Brake Adjustment for Caterpillar 977L: A Comprehensive Guide

[MikePhua]

Introduction
The Caterpillar 977L, a well-regarded track loader, is used in a variety of heavy-duty tasks, including excavation, grading, and material handling. Like any heavy equipment, maintaining the brakes is essential to ensure safety and optimal performance. This article provides a guide to adjusting the brakes on the Caterpillar 977L to keep it functioning smoothly and efficiently.
Why Brake Adjustment is Necessary
Proper brake adjustment is crucial for maintaining the safety and effectiveness of the 977L loader. Over time, as brake pads wear down and components shift, the braking power can decrease. Adjusting the brakes ensures that the machine can stop effectively under various load conditions, preventing potential accidents and reducing wear on the braking system.
Signs That Brake Adjustment is Needed

• Increased Stopping Distance: If the 977L takes longer than usual to stop or feels unresponsive, the brakes may need to be adjusted.
  
• Uneven Brake Action: If one track slows down faster than the other, or there’s a noticeable difference in braking force, it’s time to check and adjust the brake system.
  
• Brake Pedal Feel: If the brake pedal feels soft or unusually stiff, or if it has too much play, adjustment might be necessary.
  
• Unusual Noises: Grinding, squealing, or other unusual sounds from the brake area often indicate worn-out components or improper adjustments.
  

Tools Required for Brake Adjustment
Before performing any brake adjustments, ensure you have the following tools:

1. Wrenches and sockets
   
2. Torque wrench
   
3. Hydraulic jack or lift
   
4. Brake adjusting tool (if applicable)
   
5. Safety gloves and eye protection
   
6. Brake fluid (if necessary)
   
7. Jack stands for added safety
   

Steps for Adjusting Brakes on the Caterpillar 977L

1. Ensure Safety First
   • Always park the 977L on a flat surface, engage the parking brake, and place wheel chocks around the tracks to prevent the machine from moving.
     
   • Wear appropriate safety gear, including gloves and eye protection.
     
2. Lift the Machine
   • Use a hydraulic jack or lift to raise the front or rear of the machine, depending on which set of brakes needs adjustment. Ensure the machine is securely supported with jack stands before beginning any work.
     
3. Locate the Brake Adjuster
   • The brake adjuster is typically located near the brake drum. You may need to remove a protective cover or access panel to reach the adjuster.
     
4. Check Brake Wear
   • Inspect the brake pads or shoes for signs of wear. If the pads are excessively worn, they may need to be replaced before adjusting. Look for any oil or grease contamination that could affect braking performance.
     
5. Adjust the Brake
   • Using a brake adjusting tool, rotate the adjuster in small increments, ensuring the brake shoes are correctly aligned with the brake drum.
     
   • Adjust each brake on both sides to maintain even pressure and ensure both tracks respond equally when the brake is engaged.
     
6. Check Brake Pedal Feel
   • After adjusting, check the brake pedal. It should feel firm but not too stiff. If the pedal still feels soft, you may need to adjust further or check for leaks in the brake fluid system.
     
7. Test the Brakes
   • Lower the machine back to the ground and test the brakes by applying pressure and checking for proper response. Take the 977L for a short drive to verify that the brakes engage and disengage smoothly and that the machine stops quickly when needed.
     
8. Repeat if Necessary
   • If the brakes do not respond as expected, repeat the adjustment process. Ensure both tracks are braking evenly and there’s no excessive play in the brake system.
     

Common Brake Issues and How to Address Them

1. Brake Drag
   • Brake drag occurs when the brake shoes are adjusted too tightly, causing them to make constant contact with the drum. This leads to overheating and premature wear. Adjust the brake shoes so that there’s a small gap between the shoes and the drum when the brake is not applied.
     
2. Uneven Braking
   • If one track is braking more than the other, check the adjustment on both sides. Uneven wear on the brake pads could also be a sign of alignment issues, which should be addressed by checking the brake components and ensuring they are properly centered.
     
3. Soft Brake Pedal
   • A soft brake pedal can indicate air in the brake lines or low brake fluid. Bleed the brake system to remove any air, and top off the fluid if necessary.
     
4. Brake Noise
   • Unusual brake noises can often be attributed to worn-out brake pads, debris caught in the brake system, or insufficient lubrication. Inspect the brake pads and clean the components before adjusting.
     

Conclusion
Regular brake adjustments are crucial for maintaining the performance and safety of the Caterpillar 977L loader. By following the steps outlined above, operators can ensure that their brakes function properly, reducing the risk of accidents and minimizing downtime. Always perform routine inspections and adjustments to avoid premature wear and ensure optimal braking performance.