Proper brake inspection and maintenance rank among the most crucial tasks that mechanics or technicians must master. The lifespan of brake pads can significantly differ, highlighting the importance of recognizing when they require replacement.
The 12 Most Important Tips for Thorough Brake Inspection:
1. Heat Cracks:
Inspect brake discs for heat cracks. Discovering any warrants the use of a dial indicator for more precise testing.
2. Brake Fluid Level:
Regularly check the brake fluid’s level and condition. Change the fluid if needed and drain a small amount to enable fluid return from the pistons upon their retraction. Open the brake fluid reservoir cap during piston retraction to prevent resistance and damage.
3. Inspect Adjacent Areas:
When changing brake discs and pads, inspect all neighboring parts and components for wear and damage. This includes steering and suspension parts, bushings, bearings, brake hoses and lines, as well as cables, connectors, shock absorbers, springs, and ABS sensors. Cleaning the brake rotors of excessive corrosion is essential even if only the pads are being replaced.
4. Topping Thickness:
Use a pad thickness gauge to measure wear. It’s commonly advised to replace brake pads when the friction material thins to 3mm or less, though manufacturer guidelines should prevail. Post-ride inspections of old brake pads and rotors should look for signs of overheating and excess dust.
5. Signs of Pad Wear:
Excessive wear on an outer brake pad often indicates issues with guide pins, bushings, and sliding pins. Inner lining wear suggests a seized piston or master cylinder issues.
6. Notes on Lubricants:
Avoid copper-based greases on modern brake pads as they can lead to sticking in the caliper and damage the rubber coating. Opt for Delphi anti-seize brake compounds instead.
7. Anti-noise Pads:
Brake pads’ noise-dampening elements weaken over time, possibly causing increased noise, uneven wear, and braking. Replacing pads or shoes should also involve changing related components like springs, clamps, and washers.
8. Wear of Brake Shoes:
Indications of worn brake shoes include uneven brake pedal feel and vibrations during braking, or an overly long parking brake distance.
9. Check the Springs:
Brake shoe return springs can weaken, failing to return the shoes to their proper position, thus accelerating pad wear.
10. Ensure Proper Lubrication:
Keep the self-adjusting mechanisms of brake shoes clean and well-lubricated.
11. Brake Hose Lifespan:
Made of rubber, brake hoses wear over time and should be replaced upon showing signs of rot, cracks, or narrowing.
12. Brake Fluid Temperature:
Assessing the brake fluid’s temperature helps gauge its water content for optimal performance and efficiency. Regular calibration is essential for reliability.
Additional Advice:
Inform customers to drive cautiously for the first 300 to 350 kilometers with new brake parts, avoiding excessive braking to prevent damage and preserve braking effectiveness. Also, recommend that brake disc or drum replacements be conducted in axle sets to avoid unbalanced braking performance and premature wear.