Hydraulic Motor Repairs

We have a range of motor test facilities on-site at our repair shop, which allows us to get into the nitty-gritty of the parts to identify and fix the issue fast.

We’re able to repair (or replace with genuine parts if deemed necessary) both the hydraulic pump and motor of most leading manufacturers. Our fault-finding service is second to none, and our engineers are all experienced with a range of common and uncommon hydraulic motor problems – meaning we can offer you fast results.

Hydraulic motors are built to last. They might hit snags during their operation, but they shouldn’t need replacing often. However, with the best will in the world, we can’t always fix the hydraulic motor if the damage is extensive or the issue is too far gone.

We can offer new units, new equipment, or new parts as required – but know that our highly skilled engineers will always try to repair your hydraulic motor before replacement is looked into. This will be cheaper for you in the long run, and we’re all about cutting costs for our customers.

Maintaining your hydraulic motors is a matter of scheduling regular checks.

• Hydraulic fluid checks: Regularly test the hydraulic fluid levels and maintain a proper level that is clear of contamination. Sample the fluid for any changes in colour and odour. If the water takes on a milky hue, then it may be contaminated.
• Change the filters: Filters keep pollutants that will lead to some of the more common failures of a hydraulic motor. Considering it’s not easy to spot contamination when you see it, it may be a good idea to simply have filters on hand and schedule their changing.
• Replace seals: Seals are responsible for keeping the motor from leaking. Over time they will degrade, especially if contamination has been in your motor for any period of time.
• Hoses and fittings: All hoses and fittings should be checked for damage. This could be from fraying, stretching and kink. Anything with dents, or signs of corrosion, needs to be replaced. On top of that, ensure couplers are clean and secure any fittings that can be.

The temperature needs to be regulated within a motor to ensure its smooth function, and to avoid the following: 

• Fluid Thickening – Viscosity is the resistance a liquid has to part from itself. For example, when water gathers on a ceiling and drips slowly. This is gravity pulling away water. Low temperatures can increase the resistance of the hydraulic oil within the pump, leading not only to productivity issues but also to cavitation – more on this in the next FAQ. 
• Fluid Thinning: Meeting a certain heat threshold can cause a motor’s fluid to thin. This makes lubrication difficult, and it also makes escape in the form of leaks much easier. 
• Fluid Oxidisation: Oxidisation is the process of a substance being mixed with oxygen. Whilst heat can cause fluid to thin, as explained in the last example, extreme heat can cause oxidisation, thereby thickening the fluid. Sometimes it becomes so thick that it blocks the flow of water, which also causes a buildup of heat due to the motor’s inability to dissipate and regulate its temperature. 

Both air and water can pollute a hydraulic motor. The following are the three different types of contamination that can destroy a piece of machinery. 

• Cavitation is the process of the separation and implosion of the dissolved air within hydraulic oil. The implosion results not only in a distinct whining sound but also causes damage to the pump over a period of time. This damage can also spread to other components within the motor. 
• Aeration is the process of air invading the motor from the outside. This is almost always due to some sort of structural damage on the motor, such as loose connections, or even a leak. The contamination makes a knocking sound. 
• Water Contamination is a fairly basic process. It relies on there already being structural damage to the machine. If the water receives too much oxygen (oxidation) or falls in temperature to the point of freezing, it will degrade the inner components of the motor over time. The fluid will then take on a milk-like look.

All hydraulic units will rely on hydraulic pumps and hydraulic motors to function. The hydraulic pump uses an electric motor to drive it, and the hydraulic motor uses pressurised fluid to turn the output shaft, where the next stage of the hydraulic system picks up.

That might sound confusing, but the point is that the two rely on each other – where one breaks, another can’t perform, which is why hydraulic pump repairs and hydraulic motor repairs are often needed at the same time.

But not always. You can require a hydraulic motor repair without the need for a hydraulic pump repair – but our testing service and hydraulics servicing will take their interconnectedness into account, allowing us to identify the issue that’s stopping your hydraulics system from working.

From there our hydraulic service engineers can fix your issue and return the parts to you quickly, so production isn’t impacted for too long.

Without a fully functioning swing motor, excavators can experience slow rotations or even stop-start movement. If the structure doesn’t rotate or complete a full swing, it could be time to carry out a swing motor repair.

Other symptoms include overheating, hydraulic leaks and grinding or knocking noises, which can be caused by internal wear and tear, such as damaged seals or cracked internals.

If you notice any of these symptoms, it’s best to stop operations before further damage is made to the system, which can also put health and safety at risk. If not performing correctly, swing motor repair should be carried out to ensure safe and compliant processes are carried out. Repairing swing motors early is essential for extending their lifespans.

Signs that a hydraulic motor is underperforming include decreased performance and efficiency, and slower operating speeds. Other signs include.

• Fluctuations in Speed & Low Power/Torque
• Reduced power or slow operation
• Oil Leaks
• Overheating and unusually high working temperatures
• Jumpy or erratic movements

When properly maintained, hydraulic motors can last for many years. The lifespan of hydraulic motors is usually measured in operating hours rather than years, as they’re influenced by factors like operating conditions and maintenance.

To ensure hydraulic motors last longer, maintain proper fluid cleanliness and get regular maintenance checks to flag any issues early. 

If you need a hydraulic motor repair, it’s recommended to work with a professional to ensure your repair is in expert hands. Attempting to repair the damaged motor yourself can sometimes cause more damage if reassembly is done incorrectly.

Here at CJ Plant, we offer a range of hydraulic repairs, including piston motors, gear motors, and swing motors. Simply get in touch with our team for a free strip and inspection.

Instead of fully replacing your hydraulic motors, they can be rebuilt. In many cases, this can be a cost-effective alternative to replacement, especially for specialised parts.

Rebuilding involves taking apart the motor, cleaning all components and replacing worn parts. Rebuilding also ensures a faster turnaround time often avoiding long lead time for new motors.