Replacing Hydraulic Pump

Replacing Hydraulic Pump - All You Need to Know

Sometimes replacing a hydraulic pump due to failed operation can be a difficult task. Improper replacement procedures may result in damaging the whole hydraulic system. Several reasons may cause your hydraulic pump to fail. Some failure requires full replacement while others do not. If you notice that your hydraulic pump is not working like before, you should troubleshoot it immediately. Do not wait until the entire system fails. This will result in costly downtime and repairing can be very time-consuming. What are the causes of hydraulic pump failure? What are the signs that the hydraulic pump needs to be replaced? Do you need to replace your hydraulic pump frequently? Is changing a hydraulic pump costly? All these questions will be answered in this blog post. Keep reading to learn more.

What are the Causes of Hydraulic Pump Failure?


Contamination of the hydraulic fluid is one of the most common reasons why hydraulic pump fails. Hydraulic fluids can get contaminated when particulates are introduced into the system by the valve or rod. Fluid contamination can corrode hydraulic pump components and may cause failure operation.

Excessive Pressure
Excessive Pressure

Hydraulic pump is designed to handle a specific safe range of pressure. The pump can be damaged when used for applications with pressure higher than its capacity to handle. Eventually, your hydraulic pump will fail and stop working. It can even result in explosion when used with uncontrolled excess pressure.

Low Quality Hydraulic Fluid
Low Quality Hydraulic Fluid

The right amount of fluid viscosity and mineral content is necessary for higher-pressure system applications. Too much viscosity will result in cavitation while too low viscosity of the fluid can increase friction and heat level. These results can be dangerous and cause risk of pump damage.

Excess Temperature
Excess Temperature

Fluid can degrade and seal can be damaged when the pump is used for applications with temperature higher than 180°F. Cavitation, internal leaks, or airflow obstruction in the reservoir can cause overheating.


Internal damage and improper sealing can cause leakage. If not treated as soon as possible, it may contaminate the pump and compromise its performance.


Cavitation can erode the metal in the hydraulic system. This can cause fluid contamination and may result to pump failure.

What are the Signs that Your Hydraulic Pump Needs to be Replaced?

During your regular inspection, you should look out for these signs:

Increased noise during operation. Noise during operation is natural for all mechanical machines and actuators. However, loud noise such as knocking or banging is not usual. It may be a sign that your hydraulic system is contaminated or experiencing aeration.

High temperature. If you notice that your hydraulic system has temperature higher than 180°F/82°C, it is a sign that of residue buildup. This problem must be taken care as soon as possible since temperature changes can quickly damage a hydraulic pump.

Slow functioning. Does your hydraulic system function becomes slower compared to its usual operation? It may be a sign of possible internal leaking.

How Can You Replace a Hydraulic Pump?

There are 11 ways to replace your hydraulic pump.

  1. You should find out the main cause of pump failure.
  2. Take out the failing mechanism of your pump.
  3. You should also retract all your unit rods.
  4. Remove the tank’s fluid.
  5. Clean the tank using diesel fluid while power is on. wipe or remove any residue after flushing.
  6. Install a new filter.
  7. Connect your new pump.
  8. Refill the tank with new oil. Make sure to use the appropriate oil grade to prevent pump failure. Maintain the level of oil supply and ensure it does not drop too low.
  9. Turn the handles of the control valve in an upward position. This will prepare the circuits for the new oil.
  10. All lines including the liquid motors and cylinders should be connected excluding the rod end. Turn all the circuits on until you see the bottom of the cylinder. This will help the contaminated oil to flush out from the cylinder easily. Do this process again and again as necessary.
  11. The final step is changing the filter.

If you don’t have any experience in changing hydraulic pump before, we recommend that you consult an expert and professional.

How Frequent Should You Change Your Hydraulic Pump?

Hydraulic pumps can last for many years. However, its longevity also depends on how often it is used. Most manufacturers of hydraulic pump will specify the component’s hours or cycle before you replace them.

Its life expectancy also depend in another factor – the preventative maintenance such as daily and annually.

Daily Preventative Maintenance

-Check the oil level

-Check the pump’s temperature

-Check whether there is contamination

-Inspect the system ensuring there are no leakage


Annual Preventative Maintenance

-Check all the components in your system

-Inspect the whole system

-Change your hydraulic oil


Is Changing Hydraulic Pump Costly?

If done by a professional, changing the hydraulic pump, including all the necessary parts and labor, will cost around $1500. However, the exact cost will depend on some factors.

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