Troubleshooting Issues with Rear Drum Brakes Not Functioning Properly

Understanding Rear Drum Brakes Troubleshooting When They Stop Working

Brakes are one of the most vital components of any vehicle, responsible for ensuring safety on the road. Among the various types of braking systems, rear drum brakes are a common choice, especially for older vehicles and certain models of trucks and SUVs. However, like any mechanical part, they can encounter issues, leading to ineffective braking. This article will delve into the causes of malfunctioning rear drum brakes and how you can troubleshoot these issues.

How Rear Drum Brakes Work

Before addressing the problems, it’s essential to understand how rear drum brakes operate. The system consists of a drum, two brake shoes, a wheel cylinder, and various springs and hardware. When you press the brake pedal, hydraulic fluid is pumped into the wheel cylinder, causing the brake shoes to expand and press against the inner surface of the drum. The friction generated slows down the wheel and brings the vehicle to a stop.

Common Issues Leading to Malfunction

1. Worn Brake Shoes Over time, brake shoes can wear down, reducing their effectiveness. If you notice a decrease in braking performance, this could be a primary cause. It’s advisable to check the thickness of the brake shoes regularly.

2. Contaminated Shoes and Drum Oil, grease, or brake fluid leaks can contaminate the brake shoes and drum, leading to reduced friction and ineffective braking. If you smell burning or see a greasy residue on the brake components, it's crucial to address it promptly.

3. Failed Wheel Cylinder The wheel cylinder is responsible for pushing the brake shoes against the drum. If it leaks or fails, it can result in one or both drums not engaging properly. Look for signs of fluid leakage around the wheel cylinder.

4. Improper Adjustment Drum brakes must be correctly adjusted to function effectively. If the shoes are too far from the drum due to improper adjustment, they won’t make adequate contact to slow the vehicle down. Some vehicles have self-adjusting mechanisms, while others require manual adjustments.

5. Drum Damage Any surface irregularities, such as scoring or warping of the drum, can lead to brake performance issues. An unserviceable drum should be replaced or machined to ensure proper contact with the brake shoes.

6. Weak Springs The springs in a drum brake system are crucial for retracting the shoes after braking. If these springs are weak or damaged, the shoes may not retract properly, causing them to drag against the drum.

7. Brake Fade If you’re experiencing a decline in braking performance even after initial engagement, it may be a case of brake fade. This phenomenon occurs when excessive heat builds up in the braking components, reducing friction and effectiveness.

Troubleshooting Steps

If you find that your rear drum brakes are not working correctly, consider following these troubleshooting steps

1. Visual Inspection Start by visually inspecting the brake components. Look for obvious signs of wear, fluid leaks, or contamination.

2. Check Brake Fluid Ensure that the brake fluid is at the appropriate level and does not appear contaminated. Low or dirty fluid can affect braking performance.

3. Listen for Noises Pay attention to any unusual noises while braking, such as grinding or squeaking, which can indicate issues with the brake shoes or drums.

4. Adjust the Brakes If your vehicle has manual adjustment capabilities, inspect the adjustment of the shoes. They should be close enough to the drum for effective contact but not so close that they drag.

5. Consult a Mechanic If the issue seems beyond a simple fix, or if you lack the necessary tools and knowledge, don’t hesitate to consult a professional. Mechanics can provide a thorough inspection and service for your rear drum brakes.

Conclusion

Rear drum brakes are reliable components when functioning correctly. However, issues can arise that compromise their effectiveness, leading to safety concerns on the road. Regular maintenance, including visual inspections and timely replacements, can significantly prolong the life of your braking system. If you suspect that your rear drum brakes are not working, addressing the issue promptly can ensure your vehicle remains safe and reliable. Remember, brakes are not just components; they are essential to your safety and the safety of others.