Common Causes of Drum Brake Grinding

Grinding noises from drum brakes after replacement can be frustrating and concerning. Several factors can contribute to this issue:

Improper Installation

One of the most common causes of grinding noises is incorrect installation of brake components. This can include:

  • Misaligned brake shoes
  • Improperly tensioned springs
  • Incorrectly adjusted self-adjusters

Contamination

Brake dust or debris trapped between the drum and shoes can cause grinding noises. This often occurs if the drums and shoes weren't thoroughly cleaned before installation.

Improper Break-In

New brake shoes need time to seat properly against the drum surface. Aggressive braking immediately after installation can lead to uneven wear and noise.

Faulty Hardware

Worn or damaged return springs, hold-down springs, or self-adjusters can cause shoes to rub against the drum, resulting in grinding noises.

Solutions for Drum Brake Grinding

Inspection and Reassembly

The first step is to remove the drum and carefully inspect all components. Look for:

  • Signs of uneven wear on shoes
  • Damaged or loose hardware
  • Contamination on friction surfaces

Reassemble the brake, ensuring all components are correctly positioned and tensioned.

Proper Cleaning

Thoroughly clean all brake components, including the drum's friction surface and the backing plate. Use brake cleaner to remove any grease, oil, or debris.

Adjustment

Properly adjust the brake shoes to ensure they make even contact with the drum. This typically involves:

  • Setting the correct clearance between shoes and drum
  • Adjusting the self-adjuster mechanism

Break-In Procedure

After installation, perform a proper break-in procedure:

  • Drive at moderate speeds
  • Apply gentle, gradual braking
  • Avoid hard stops for the first 200-300 miles

Quality Parts

Use high-quality brake components from reputable manufacturers. Cheap or ill-fitting parts can lead to persistent noise issues.

When to Seek Professional Help

If grinding noises persist after attempting these solutions, it's best to consult a professional mechanic. The issue could be related to:

  • Damaged brake drums
  • Faulty wheel bearings
  • Bent backing plates

A trained technician can diagnose and address these more complex issues.

FAQs About Drum Brake Grinding

    • Can I drive with grinding drum brakes?
      It's not recommended. Grinding can indicate serious brake issues that compromise safety and can lead to more expensive repairs if ignored.
    • How long should new drum brakes last?
      Properly maintained drum brakes typically last 30,000 to 70,000 miles, depending on driving conditions and habits.
    • Are squealing and grinding noises the same?
      No. Squealing often indicates worn brake shoes, while grinding usually suggests more severe issues like metal-on-metal contact.