there are also other reasons for leakage, for example, sometimes the defect is at the source. In this case, the leak occurs when the sealing system has not been properly installed. If this is the case, the element can break more easily and therefore leak liquid.

In other cases, the problem is excessive temperature. A very high temperature, higher than the seal can tolerate, can burn, dry out and wear out the component before its time.

Finally, there can also be a problem linked to the chemical incompatibility of the oil with the material that makes up the seal; this condition can also cause deterioration of the component before the end of its life.

In our catalogs you will find indications on the chemical compatibility of materials with the most common types of oil used to power hydraulic pumps and motors.

The characteristics of the fluid you use are not present in our catalog? Contact us for a more detailed check.

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