What To Do With Noisy Hydraulic Cylinders

If you’re hearing high pitched or unusual noises coming from your hydraulic system, it can usually be traced back to the hydraulic cylinders. Although you can expect a certain level of noise from most machines, when this noise reaches quite a high level, it can create other problems, particularly in the workplace.

Workers may begin to feel fatigued from the noise, be required to wear some additional form of hearing protection, or may develop other problems. It is for these reasons that it’s useful to know how to prevent certain issues and how to deal with noisy hydraulic cylinders, ultimately helping to get your system down to a more reasonable noise level.

What causes noisy hydraulic cylinders?

One of the main culprits for causing a hydraulic cylinder to squeal or make noise is the presence of aeration. In other words, this is a leak in the system that typically occurs on the suction side of the component. The leak creates a squealing or whining noise to spread along the frame of the hydraulic system, but it can often be traced back to the cylinder itself.

This aeration can cause a degradation of the hydraulic fluid, causing substantial damage to other components of the system due to overheating and reduction of lubrication.


Another abnormal source of noise in a hydraulic system which you may be hearing is a result of cavitation. Although this issue is usually associated with motors and pumps it can also happen in hydraulic cylinders. Cavitation can happen in pump systems with high vacuum conditions, whereby the volume of fluid required by a component in the hydraulic circuit is greater than the amount of fluid that’s being supplied. As a result, the absolute pressure in that component of the circuit falls beneath the vapour pressure of the hydraulic fluid.

This can cause vapour cavities to form in the fluid, which implodes when compressed, creating a certain noise that sounds like knocking. Unfortunately, the noise is just the start of the problem, as cavitation can lead to erosion of the metal, and can even lead to a mechanical failure of the hydraulic system itself.

Preventing Cavitation

Temperature control can help you to prevent cavitation from occurring in your hydraulic systems. A high level of care needs to be taken to keep the hydraulic fluid temperature as close to an ideal operating level as possible at all times. You may find that insulating your hydraulic pipes against direct sunlight can help in this regard, particularly when operating in warmer climates.

Preventing air from entering the system can also help to prevent cavitation. Make sure that the relevant components are bled properly after being filled to release trapped air from the system. When you’re adding fluid to the system, make sure that you do it lightly as if you agitate and splash the fluid you may be allowing air to be entrained along with the hydraulic fluid.

Fixing Noisy Hydraulic Systems

Hydraulic cylinders aren’t always the ones to blame when it comes to unwanted noise levels from your hydraulic systems. It’s best to always take note of the hydraulic pump intake lines, making sure that they are in solid condition and that the fittings and clamps are all in a tight position. The problem with flexible intake lines is that over time they can begin to become porous. Make regular checks on these lines and if you suspect that one of your intake lines may be at fault you need to replace the line.

If you find that the fluid level in the system’s reservoir is below normal, make sure to fill it to the appropriate level. If the pump shaft seal appears to be leaking, you’ll need to replace this, as in some cases air can enter the pump through the shaft seal and create a noise.

Vibration-Dampening Mounts

One particularly effective way of dealing with noisy hydraulic systems is by utilising vibration-dampening mounts. You are able to mount the motor-pump assembly to a different subframe with these helpful mounts. The same goes for when mounting this subframe to the actual power unit. Many people also deploy other types of industrial soundproofing materials, making sure that they encompass the hydraulic system in them. This can be helpful in reducing the amount of noise that you are hearing.

Always Source Quality Hydraulic Cylinders

To avoid problems with hydraulic cylinders in the future, it’s imperative to always invest in high-quality parts and hydraulic systems that are built to last. The Eaton Vickers hydraulic cylinders are well renowned around the world for being cost-effective and reliable products built for a variety of different purposes.

If you are struggling with noisy hydraulic cylinders or systems in general, it’s best to contact the manufacturer of the product. They have more than likely encountered a similar problem and may help to offer a number of potential solutions on how to deal with the unwanted level of noise that the component is creating.