Hydraulic cylinder leak in a loader detected by sensors

Hydraulic cylinder leak detection with wireless sensors helped the maintenance team at Vale’s Sossego Mine find an evolving failure in a loader’s lift cylinders.

The sensors showed a temperature difference above 3 °C between the cylinder pair and a peak of 81 °C on the left side. The team replaced the cylinder before the fault cut the operation’s efficiency by about 40%.

In this case study, you will see how lift cylinder failures develop, how temperature data revealed the leak and how to monitor hydraulic cylinders on mobile equipment.

Why loader availability matters in mining

The loader is a common piece of equipment in mining operations and infrastructure works. It loads and moves material along the production chain, so an unscheduled stop can affect the whole operation.

Maintenance is the main factor in keeping loaders running safely, because it prevents accidents caused by common mechanical failures. Like other off-highway vehicles, loaders work under heavy loads, dust and long shifts.

With this in mind, the maintenance team at Vale’s Sossego Mine invested in remote monitoring of its loaders. The goals were to reduce unscheduled downtime, avoid drops in productivity and make the operation safer.

How hydraulic lift cylinder failures develop

Hydraulic cylinders move the shovel that carries material from one point to another. Sealing problems are among the most common defects in their operation. The most frequent causes of seal damage are:

• Excessive friction between moving parts, which wears the seals over time.
• Contaminated hydraulic fluid, which carries particles that scratch seals and surfaces.
• Damage to the rod, which tears the seal at each stroke.

Seal damage leads to leaks that affect the hydraulic system. The cylinder loses internal pressure and, as a result, the temperature difference between the two cylinders of the pair increases. Comparing them becomes an early sign of failure.

How temperature monitoring detected the leak

By analyzing temperature levels, the team at the Sossego Mine detected an abnormal rise between the lift cylinders of a loader. The behavior pointed to an internal or external leak in development.

When the team compared the two cylinders of the pair, the difference in temperature rise was greater than 3 °C, further evidence of an evolving fault.

On the Dynamox Platform, the global temperature graph of the left-side cylinder showed that its temperature had practically doubled, reaching a peak of 81 °C.

Based on this data, the team requested the replacement of the left-side cylinder. Soon after the repair, the temperature levels dropped and returned to normal operating standards.

Results for the Sossego Mine team

Unscheduled shutdowns bring production losses, higher repair costs and more risk for operators. In loader operations, most of these losses come from low equipment performance.

According to the Sossego Mine maintenance team, a developing lift cylinder anomaly reduces the operation’s efficiency by about 40%, besides the risk of damaging the cylinder pair.

Monitoring also supports operator safety in industrial areas, in line with NR12, the Brazilian regulatory standard for machinery safety.

For Oziel Soares da Silva, Operational Predictive Analyst at the Sossego Mine: “The solution brings, first of all, a gain in safety. The predictive technician does not need to be exposed to risks such as being run over, crushed, weather conditions and environments with bad weather. The physical integrity of our collaborator is our greatest gain. Then, we start to have failure predictability with accuracy, providing a schedule with guaranteed operational reliability of the machine in a shorter maintenance time.”

How to monitor hydraulic cylinders on mobile equipment

The Sossego case shows a few practices that apply to loaders and other mobile equipment:

1. Compare the cylinders of the same pair. The difference between them reveals a leak earlier than the absolute value of each one.
2. Set alarms by temperature difference. An alert when the gap between cylinders passes a defined limit catches the fault in its early stage.
3. Follow the temperature trend over time. A steady rise shows that the fault is progressing and helps define when to intervene.
4. Combine sensor data with visual inspection. Signs of external leakage on the rod or fittings confirm what the data shows.
5. Keep the hydraulic fluid clean. Contamination is one of the main causes of seal wear.

In this case, DynaLogger HF wireless sensors monitored the vibration and temperature of the asset, and the data reached the Dynamox Platform. To learn more about the technique, read the guide on temperature monitoring in industrial maintenance.

You can also see other mining cases with the same team and assets:

• Predictive maintenance of conveyor belts at the Sossego Plant
• Remote monitoring of off-highway vehicles at Vale Carajás
• Hydraulic system monitoring with temperature sensors

➡️ See more success cases from Dynamox.

Want to monitor the mobile equipment in your operation? Talk to Dynamox specialists.

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