Diagnosing and Resolving Air Contamination in Skat-Trak 1700C Hydraulic Systems

[MikePhua]

Hydraulic systems are the lifeblood of many heavy machinery models, including the Skat-Trak 1700C—an articulated compact loader favored for its maneuverability and power. One common issue that can severely impact hydraulic performance is the presence of air within the hydraulic fluid. Air contamination causes spongy controls, erratic movements, and accelerated wear on components. Understanding how to identify, diagnose, and resolve air in the hydraulic system is essential for maintaining optimal operation and longevity of the Skat-Trak 1700C.
What Happens When Air Enters Hydraulic Systems?
Air inside the hydraulic fluid compresses under pressure, unlike liquid, leading to:

• Delayed or sluggish actuator response.
  
• Jerky or unpredictable movement of boom, bucket, or steering.
  
• Increased noise such as knocking or whining in the hydraulic pump.
  
• Potential cavitation damage.
  
• Reduced system efficiency and overheating.
  

Common Causes of Air in Skat-Trak 1700C Hydraulics

• Loose or damaged fittings and connections allowing air ingress.
  
• Low hydraulic fluid levels causing cavitation or vacuum.
  
• Leaking seals or hoses introducing air.
  
• Improper maintenance procedures, such as incomplete bleeding after repairs.
  
• Contaminated or degraded hydraulic fluid with entrapped air.
  
• Faulty hydraulic pump or accumulator malfunction.
  

Step-by-Step Troubleshooting and Resolution

1. Visual and Auditory Inspection
   • Listen for unusual noises from the hydraulic pump or valves.
     
   • Observe hydraulic cylinders and hoses for leaks or damage.
     
   • Check fluid reservoir level and condition.
     
2. Check and Tighten Connections
   • Inspect all hydraulic line fittings and tighten if loose.
     
   • Replace damaged hoses or fittings that allow air entry.
     
3. Fluid Level and Quality
   • Ensure hydraulic fluid is at the correct level.
     
   • Drain and replace fluid if it appears foamy or contaminated.
     
4. Bleeding the Hydraulic System
   • Follow manufacturer guidelines to bleed air from hydraulic cylinders, lines, and valves.
     
   • Operate all hydraulic functions slowly during bleeding to purge trapped air.
     
5. Inspect Seals and Components
   • Check seals on cylinders and pumps for wear or damage.
     
   • Replace faulty seals causing air intrusion.
     
6. Pump and Accumulator Evaluation
   • Test hydraulic pump performance; replace if cavitating or failing.
     
   • Inspect accumulator pre-charge pressure and condition.
     
7. System Testing
   • After repairs and bleeding, operate all hydraulic functions to confirm smooth, responsive controls.
     
   • Monitor for return of air symptoms.
     

Technical Terms Explained

• Cavitation: Formation and collapse of vapor bubbles in hydraulic fluid causing damage and noise.
  
• Accumulator: A pressurized device storing hydraulic fluid to smooth system pressure fluctuations.
  
• Bleeding: The process of removing trapped air from hydraulic lines and components.
  
• Seal: A component that prevents fluid leakage and air entry at joints and moving parts.
  
• Foamy Fluid: Hydraulic oil with bubbles or air pockets, reducing its effectiveness.
  

Additional Insights and Case Examples
A Skat-Trak 1700C owner experienced erratic steering and boom control. After thorough inspection, a cracked hose was found allowing air ingress. Replacing the hose and carefully bleeding the system restored normal operation. This case highlights the importance of regular hose inspections.
In another example, after hydraulic system servicing, incomplete bleeding left residual air in the fluid. The operator resolved the issue by following a detailed bleeding procedure, emphasizing that proper maintenance steps are as crucial as part replacement.
Historically, air contamination has plagued many hydraulic systems, but improved hose materials, sealing technologies, and maintenance protocols have significantly reduced occurrences. Operator training on system bleeding remains a critical factor in preventing air-related problems.
Maintenance Tips to Prevent Air in Hydraulics

• Regularly inspect and replace worn hoses and seals.
  
• Maintain proper fluid levels and use manufacturer-approved hydraulic oils.
  
• Perform careful system bleeding after any repairs or fluid changes.
  
• Avoid running hydraulic pumps dry or with low fluid.
  
• Train operators and technicians on recognizing early signs of air contamination.
  

Addressing air contamination promptly in the Skat-Trak 1700C hydraulic system preserves equipment responsiveness, reduces wear, and extends component life. With systematic troubleshooting and preventive care, operators can maintain smooth, efficient hydraulic performance essential for demanding jobsite tasks.