How to tell if a hydraulic pump is running well

Articles - Education

Hydraulic PumpFrom experience we can say that in general, the hydraulic component on which the greatest responsibility for the functioning of the hydraulic system of a machine is the Glossary Link pump, or pumps.

This does not mean that it is the most important, is generally the one that works longer, and because of its construction is highly dependent on the good care of the oil and a good filtration.

All hydraulic systems follow a logical sequence of operations determined by the type of components within the circuit and how they are interconnected. Without going into details of how they made the detection of faults in the machine, say we have a suspicion that the pump may be malfunctioning.

Before you begin, you must obtain as much information about the system and in particular about the pump:


Type of prime mover (electric, hydraulic, diesel, gasoline, etc..), Power and rotation speed or RPM. The temperature at which the system works.

Type of pump (gear, vane, Glossary Link piston, etc.) Glossary Link Flow to supply without Glossary Link pressure, flow at the Glossary Link working pressure, maximum allowable pressure. Diameter recommended by the manufacturer for the suction and discharge, to compare with the actual.

There are suction Glossary Link filter? , What type (internal, external, microns), bypass ( Glossary Link valve opens when the filter is clogged).

Tank height with respect to the pump (over level or below). Oil level in the tank.

Needless to say, all this information will help you to interpret the test results, to avoid doubts.

Using a flow meter, a Glossary Link pressure gauge and a pressure Glossary Link relief valve, we must do the following arrangement:




How to test a pump




By isolating the pump discharge from the rest of the hydraulic system, turn on the Glossary Link motor and let the pump sends the flow through the Glossary Link flowmeter, keeping open the relief valve to the tank. In this way we can meassure the pump flow without any load, which must be equal to that suggested by the manufacturer under no pressure.

Then we start closing the relief valve and we should see how the needle in the pressure gauge rises. When we reach the working pressure, we read the flow and compare it with that suggested by the manufacturer. The difference between the flows with and without pressure gives us an idea of ​​the volumetric Glossary Link efficiency of the pump. Values ​​below 80% are considered low and the pump should be replaced.

Now look at other factors.

If at the time of taking the first flow, the value is less than the one suposed to be with no load, take into account that this may be because the pump is sucking air through the suction or through the shaft seal. From the amount of air that it is sucking will depend how low the flow will be.

Another problem that can make the reading of the flow without pressure is lower is due to a Glossary Link restriction in the suction of the pump, causing an excessive Glossary Link vacuum in the suction generated by the phenomenon known as Glossary Link cavitation. This phenomenon can be confirmed with a vacuum gauge placed at the inlet of the pump as close as possible.

Summary. If the pump does not have problems with the suction, such as Glossary Link aeration or cavitation, the flow readings have 100% certainty about the status of the pump. If we have doubts with the suction, these problems must be solved before measuring the flow at the pump for maximum accuracy.

Would you like to try out ipage hosting, they provide reliable green hosting service.

Hydraulics Knowledge POLL

Is the pressure a result of the flow?
Hydraulic Calculations 2.0
Hidraulic Calculations 2.0

BLOGS Latest Posts


04.05.2013 19:25 0 0

Çelebi Hidrocel ® Axial Piston Pumps, Axial Piston...

Memo63  →  Motor Hidraulico vs Motor Electrico

03.14.2013 02:14 1 0

Hola todos Espero alguien pueda ayudarme. Deseamo...

Hydraperm  →  Hydra-Perm-Co Ltd - PERMCO UK, European & Middle Eastern Distributors

08.29.2012 18:15 2 0

// Hydra-Perm-Co Ltd is an international...

nefacio  →  Consulta sobre cañería de salida de bomba

08.24.2012 00:23 1 0

Hola, tengo una consulta sobre la elección del dia...

kobra  →  Bienvenidos a KOBRA Paintball fields

07.22.2012 03:30 0 0

// Puede visitar nuestro sitio en Face...


06.16.2012 08:10 0 0


jneschii  →  Buscando un motor hidráulico que funcione eficientemente desde baja velocidad.

06.06.2012 16:37 3 0

//   Hola, buenos días. Muchas gracias...

BLOGS LatestComments

Motor Hidraulico vs Motor Electrico

Buenos dias, Para empezar, es mejor saber cual es ...


Latest Hydraulics News


Recent Content Added

Copyright © 2008 - 2020 Hidraulica Practica. All Rights Reserved.

Joomla Templates designed by Joomla Hosting