Hydraulic motor failures tend to worsen gradually until the whole motor fails. The sooner you recognise damage, the easier it will be to fix the hydraulic motor. For plant operators, construction companies, farmers and forestry workers, hydraulic motors are vital. They are the driving force of excavators, loaders and harvesters. If you operate hydraulic machinery, learn the early warning signs of failing hydraulics to avoid costly repairs or replacements.
The Role of a Hydraulic Motor
A hydraulic motor is the component that converts energy into mechanical power. They work in connection with hydraulic pumps, which use engine power to drive hydraulic fluid into the motor under pressure. This exerts force on the pistons or gears inside the motor to create rotation and produce torque that powers the mechanical actions such as boom and bucket operation in excavators.
There are various types of hydraulic motors to suit different applications. These include:
- Piston motors, which provide high torque at low shaft speeds
- Variable motors offer a range of speeds
- Gear motors, which withhold lower pressures than piston motors
- Torque motors for slow speeds and high torque applications.
Hydraulic Motor Failing Signs
When a hydraulic motor fails completely, machinery stops working and repairs become expensive. By recognising failures in these complex systems early, you can extend the lifespan of components with a timely hydraulic motor repair.
1. Loss of Power
When hydraulics are worn or damaged, machinery struggles to deliver the usual mechanical power. You may notice your loader or excavator struggles to lift the same loads it once did. The overall efficiency of the hydraulic system is failing, and this is a sign that parts within the motor are severely worn.
Worn parts will struggle to produce enough torque and are more susceptible to breakage. Wearing is more likely to occur if there is contamination in the hydraulic fluid, causing friction when driven against components.
2. Whining or Knocking Sounds
As with most heavy machinery, hearing unusual noises is a sign that something is wrong.
Whining or whistling sounds are often a sign that the hydraulic motor is unable to produce enough torque for the load. Ease off immediately to prevent a complete breakdown and reduce loads until you can book a repair.
Grinding or knocking can indicate that components such as bearings or pistons are worn out or corroded. This can be caused by air in the hydraulic fluid. Bubbles occur when fluid is low or filters are clogged, or when the system overheats. They pop and cause cavitation or pitting, which then leads to contamination.
Sometimes, louder knocking sounds are a sign that components inside the motor are loose. Stop operations immediately and book a repair to prevent further damage.
3. Fluid Leak
Leaking hydraulic fluid from around the housing, fittings or shaft can reduce pressure in the hydraulic system, drawing in air and reducing the amount of pressure the machine can produce.
If fluid is leaking from a hydraulic motor, deteriorating seals are likely to be the main cause. This can also lead to fluid contamination within the system, leading to wearing and corrosion of internal parts.
4. Overheating
You might notice your hydraulic motor running hotter than previously, generating a lot of heat even when running for a few minutes. High heat will lead to quick degradation of seals and components, so overheating is cause for concern. Letting it continue will cause further problems such as pressure loss, wear and contamination. It can also damage connected systems, resulting in more costly repairs.
Regular maintenance should be sufficient to prevent overheating. Check that the system has enough hydraulic fluid and that it is clean and replaced regularly. Change filters with quality replacements. If the motor continues to overheat, a repair diagnostic will identify the problem and prevent further damage.
5. Jerking Movement
When hydraulic machinery stops moving smoothly, operations can be quickly disrupted as materials are dropped or damaged. Jerking, erratic performance is a sign of internal scoring, blocked valves or contaminated fluid, and usually gets worse as time passes.
The jerking may be due to a wobble in the rotary shaft, caused by scoring or corrosion. This could be an indicator of misalignment. Addressing these issues promptly, you will extend the life of your hydraulic motor and prevent the need for more costly repair work.
Reasons Your Hydraulic Motor May Fail
In a complex system like hydraulics, there is a lot that can go wrong. With so many different signs of damage, there are also various causes, some of which are discussed above. To summarise, here are a few reasons why hydraulic motors break down.
- Fluid contamination – whether dirt, water or air, anything other than hydraulic fluid in your system can abrade the internal components
- Corrosion or cavitation – pitting caused by water or condensation in pistons and cylinders can lead to further damage
- Seal failure – the plastic and rubber used for seals can degrade over time, or under high heat or chemical contact, leading to loss of fluid or lubrication
- Improper maintenance – failure to change fluid or clean filters regularly can cause damage that gradually gets worse
If you notice any of the above signs in your hydraulic machinery, it is time to contact a reputable hydraulic repair service. Repairing early is often more affordable than replacing parts, and can show you ways to improve maintenance protocols and operation to make components last longer.
