Excavator Losing Hydraulic Power? Causes & Fixes Explained

Excavator Losing Hydraulic Power? Causes & Fixes Explained

Excavators rely on a high-pressure hydraulic system to operate their boom, arm, bucket, and other attachments. If your excavator starts losing hydraulic power, it can slow down operations, reduce digging force, and even cause complete failure.

In this guide, we’ll explore the most common causes of hydraulic power loss in excavators, how to diagnose the problem, and step-by-step solutions to fix it.

1. What Are the Common Causes of Hydraulic Power Loss in an Excavator?

A loss of hydraulic power in an excavator can be caused by various factors, including low hydraulic pressure, fluid contamination, pump failure, or faulty control valves. Let’s break these down:

a) Low Hydraulic Fluid Levels or Leaks

Hydraulic systems rely on pressurized fluid to generate power. If the fluid level is low due to leaks or improper maintenance, power loss occurs.

Possible Causes:

  • Hydraulic fluid leaks from hoses, seals, or cylinders
  • Low fluid levels due to evaporation or poor maintenance
  • Loose or damaged hydraulic connections

Solutions:

✅ Inspect all hydraulic hoses, cylinders, and connections for visible leaks.
✅ Tighten loose fittings and replace damaged seals.
✅ Refill hydraulic fluid to the recommended level.
✅ Use manufacturer-approved hydraulic oil to maintain system efficiency.

For step-by-step hydraulic system maintenance, refer to excavator service manuals.

b) Clogged Hydraulic Filters

Hydraulic filters prevent dirt and debris from contaminating the system. If they become clogged, fluid flow is restricted, leading to poor hydraulic performance.

Possible Causes:

  • Dirty or clogged hydraulic filters reducing fluid flow
  • Contaminated oil from dirt, metal particles, or water
  • Poor maintenance practices

Solutions:

✅ Replace clogged hydraulic filters regularly to maintain fluid pressure.
✅ Drain and replace contaminated oil—use high-quality hydraulic fluid.
✅ Perform regular oil sampling to check for contaminants.

For detailed hydraulic filter replacement steps, check the Case Construction Equipment manuals.

c) Worn-Out Hydraulic Pump

The hydraulic pump is the heart of the system, generating the pressure needed to move the excavator’s components. If it wears out, power loss will occur.

Possible Causes:

  • Hydraulic pump wear and tear over time
  • Air or cavitation in the pump causing inefficiencies
  • Low oil viscosity affecting pump performance

Solutions:

✅ Check hydraulic pressure using a pressure gauge—if it’s too low, the pump may be failing.
✅ Bleed air from the hydraulic system to eliminate cavitation.
✅ Replace the hydraulic pump if it’s worn beyond repair.

For hydraulic pump troubleshooting and replacement, refer to the John Deere machinery manuals.

d) Faulty Control Valves

Control valves regulate the flow of hydraulic fluid. If they fail, the excavator may lose digging force or become slow to respond.

Possible Causes:

  • Valve blockages or contamination
  • Damaged or leaking seals in the control valve
  • Malfunctioning pilot control system

Solutions:

✅ Inspect and clean hydraulic control valves to remove debris.
✅ Replace worn-out seals to prevent fluid leakage.
✅ Test pilot controls—if they’re unresponsive, they may need repair.

For control valve repair steps, check the Volvo Equipment manuals.

e) Air in the Hydraulic System

Air bubbles in the hydraulic fluid reduce pressure and efficiency, leading to weak power output.

Possible Causes:

  • Improper hydraulic fluid refilling causing air pockets
  • Leaking suction hoses allowing air to enter
  • Faulty hydraulic pump seals

Solutions:

✅ Bleed air from the hydraulic system by following the manufacturer’s procedure.
✅ Check suction hoses for leaks and replace if necessary.
✅ Inspect and replace worn pump seals to prevent air intake.

For air bleeding procedures, refer to the Case IH Equipment manuals.

f) Overheating Hydraulic System

Excessive heat reduces oil viscosity and can cause loss of hydraulic efficiency.

Possible Causes:

  • Dirty or clogged hydraulic oil cooler
  • Worn-out hydraulic fluid reducing cooling properties
  • High ambient temperatures affecting system performance

Solutions:

✅ Clean the hydraulic oil cooler to improve cooling efficiency.
✅ Use high-quality hydraulic fluid with the correct viscosity.
✅ Monitor oil temperature and avoid overheating conditions.

For hydraulic system cooling tips, check the bulldozer repair manuals.

2. How to Prevent Hydraulic Power Loss in an Excavator?

Regular maintenance is essential to keeping your excavator’s hydraulic system working properly. Follow these preventive measures:

✔ Check and replace hydraulic filters every 250-500 hours.
✔ Monitor hydraulic fluid levels daily and refill if needed.
✔ Inspect hoses and seals for leaks and replace them as necessary.
✔ Bleed air from the system whenever hydraulic fluid is changed.
✔ Keep the hydraulic cooler clean to prevent overheating.

For a complete maintenance schedule, refer to PdfManualsShop.com.

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If you’re experiencing hydraulic power loss in your excavator, a service and repair manual can help you diagnose and fix the issue efficiently.

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