Owner's Problem Description
The owner of a 2008 Volkswagen Golf reports that the handbrake has become completely ineffective after initially being weak. After tightening the cable, the lever can only be raised halfway, yet the car still rolls on slight inclines. The regular braking system is functioning correctly with new rotors and pads, and there are no visible damages to the cables.
Professional Technical Analysis
The 2008 Volkswagen Golf features a rear brake system that utilizes a combination of disc brakes with an integrated drum parking brake mechanism. Given the vehicle's age and the owner's description of the symptoms, it is likely that the parking brake shoes inside the rotor have either worn down or require adjustment. The proper functioning of the parking brake relies on the actuation of these shoes against the inner surface of the rotor. With the handbrake cable tightened and only allowing the lever to rise halfway, it indicates that the adjustment may not be sufficient to engage the shoes firmly. It’s important to note that the adjustment of the parking brake shoes is often neglected, leading to failure in holding the vehicle stationary on inclines. To diagnose this issue, the rear wheel must be removed along with the brake caliper and bracket to access the rotor. Once the rotor is off, the parking brake shoes can be adjusted using the shoe adjuster until a slight resistance is felt when the drum is rotated, ensuring they do not bind. Considering that the regular brakes are functioning correctly, it reinforces the likelihood that the problem is isolated to the parking brake mechanism. If the parking brake shoes are worn past their service limits, they will need replacement (OEM part number 1K0 609 199 B for the shoes), which typically costs around $60-120 plus labor. Checking the adjustment process should take about 1-2 hours, depending on the technician's familiarity with the system, and should include a thorough inspection of the brake components for wear or damage.
Possible Causes
Most common causes (ordered by frequency):
- Parking Brake Shoe Wear: The parking brake shoes may be excessively worn, preventing them from making adequate contact with the drum inside the rotor. This can lead to reduced holding power, especially noticeable on inclines. The shoes should ideally show even wear and not be below the service limit of 3mm thickness. - Visual inspection shows worn shoes, insufficient contact with the drum when engaged, possible grinding noise during braking.
- Improper Adjustment of Parking Brake: The parking brake may not have been properly adjusted, leading to insufficient engagement of the shoes against the drum. Ensuring proper adjustment is critical for effective operation. - Lever only raises halfway, and adjusting the cable does not improve engagement. No visible damage to the cable indicates a need for shoe adjustment.
- Internal Drum Rust or Damage: Corrosion or damage inside the drum where the parking brake shoes contact could prevent proper engagement and lead to failure. This can occur if the vehicle is exposed to harsh climates without protective maintenance. - Inspection reveals signs of rust or pitting on the drum surface, which could affect shoe performance.
Diagnostic Steps
Professional Diagnosis Process
Follow these systematic steps to accurately diagnose the issue. Each step builds on the previous one to ensure accurate diagnosis.
- STEP 1 - Visual Inspection: Start by visually inspecting the rear brake components, including the parking brake shoes, drum, and cables. Look for signs of wear, rust, or damage to the parking brake mechanism. Ensure the cables are properly connected and not frayed.
- STEP 2 - Remove Wheel and Brake Components: Safely lift the vehicle and remove the rear wheel. Next, detach the brake caliper and bracket to access the rotor. Ensure to support the caliper to prevent strain on the brake line.
- STEP 3 - Adjust Parking Brake Shoes: With the rotor removed, locate the parking brake shoe adjuster and turn it to expand the shoes until there is slight resistance when rotating the drum. Repeat the process, checking the fit frequently until the ideal adjustment is achieved.
- STEP 4 - Reassemble and Test: After adjusting the shoes, reassemble the brake components and wheel. Test the handbrake functionality on a slight incline to confirm that the adjustments have resolved the issue.
