Troubleshooting Issues with Drum Brakes That Are Not Functioning Properly

Understanding Drum Brakes Troubleshooting When They're Not Working

Drum brakes are a common braking system found in many vehicles, particularly older models or those with rear drum brakes. While they are effective and reliable, there may come a time when you notice that your drum brakes are not working as intended. Understanding the common issues that can arise with drum brakes and how to troubleshoot them is essential for maintaining vehicle safety and performance.

How Drum Brakes Work

Before diving into troubleshooting, it’s important to understand how drum brakes function. A drum brake system consists of several key components the brake drum, brake shoes, wheel cylinder, and various springs and hardware. When the driver applies the brakes, hydraulic pressure is generated, pushing the brake shoes against the inner surface of the rotating drum. This friction slows the wheel's rotation and, consequently, the vehicle.

Common Reasons for Drum Brakes Not Working

1. Worn Brake Shoes Over time, the brake shoes can wear down due to continuous use. Worn shoes may not make sufficient contact with the drum, leading to decreased braking power. Regular inspections can help identify wear and tear before it becomes a serious issue.

2. Air in the Brake Lines If air has entered the hydraulic system, it can lead to a spongy brake pedal and ineffective braking. This situation can arise if the brake fluid is low, or there has been a leak in the brake lines. Bleeding the brake system can remove air and restore proper function.

3. Brake Fluid Leakage A leak in the hydraulic brake lines or around the wheel cylinder can significantly affect braking performance. Inspect the brake fluid level and look for signs of leaks under the vehicle. If you identify a leak, it’s critical to repair it immediately.

4. Rust and Corrosion Drum brakes, particularly in older vehicles or those exposed to harsh weather conditions, can suffer from rust and corrosion. This buildup can affect the movement of the brake shoes and wheel cylinder, leading to issues with braking performance. Regular cleaning and inspection can help mitigate this issue.

5. Improper Adjustment Drum brakes require regular adjustment to ensure that the brake shoes are positioned close enough to the drum for effective braking. If the brakes are not properly adjusted, they may not engage effectively. Consult your vehicle's service manual for proper adjustment procedures.

6. Faulty Wheel Cylinder The wheel cylinder plays a crucial role in pushing the brake shoes out against the drum. If the wheel cylinder is faulty or leaking, it can lead to brake failure. A visual inspection can help determine if the wheel cylinder needs to be replaced.

If you notice that your drum brakes are not working properly, follow these troubleshooting steps

1. Visual Inspection Begin with a visual inspection of the brake components. Look for signs of wear, rust, leaks, or any broken parts. Pay particular attention to the brake shoes and drum.

2. Check Brake Fluid Examine the brake fluid level in the master cylinder. If it is low, top it off with the appropriate type of brake fluid as specified in your vehicle manual. If you regularly find low levels, investigate for leaks.

3. Bleed the Brakes If you suspect air in the brake lines, bleed the brakes to remove air bubbles. This process involves having someone press the brake pedal while you open the bleeder valve on each wheel cylinder, working from the farthest brake from the master cylinder to the nearest.

4. Adjust Brake Shoes Check the adjustment of the brake shoes to ensure they are close enough to the drum. Adjust them as needed to maintain optimal performance.

5. Consult a Professional If you are unable to identify or fix the issue, it may be time to consult a professional mechanic. They possess the knowledge and tools necessary to diagnose and repair drum brake systems effectively.

Conclusion

Drum brakes are an efficient and reliable braking system, but issues can arise that may compromise their performance. By understanding the common problems and employing effective troubleshooting methods, you can maintain the integrity of your drum brakes. Always prioritize safety; if you’re unsure about the condition of your brakes or how to proceed with repairs, seek professional assistance to ensure your vehicle remains safe for the road. Regular maintenance and timely interventions can prevent minor issues from becoming significant safety hazards.