• Skip to primary navigation
  • Skip to main content
  • Skip to primary sidebar
  • Skip to footer

Mobile Hydraulic Tips

Mobile Hydraulic Tips focuses on pumps, fittings, valves, manifolds and other products and news in the Mobile Hydraulics industry.

  • Hydraulics Blog
  • Industry News
  • Engineering Basics
  • Components
    • Cylinders
    • Fittings / Couplings
    • Pumps / Motors
    • Sensors / Gauges
    • Valves / Manifolds
    • Related components
  • Design Guide Library
  • Advertise
  • SUBSCRIBE

Four signs your hydraulic pump needs to be rebuilt

October 13, 2022 By Mary Gannon

Share

Contributed by Tracy Jones, Director of CJ Plant Maintenance

The challenge with hydraulic pumps is that they are often neglected until something goes wrong. You wouldn’t be blamed for not knowing how often you need to service your hydraulic pump or how often it needs maintenance. However, some common signs indicate when your pump needs to be rebuilt instead of just serviced. If any of the following statements apply to your pump, then it’s time for a rebuild.

A technician works on a hydraulic press. Image Source: FreeImages
A technician works on a hydraulic press.
Image Source: FreeImages

1.     Your hydraulic pump is noisier than normal

The noise could be from the internal parts rubbing together or from hydraulic fluid rushing through the system. Perhaps it is worn out or there is too much load on the pump. A worn-out pump will have higher internal friction than a new pump, causing extra noise. In addition, a worn or damaged pump may not be able to handle a high load without heating up. This will make it vibrate more and increase pump noise. If you hear humming or grinding noises from your pump, it is important to investigate the cause immediately because the cause could be very serious.

2.     There is a lack of fluid in the tank

First, you should check the fluid level when your machine is off. If the fluid level is below the normal mark, the pump may not be returning all the fluid to the tank. If you notice that the fluid level is at the top while the machine is off, it could be that the pump is not drawing enough fluid. If the pump is operating normally and the fluid level is low, there may be a leak in the system.

3.     You notice a strong odor coming from the pump

A hydraulic pump is enclosed, and many of the internal parts are made of metal. The metal parts are subject to corrosion and some wear. This means that your pump can leak hydraulic fluid from time to time. When fluid leaks from the pump, it will smell, and there will be a puddle of fluid on the floor, where the pump is located. A bad smell coming your hydraulic fluid can be an indication of dirty, contaminated oil and failure of the internal pump components.

4.     The output pressure of your pump is erratic

When a pump is new, it uses some of the fluid in the system to build up pressure. As the pump ages, it uses more fluid. If the pump is running but the pressure is lower than normal, it could be a sign that the pump is worn out. When you are operating your machine and the pressure drops, it is best to stop the machine and investigate. If the pressure is high, but well below normal, it could be that the pump is not drawing enough fluid and the pressure is high because there is too little fluid in the system.

Conclusion

Whatever the reason, if your pump is worn out, it is time to rebuild it. A worn-out pump will not be able to do the job it was designed to do. It may be unable to provide the necessary pressure or flow rate, or it may just fail when you need it most. When your pump is worn out, you need to have it rebuilt or replaced. A worn-out pump is also a safety hazard because it may not be able to handle the necessary pressure or flow rate.

CJ Plant Maintenance
cjplantmaintenance.com

 

Image Source: FreeImages

 

CAPTION: A technician works on a hydraulic press.

 

 

You may also like:

  • Cavitation-iStock_000001804329Large
    Nine reasons why your pump runs slow
  • Permco-hydraulic-pump-gear-manufacturing-with-lubricating-oil-
    Building a world-class hydraulic pump
  • Kraft-fluid mobile hydraulic repair
    Four tips for selecting the right mobile hydraulic repair

  • The basics of hydraulic pump design
  • Wooster-Hydrostatics hydraulic repair
    Hydraulic repair: Quality, cost and value

Filed Under: Components, Mobile Hydraulics Blog, Pumps / Motors Tagged With: cjplantmaintenance

Primary Sidebar

Fluid Power Design Guides

fluid
“mht
EXPAND YOUR KNOWLEDGE AND STAY CONNECTED
Get the latest info on technologies, tools and strategies for Fluid Power Professionals.

Fluid Power World Digital Editions

Fluid Power World is written by engineers for engineers engaged in designing machines and or equipment in Off-Highway, Oil & Gas, Mining, Packaging, Industrial Applications, Agriculture, Construction, Forestry, Medical and Material Handling. Fluid Power World covers pneumatics, mobile hydraulics and industrial hydraulics.

Footer

Mobile Hydraulic Tips

FLUID POWER WORLD NETWORK

  • Fluid Power World
  • Hose Assembly Tips
  • Pneumatic Tips
  • Sealing and Contamination Tips
  • Fluid Power Distributor Lookup

MOBILE HYDRAULIC TIPS

  • Subscribe to our newsletter
  • Advertise with us
  • Contact us
  • About us

Copyright © 2025 · WTWH Media LLC and its licensors. All rights reserved.
The material on this site may not be reproduced, distributed, transmitted, cached or otherwise used, except with the prior written permission of WTWH Media.

Privacy Policy