Hydraulic systems are subjected to continuous, heavy-duty work conditions that place major stresses on the pump and associated components. As such, hydraulic equipment needs to be frequently checked to ensure everything is in good working order. This is especially true of the system’s pump, which is filled with hundreds of small components working in unison to drive power. Failure anywhere in the pump or system can quickly cause catastrophic damage to the equipment.

This is why it’s important for operators to know what signs may indicate potential problems. Here are four signs that should immediately put your work crews on high alert.

1) There’s a Rattling or Growling Sound Coming from the Pump

Unusual noise is typically the first sign that there’s something going wrong with the pump. As for what’s unusual, that depends on the pump, as every pump makes some sound during operation. Operators that have experience with the system should be able to pick out any strange noises. In most cases, these noises will have a banging, rattling or growling quality to them.

If such sounds are present, the root cause is almost always aeration. If air becomes entrained in the hydraulic fluid, it can cause a variety of issues, including cavitation.

During cavitation, air bubbles form due to a vacuum present somewhere in the system. Eventually, these air bubbles implode, and the resulting force is enough to strip surface material from nearby components. Severe pitting and early component failure may result from this process.

Additional causes of noise include bearing wear and internal damage to components.

2) The System’s Hydraulic Actuators are Responding Slower Than Normal

The cylinder’s actuators receive fluid power from the pump and convert it into linear force. As the cylinder heads retract, hydraulic fluid is returned to the reservoir and the actuator retracts. This push and pull process operates on a consistent rhythm that ensures maximum operation efficiency. It’s like the system’s heartbeat.

If actuator cycling slows, then this is a strong sign that the system is losing flow or pressure somewhere. This could be due to leaks, either internal or external. External leaks are normally easy to spot and tend to occur in obvious areas, such as around fittings or hose connectors. Internal leaks are tougher to diagnose, but usually present around valves, seals or inside cylinders. Monitoring fluid levels for any internal loss is the best way to spot this problem.

3) The System Isn’t Outputting as Much Force as Normal

If hydraulic cylinders experience a dip in force output, it will compromise project safety and efficiency. And if this does occur, it’s almost always a sign that cylinder repairs are needed. The problem may exist inside the cylinder itself, as the piston may be corroded or otherwise damaged. Other common culprits are seals, especially piston seals, as they are responsible for maintaining internal fluid pressures and preventing fluids from bypassing the piston. If these seals are compromised, it can cause the piston to have positioning or motion issues, both of which may manifest as loss of force.

4) Temperatures Inside the System Are Elevated or Swinging Up and Down

Hydraulic fluid temperature must be maintained within a relatively tight range to ensure optimal viscosity and, by extension, optimal flow rates. If the fluid overheats, it may become too thin and will affect cylinder and seal performance.

Overheating or unusual temperature swings may be caused by one or several underlying factors. Some of these are operational in nature. For example, placing too much load on the pump can cause temperature spikes.

In most instances, though, overheating or temperature fluctuations are a sign of component failure inside the pump. The fix could be relatively simple, like cleaning any clogged filters. It’s common for pumps located under the reservoir to become clogged in this way, as they can be difficult to access (and therefore easy to neglect). Regular inspection and cleaning is highly recommended, and operators may elect for alternative means of filtration, such as using a kidney loop.

Aeration may also cause overheating, as air bubbles release thermal energy into nearby fluid when they implode. A low fluid level may also be the problem, as hydraulic fluid absorbs some of the heat resulting from the pump’s operation. If there isn’t enough fluid, more of this heat will be passed to adjacent components.

And finally, a damaged or malfunctioning heat exchanger may be the reason behind temperature issues. The heat exchanger is responsible for extracting heat out of the fluid as it circulates, either through a liquid or air medium. If it isn’t properly fed with coolant or if the exchanger is affected by corrosion, for example, it will not do its job efficiently enough.

A Basic Maintenance Routine Will Often Catch Minor Issues Before They Become Costly Problems

Nothing beats a hydraulic system in terms of power delivery, but operators must keep an eye on any potential failure points to ensure ongoing efficiency and reliability. Keeping to a consistent maintenance routine is highly recommended, and such a routine should include the following:

• Checking oil and fluid levels/quality – The system’s oil and hydraulic fluid levels should be checked according to manufacturer specifications, or at least prior to every job. Fluid levels and quality are important, so be sure to look for any signs of contamination.
• Cleaning or replacing filters regularly – If the system’s filters, including the breather, become clogged, operating temperatures will climb, flow may decline, and contaminants may damage interior components. Check the filters prior to every job and either clean or replace any that are clogged.
• Inspecting the piston rod – As the system’s force delivery mechanism, the piston rod should be occasionally checked for signs of damage, such as pitting. Damage to the rod may encourage condensation to build up inside the cylinder, which can cascade into major cylinder issues.
• Replacing any worn seals – If the seals go, fluid bypasses are likely to occur, and leaks may emerge. Excess fluid pressures or temperatures can cause seal damage, so if the system has had recent issues with either, it would be a good idea to check the seals’ condition inside the cylinder and pump.
• Checking the lines, pipes, and connections – The lines, pipes and connections are high-probability failure points, where contamination and leaks are highly likely to occur. It’s always a good idea to check the state of each prior to operation, including the length and number of fittings on each line. Lines that are too long or feature too many fittings may have flow issues.

In addition to the above, it’s a good idea to occasionally take the system’s temperature and listen to the sounds it makes. These are early clues that something is going wrong in the system. If responded to, expensive repairs may be avoided.

Hydraulic Tools Take a Beating, So Operators Should Be Maintenance-Minded

Heavy-duty, high-cycle operation is the rule for hydraulic power systems, and that intensity will stress equipment. Fortunately, hydraulic systems usually show signs that failure is imminent – early enough for maintenance to be administered.

If your team knows what to look for – and listen for – those issues can be spotted right away. And if your team has a trusted Houston hydraulic expert on call, they can be diagnosed and resolved before more expensive, and catastrophic issues emerge.