Have you found yourself struggling to know why your hydraulic pump has no pressure? Lack of hydraulic pressure brings operations to a standstill, and the core issues could lie with different components of the hydraulic system, from the pump itself to faulty valves.
CJ Plant is here with a guide on what to check for if your hydraulic system has no pressure, including the common signs and troubleshooting solutions. We are also here with expert support and inspection and repair services. Call us on 01527 870 793.
Common Signs Your Hydraulic System Has No Pressure
The first sign you’ll notice with no hydraulic pressure is issues in the system’s performance. Without enough pressure, components may stop functioning completely or move much slower than usual. Also, it’s common to hear unusual noises like whining, rattling or hissing, suggesting air leaks or pump failure. Read our blog post on why your hydraulic pump is noisy for more details.
There are several other signs to look out for, including:
- Cylinders failing to extend or retract – this typically means the system lacks the force needed to move hydraulic actuators, which often can be traced back to a failing pump or a drop in pressure.
- Lack of force or power under load – if your hydraulic system can’t perform under normal working conditions, it’s likely that pressure isn’t being built or maintained due to internal leakage or pump inefficiency.
- Overheating hydraulic fluid or components – overheating is a signal the system is overworking, which is a clear sign that pressure is being lost, and the pump is struggling to compensate.
- Foamy or milky fluid, indicating air or water contamination – pressure performance is reduced when moisture or air enter the system, often due to poor sealing or suction issues.
These problems could be caused by a range of faults, such as a failing hydraulic pump, worn-out seals, clogged filters or pressure relief valves stuck open. Spotting these signs early will help you discover the root cause of a loss in hydraulic pressure and prevent further damage and downtime.
Troubleshooting Your Hydraulic System
So, you may have noticed one or more of the signs indicating failing or no hydraulic pressure, whether components are overheating or aeration has occurred. Here’s what to check and how to troubleshoot.
1. Check the Hydraulic Fluid Level
Often, the culprit for no hydraulic pressure is low or contaminated fluid. The hydraulic fluid is stored in the reservoir, so check if the fluid is at the appropriate level and whether it looks foamy or milky. If this is the case, the pump won’t be able to generate pressure effectively. Top up if needed or replace the fluid entirely if it is contaminated.
2. Check the Pump Relief Valve
If the pressure relief valve is loose and stuck open, pressure will never build properly. It’s important to isolate the system before inspecting components like this, and the solution often just requires tightening the valve properly to the system’s specification.
3. Listen for Unusual Noises
Whining or knocking sounds suggest cavitation or aeration, both of which reduce hydraulic pressure and damage internal components. These usually point to air leaks or poor suction in the pump inlet or shaft seal.
4. Inspect the Directional Control Setting
Verify the position of the manual directional controls, as these can easily be changed unintentionally during maintenance or transportation. Also known as the Directional Control Valve (DCV), its role is to direct fluid to the right actuators, and if left in the wrong position, pressure won’t build even if the system is working. A faulty solenoid, manual lever or misaligned spool can prevent the valve from shifting correctly.
5. Check for Further Damage
It’s good to check for damaged valve seals, leaky hose connections, worn pump couplings, clogged filters and torn components. These seemingly small issues can lead to no hydraulic pressure or system failure over time. Damaged seals or loose hoses may allow air into the system, while clogged filters can restrict flow and cause the pump to strain.
If Your Hydraulic System Isn’t Regaining Pressure
If you’ve attempted some of these troubleshooting checks and your hydraulic system still isn’t producing the right amount of pressure, or none at all, it’s time to get your system inspected for repair. Having hydraulic specialists inspect the system is a good way to minimise the risk of further issues developing, resulting in a costly system replacement.
How CJ Plant Can Help
CJ Plant is a family-run company with over 20 years of experience in repairing hydraulic systems, including hydraulic pumps and hydraulic motors. If your system has no hydraulic pressure or is consistently failing to reach the right levels, get in touch with us and we’ll:
- Clean, strip and inspect the hydraulic system for FREE
- Create a detailed report on any issues found
- Provide a no-obligation quote for any repair work
- Repair your hydraulic system, replacing all damaged and worn parts
- Test your repaired system using our purpose-built test rig
Call us on 01527 870 793 and one of our friendly team members will answer your call, ready to help turn a system with no hydraulic pressure into a fully functioning unit.