A noisy hydraulic pump may need repairing or replacing, but these noises happen for a wide range of reasons. These noises might be excessive vibrations, erratic hissing or whistling, knocking, rattling and other irritating, hard-to-ignore sounds.
These noises are not just irritating and cause disruption; they are likely an indicator of something more serious. CJ Plant is here to detail the causes of noisy hydraulic pumps and provide troubleshooting tips on what to look for.
If you have a noisy hydraulic pump and require an inspection to get to the problem, call us on 01527 870 793.
Common Causes of a Noisy Hydraulic Pump
Cavitation – Noise Type: Whining/Screeching
If your hydraulic pump is producing a whining or high-pitched screeching sound, cavitation is likely occurring. Cavitation happens when the pump’s fluid pressure drops and causes air bubbles to form, which then implode. You may also hear severe rattling when this occurs, and this issue will lead to increased wear, erosion of components, contamination and damage to seals.
Aeration (Air in the System) – Noise Type: Loud Knocking/Banging
Aeration, or air contamination, is a serious issue which causes loud knocking and banging noises. This occurs when air enters the hydraulic fluid, typically through the pump’s inlet or shaft seal, and will cause similar damage to cavitation but on a more erratic scale. The knocking and banging noises occur as pockets of air compress and decompress.
The noises can be similar to cavitation, including whining, so it is not uncommon for these two issues to be confused.
Misaligned Couplings or Internal Wear – Noise Type: Grinding/Roaring
If your noisy hydraulic pump is producing grinding, roaring, rattling or other metallic sounds, it could indicate misaligned couplings or internal wear. Most likely, you’ll also see and hear strong vibrations due to components becoming worn or the misalignment causing harmonic imbalance. It can be difficult to know exactly where misalignment or internal wear occurs, so if you hear these types of noises, a full strip and inspection will be needed.
Contaminated or Degraded Hydraulic Fluid – Noise Type: Buzzing/Clicking
Hydraulic fluid plays a crucial role in dampening noise and maintaining smooth pump operation. If the fluid is dirty, degraded or contains debris, you may hear buzzing, clicking or irregular pitch changes during use. Contaminants reduce lubrication and can damage internal components due to overheating, leading to louder operation over time.
Relief Valve Issues – Noise Type: Whistling/Hissing
A noisy hydraulic pump will produce whistling and erratic hissing sounds due to issues with the relief valve. The relief valve is designed to maintain the pump’s pressure at a safe level and control the flow of hydraulic fluid. The relief valve can become loose, causing a consistent release of air, or be set too low, resulting in irritating sounds. Relief valve issues normally stem from excessive heat, slamming of actuators and frequent stalls.
Troubleshooting Tips
Here are some troubleshooting tips for noisy hydraulic pumps – these are quick checks you can perform yourself before calling a professional.
- Listen to the type of noise – different pump problems will have different noises, so listen if it’s whining, knocking, clicking or hissing to help you find the root cause
- Inspect for leaks – check around hoses, seals and connections for signs of air getting into the system
- Check fluid levels – low hydraulic fluid could point to cavitation or aeration, so it’s best to see if the pump reservoir needs topping up
- Look at the pump speed – if the pump seems to be working harder or faster than usual, it could be running beyond its designed limits
- Tighten all loose connections – go around the pump and tighten any loose valves, fittings or pipe clamps that vibrate against each other
- Keep up with maintenance – prioritising regular maintenance and inspections for your hydraulic pump is often the best way to ensure any unnecessary noises are kept to a minimum and that the pump functions as it should
When to Contact a Hydraulic Repair Company
It’s always best to contact a hydraulic repair specialist if you have tried troubleshooting the issue yourself, but to no avail, or if you are ever unsure what the issue with the pump is.
If you find yourself in either situation, CJ Plant is just a phone call away to provide expert assistance. Speak to one of our team and we’ll quickly organise a no-obligation quote. We then perform a free inspection to locate the root of the problem. From there, we can provide hydraulic pump repair, transforming your noisy hydraulic pump into one that’s back to OEM specification.
Get in Touch With CJ Plant
If you are having issues with a noisy hydraulic pump, CJ Plant and our family-led team are here with over 20 years of experience to locate the problem and provide long-lasting repairs. Enquire with us today or call us directly on 01527 870 793.