Case 680B Backhoe Loader Brake Parts: Essential Components and Maintenance

[MikePhua]

Introduction to Case 680B Brake System
The Case 680B backhoe loader is a classic and widely used machine in construction and agriculture, renowned for its durability and versatility. A critical safety and operational feature of the 680B is its brake system. Proper maintenance and timely replacement of brake parts ensure safe handling, precise control, and longevity of the equipment.
Understanding the brake components, their functions, and maintenance requirements is vital for operators and mechanics working with the Case 680B.
Key Brake Components of the Case 680B

• Brake Shoes: Curved friction components that press against the brake drum to slow or stop the machine.
  
• Brake Drums: Rotating cylinders attached to the wheel hubs that the brake shoes clamp onto.
  
• Brake Bands: Metal bands that wrap around drums or components, providing additional braking force.
  
• Hydraulic Cylinders: Convert hydraulic pressure into mechanical force to engage the brakes.
  
• Master Cylinder: Generates hydraulic pressure when the brake pedal is pressed.
  
• Brake Lines and Hoses: Carry hydraulic fluid from the master cylinder to the brake cylinders.
  
• Adjusters: Mechanical devices to maintain correct clearance between shoes and drums.
  

Common Brake Maintenance and Repair Tasks

• Inspection of Brake Shoes and Drums
  • Check for wear thickness and replace shoes if below specification.
    
  • Inspect drums for scoring, cracks, or warping.
    
• Hydraulic System Check
  • Look for leaks in brake lines and cylinders.
    
  • Bleed the system to remove air bubbles, ensuring firm brake pedal feel.
    
• Adjust Brake Clearance
  • Use adjusters to maintain proper gap for effective braking.
    
• Replace Worn or Damaged Parts
  • Replace brake shoes, bands, or cylinders as necessary.
    
  • Use OEM parts or high-quality aftermarket equivalents for reliability.
    

Troubleshooting Common Brake Issues

• Soft or Spongy Brake Pedal
  • Often caused by air in hydraulic lines or low fluid levels.
    
• Brake Dragging
  • Could be due to misadjusted shoes or seized hydraulic cylinders.
    
• Uneven Braking
  • May result from worn shoes or leaking cylinders on one side.
    
• Brake Noise
  • Caused by worn linings, contamination, or glazed shoes.
    

Tips for Effective Brake Maintenance

• Regularly check fluid levels and top up with recommended hydraulic oil.
  
• Schedule periodic inspections of brake components.
  
• Keep brake assemblies clean from dirt and debris.
  
• Replace parts in matched sets to ensure balanced braking.
  
• Train operators to notice early signs of brake problems.
  

Terminology Explained

• Brake Shoes: Friction pads that press against drums to create stopping force.
  
• Brake Drum: Rotating part of the wheel assembly that shoes clamp onto.
  
• Hydraulic Cylinder: Converts hydraulic pressure into movement to engage brakes.
  
• Bleeding: The process of removing trapped air from hydraulic brake lines.
  
• Brake Band: A flexible band that tightens around a drum or component to assist braking.
  

Case Story: Restoring Brake Performance on a Case 680B
A small excavation business in Ohio noticed their 680B backhoe loader had decreased braking efficiency. After inspection, they found worn brake shoes and minor leaks in the hydraulic brake cylinders. By replacing the shoes, repairing seals in the cylinders, and thoroughly bleeding the brake system, they restored the braking performance to factory standards. The timely maintenance avoided potential safety hazards and costly repairs.
Conclusion
Maintaining the brake system on the Case 680B backhoe loader is essential for safe and efficient machine operation. Familiarity with key brake parts, recognizing symptoms of wear or failure, and performing regular maintenance will help extend equipment life and protect operators. Investing in quality brake components and diligent servicing ensures the Case 680B remains a dependable workhorse on any job site.