Your Troubleshooting Guide for Overheating Hydraulic Power Units

A high temperature in the hydropower device (HPU) isn't an inconvenience; it's a direct danger to the efficiency of your system, longevity, component lifespan, and overall security. When the hydraulic fluid temperature rises above its optimum range (typically $180^\circ\text$ or $82^\circ\text$ is considered too high), it rapidly degrades seals, accelerates fluid breakdown, and increases wear on pumps and motors.

In the event that your HPU is operating hot, don't sit around waiting to see if it's a problem. Utilize this guide to swiftly identify and repair the most frequently cited causes for excessive heat!

Phase 1: Review the basics (Low-Hanging Fruit)

Begin by tackling the simplest and most frequent problems that can be fixed without requiring a complex diagnosis.

Basic Troubleshooting of HPU Overheating

• Low Level of Fluid

  • The reason: Insufficient oil in the reservoir can limit heat dissipation and may also introduce air (aeration).

  • Quick Solution: Top off the fluid at the right level, making sure the type of fluid and viscosity are in line with the specifications of the system.

• Drip Cooler Clogged/Clogged

  • The reason: Air or water heat exchangers (coolers) that are blocked by debris, dirt, or sludge are unable to transfer heat efficiently.

  • Quick fix: Clean the fins on the outside of air coolers by using compressed water or air. If you are using a water-cooled cooling system, look for obstructions on the water lines or the heat exchanger's core.

• Wrong Fluid Viscosity

  • The reason: Fluid that is too thick (high viscosity) results in excessive internal friction. Fluid that is small (low viscosity) creates internal leakage and inadequate lubrication. Both of these can cause the creation of heat.

  • Quick Solution: Verify the quality of the fluid in accordance with the manufacturer's guidelines and replace the fluid in case of an error. Always be aware of the operating temperature.

• Blocks Airflow

  • The reason: Insufficient ventilation around the HPU, particularly around the reservoir and motor.

  • Quick Solution: Ensure the power unit is situated in an air-conditioned space and ensure that all cooling and vent fans are clear and free of obstructions to airflow.

Phase 2: Fluid Contamination & System Inefficiencies

If the basic checks out, it is most likely that the issue is internal and is usually related to the condition of fluids or mechanical wear.

Aeration or Contaminated Fluid

• Contamination of Water, dirt, or any other particles within the fluid increases friction and causes parts (especially valves and pumps) to fail, resulting in internal leakage as well as heat.

  • The Solution: Change the filter and fluid immediately. Invest in regular analysis of the fluid and filtration that is high-quality to avoid recurrence.

• Aeration (Air in the System): Air bubbles that get into the oil (often via leaky suction lines or return line) create immense heat when they are compressed and then released.

  • The Solution: Inspect the suction line, reservoir seals, and the seal on the pump shaft to find leaks. Replace or tighten the fittings or seals to prevent air ingress.

Internal Leakage and Pressure Problems

• A damaged motor or pump: As pumps or motors age, their internal clearances increase and allow pressurized fluid to escape from the high-pressure side to the side of low pressure. This energy loss is converted to heat directly.

  • The Solution: Test the component's effectiveness. A worn pump or motor needs to be repaired or replaced to stop the heating process.

• Dumping of the relief valve, an incorrectly set or worn-out main relief valve, can constantly redirect fluid back to the reservoir under high pressure. This is a waste of energy that can be transformed into heat.

  • The Solution: Check and reset the pressure relief valve to the proper specifications. In the event that your valve appears to be leaking when it shouldn't, it is likely to require removal and cleaning or replacement.

• High-pressure Pressure Drop Limitations in lines, hoses, or components that are not sized properly cause the pump to produce greater pressure in order to keep the flow going, which leads to the production of heat.

  • The Solution: Inspect hoses for collapsing, kinks, or wear that restricts flow. Ensure that all components, including filters as well as plumbing, are sized correctly to the flow rate of the system.

3. Phase: Advanced Diagnostics

If the problem continues, the problem persists, you must determine and identify the heat source.

1. Utilize an Infrared Thermometer to scan every major component (pump motor, pump heater, reservoir relief valve, along main lines). The presence of a hot or unusually hot part can be traced directly to the source of the problem or drop in pressure.

2. Conduct an unloaded test: Run the HPU without the actuators connected (or in an unloaded, neutral state). If the temperature is still rising, it is probably inside the pump, or relief valve, or the bypass valve. If the temperature is steady, it is most likely to be due to the excessive outside load or an app-side issue.

3. Test of Pressure Gauge: Use a gauge to determine the pressure level on your relief valve, and be sure that it's not working at its maximum