ASE G1 Auto Maintenance and Light RepairBrakesHard
A technician observes that the parking brake lever on a vehicle pulls up excessively high, yet the parking brake barely holds the vehicle. What is the MOST likely cause?
- AA faulty parking brake shoe adjuster
- BA seized parking brake caliper
- CA broken parking brake cable
- DExcessively worn rear brake shoes/pads
Show answer & explanationAnswer & explanation
Correct answer: D. Excessively worn rear brake shoes/pads
If the parking brake lever pulls up excessively high but doesn't hold, it indicates that there is too much slack in the system. While a faulty adjuster (D) could contribute, the most fundamental cause for excessive slack and poor holding power in both drum and disc parking brake systems is excessively worn friction material (shoes or pads) that the parking brake mechanism acts upon.
Why the other options are wrong
- A. A faulty parking brake shoe adjuster (specifically in drum-style parking brakes) would prevent the brakes from self-adjusting, leading to increased lever travel and poor holding, but this is a consequence of or exacerbation of worn friction material.
- B. A seized parking brake caliper would likely cause the brake to remain engaged, or prevent it from engaging at all, not allow excessive lever travel with poor holding.
- C. A broken parking brake cable would result in the parking brake not engaging at all, and the lever would likely pull up with no resistance, not just 'barely holds'.
Parking Brake Excessive Travel
A condition where the parking brake lever or pedal travels beyond its normal range, often indicating a need for adjustment or replacement of worn components.
- Commonly caused by worn brake shoes/pads or stretched cables.
- Can also be due to a faulty adjuster mechanism.
- Leads to reduced parking brake effectiveness.
Memory trick: Slack in the line, like a loose rope, means worn parts.