SkyJack SJ7027 Brake Issues

[MikePhua]

Equipment Background
The SkyJack SJ7027 is a telescopic boom lift produced by SkyJack, a Canadian company founded in 1985. SkyJack has a global reputation for manufacturing reliable aerial work platforms with a focus on cost-effective maintenance and user-friendly operation. The SJ7027 is part of the 7000 series, designed for construction, industrial, and maintenance applications, providing a working height of 25 meters (82 feet) and a platform capacity of 340 kg (750 lbs). This model is widely used due to its combination of reach, stability, and transportability.
Brake System Overview
The SJ7027 employs a combination of hydraulic and mechanical braking systems. Its primary braking function is hydraulic, controlled via the main lift circuit, with a mechanical fail-safe that engages when hydraulic pressure drops. The brakes operate on all four wheels and include an integrated parking brake that holds the platform in place when idle. Typical components include:

• Hydraulic calipers and discs
  
• Mechanical parking lock
  
• Brake fluid reservoir and lines
  
• Emergency stop interlocks
  

Common Symptoms of Brake Problems
Operators have reported several recurring brake issues on the SJ7027:

• Reduced braking efficiency, causing the lift to drift on inclines
  
• Spongy or unresponsive brake pedal or control lever
  
• Sudden engagement of the mechanical parking brake
  
• Warning lights triggered due to low hydraulic pressure
  

These symptoms may arise due to wear, contamination, or hydraulic system leaks.
Troubleshooting and Solutions
To address SJ7027 brake problems, follow a systematic approach:

• Check hydraulic fluid levels: Low or contaminated hydraulic oil can compromise brake function. Use only manufacturer-recommended hydraulic fluid, and inspect for debris or moisture.
  
• Inspect brake pads and discs: Worn pads reduce stopping power; replace if thickness is below minimum specification. Typical pad wear limit is 3 mm.
  
• Examine hydraulic lines and fittings: Look for leaks or loose connections; even minor hydraulic leaks can reduce brake responsiveness.
  
• Test parking brake mechanism: Ensure the mechanical lock fully disengages. Corrosion or misalignment can prevent proper release.
  
• Check sensors and interlocks: Faulty pressure switches or control sensors can falsely signal a brake issue, triggering warning lights.
  
• Bleed hydraulic system: Air trapped in lines can cause sponginess. Use proper bleeding procedures to eliminate air pockets.
  

Preventive Maintenance Recommendations
Preventive care is key for reliable brake performance:

• Monthly visual inspections of brake components, hoses, and connections
  
• Quarterly hydraulic fluid analysis to check for contamination or degradation
  
• Annual full brake system inspection by certified technicians
  
• Keep the lift clean: Dirt and debris can accelerate wear on brake components and compromise sensors
  

Safety Considerations
Brake issues on an aerial lift pose significant risks. Operators should always:

• Engage the parking brake before leaving the platform
  
• Avoid operating on steep inclines if brake performance is uncertain
  
• Follow lockout/tagout procedures during maintenance
  
• Wear PPE, including harness and fall protection, while troubleshooting
  

Operational Tips

• Use slow, controlled movements on slopes to reduce stress on brakes
  
• Avoid sudden stops when carrying maximum load
  
• Regularly test brake response at low elevation to ensure proper engagement before full operation
  

Conclusion
The SkyJack SJ7027’s brake system, while robust, is susceptible to wear and hydraulic-related issues. Systematic inspection, proper maintenance, and adherence to safety protocols are essential for consistent performance. Operators who follow these guidelines can maintain reliable braking, reduce downtime, and ensure the safe operation of this high-reach platform.