Troubleshooting Auxiliary Hydraulics Issues on the CAT 267 Skid Steer Loader

[MikePhua]

Overview of Auxiliary Hydraulics on the CAT 267
Auxiliary hydraulics in skid steer loaders like the CAT 267 enable operators to power various attachments such as hydraulic breakers, augers, and trenchers. These systems are essential for expanding the versatility and efficiency of the machine on job sites. When the auxiliary hydraulics fail to operate correctly, it can halt work progress and require systematic troubleshooting to identify the root cause.

Common Symptoms of Auxiliary Hydraulic Failures
Operators may notice several signs indicating auxiliary hydraulic issues:

• No hydraulic flow or pressure to the attachment.
  
• The attachment functions intermittently or weakly.
  
• Hydraulic fluid leaks near the auxiliary hydraulic lines or connections.
  
• Abnormal noises or erratic operation of the hydraulic system.
  

Primary Components Involved in Auxiliary Hydraulic Operation

• Hydraulic Pump: Supplies pressurized fluid to the auxiliary circuit.
  
• Control Valve: Regulates hydraulic fluid flow to attachments based on operator inputs.
  
• Relief Valve: Prevents overpressure by diverting excess fluid.
  
• Hydraulic Lines and Hoses: Transfer fluid between the pump, valves, and attachments.
  
• Couplers and Connectors: Interface points for attachment hydraulic hoses.
  
• Electrical Controls and Switches: Engage or disengage auxiliary hydraulics via joystick or control panel.
  

Step-by-Step Troubleshooting Approach

1. Visual Inspection
   • Check for obvious hydraulic fluid leaks around hoses, connectors, and valves.
     
   • Inspect hydraulic lines for cracks, damage, or loose fittings.
     
   • Ensure that the auxiliary hydraulic couplers are clean and properly connected.
     
2. Hydraulic Fluid Check
   • Verify fluid levels in the hydraulic reservoir are adequate.
     
   • Examine fluid condition; contaminated or degraded fluid can impair function.
     
3. Control Engagement Verification
   • Confirm that the auxiliary hydraulic switch or joystick control is activated.
     
   • Inspect electrical connections and switches for corrosion or damage.
     
4. Pressure Testing
   • Use a pressure gauge to measure hydraulic pressure at the auxiliary outlet.
     
   • Compare readings against manufacturer specifications.
     
5. Valve and Pump Examination
   • Inspect the control valve for internal faults or blockages.
     
   • Check the hydraulic pump operation; a worn or failing pump can reduce flow.
     
6. Relief Valve Setting
   • Verify that the relief valve is set correctly and not stuck open, which would reduce system pressure.
     

Terminology Explanation

• Auxiliary Hydraulics: Hydraulic circuits dedicated to powering attachments beyond the loader’s main functions.
  
• Control Valve: Device that directs fluid flow according to operator commands.
  
• Relief Valve: Safety valve to prevent excessive pressure build-up.
  
• Hydraulic Coupler: Quick-connect fitting allowing easy attachment connection.
  
• Pressure Gauge: Instrument measuring hydraulic pressure to aid diagnostics.
  

Supplemental Insights and Case Examples

• In one documented case, a CAT 267’s auxiliary hydraulics stopped working due to a simple electrical issue where the joystick switch wiring had become disconnected after rough handling, highlighting the importance of electrical system checks.
  
• Another scenario involved a clogged control valve spool preventing fluid from reaching the attachment. Cleaning or replacing the valve restored full function.
  
• Hydraulic pump wear is a common culprit in machines with high operating hours. Pump replacement or rebuilds, although costly, often revive auxiliary power and improve overall machine performance.
  

Maintenance Tips to Prevent Auxiliary Hydraulic Failures

• Regularly inspect hydraulic lines and couplers for wear or damage.
  
• Maintain proper hydraulic fluid levels and change fluid and filters according to manufacturer schedules.
  
• Avoid forcing attachments beyond their design capacity to reduce strain on hydraulic components.
  
• Protect electrical connections from moisture and mechanical damage.
  

Summary of Key Troubleshooting Steps

• Check for leaks, damage, and fluid level/condition.
  
• Confirm proper control activation and inspect electrical components.
  
• Measure hydraulic pressure to identify flow issues.
  
• Examine valves and pumps for mechanical faults.
  
• Adjust or repair relief valve settings if necessary.
  

Conclusion
Auxiliary hydraulic failures on the CAT 267 skid steer loader can stem from a variety of sources including mechanical wear, electrical faults, and maintenance neglect. A systematic approach combining visual inspection, hydraulic testing, and electrical diagnostics typically leads to a solution. By understanding key components and their roles, operators and technicians can minimize downtime, avoid costly repairs, and maintain optimal machine performance. Awareness of common causes and preventive maintenance will further extend the life and reliability of the auxiliary hydraulic system, ensuring that attachments function efficiently to meet diverse job site demands.