Worn Brakes Frays Driver Safety

You're driving down a steep mountain pass in the middle of summer and apply slight pressure against the brake pedal. As your vehicle approaches a curve, you push down harder but your brakes don't respond properly.

"Heat build-up makes the braking system less effective," said Tony Molla, vice president of communications at the National Institute for Automotive Service Excellence. "It could get to the point where the brakes don't work at all, especially if your brake pads are worn down."

Drivers who 'ride' their brakes—keeping slight pressure against the brake pedal as they drive—do not give the system a chance to cool. Brake pads become spongy and wear down faster.

"Drivers should always get their brake system inspected before going on vacation," Molla said. "You don't want to get stranded in the desert or on a remote mountainside."

Stop-and-go city driving also wears out brake pads faster than freeway driving, Molla said. Other factors affecting wear rate include hot driving conditions, frequent use, a heavy foot on the pedal and types of materials used in the brake pad composite.

"If you hear any kind of grinding noise during braking, pull over and park your car immediately," Molla said. "Otherwise you could cause expensive damage."

He also offered the following suggestions for brake maintenance:

• Get your vehicle's braking system checked before going on vacation, especially if you are traveling to a remote spot. Have your mechanic look for pad wear, leaks and a worn or scratched brake disk.
   
• Brake pads usually need replacing every 20,000 to 40,000 miles. Longevity varies by how and where you drive. For example, stop and go city wears out brake pads faster than freeway driving. Check the owner's manual for manufacturer's recommendations on brake replacement.
   
• Use replacement brake pads that meet manufacturer's recommendation. Pad quality varies depending on their composite materials—metal fibers, rubber compounds, silicate and resins. Truck pulling trailers usually require stiffer, larger pads than passenger vehicles. Brakes for high-speed freeway driving need to absorb more heat but generally costly more and wear out faster.
   
• Ask about resurfacing the rotors if your vehicle has been driven more than 70,000 miles. Extremely worn brakes can scratch or gouge the disc and reduce braking effectiveness. Most brake replacement involves smoothing out the rotor surface for improve braking.

"If brake pads get too worn down, metal inside them can cause permanent damage to the rotor," Molla said. "Rather than a minor brake repair, you could end up needing an expensive brake system repair."