"Tom's Corner Garage: Brake Squeal; Causes and Cures" Edmunds Daily

Tom's Corner Garage: Brake Squeal; Causes and Cures

brake pads caliper and rotor.jpg

This weekly feature for Edmunds Daily about car repair and maintenance is written by Tom Torbjornsen, the popular host of America's Car Show on satellite radio.

Dear Tom,
I had the front brake pads replaced on my 2002 Ford Taurus and they squeal. The shop told me it would probably stop after 500 miles or so. Well, it's been way over 500 miles and they still squeal. What could be wrong?
Cathy from New Brunswick, NJ

Squealing is the result of brake pad vibration. If brake pads are not secured to the brake caliper they will squeal. Have the shop check over their work. They'll most likely find that the pads need to be secured or insulated in order to stop the squeal.

This has been a commonly asked question over the years. Here are a few causes and solutions for brake squeal.

What causes brake pad squeal?
Brake pads squeal because they are not secure or insulated from the brake calipers. When the brakes are applied, a high-pitched vibration occurs and translates into a squeal. Sometimes glazed brake pads or rotors cause squealing. Friction and wear must take place in order for brakes to stop a vehicle. When the pads and rotors are glazed, two smooth surfaces rub together at high speed and high temperature, causing the pads to vibrate and squeal.

How do you stop brake pad squeal?
When brake pads come from the factory they are held securely to the brake caliper by anti rattle clips. In addition, pads are quite often insulated from the caliper seat by insulation shims or silicone. When these components are in place your brakes are quiet. Other "fixes" of brake squeal include trimming the leading edge of the brake pad to stop pad vibration, replacing the brake pads with a softer friction material such as ceramic or Kevlar, and resurfacing the rotors with a non-directional finish. This creates a proper break-in surface for the pads so that they wear evenly. A number of companies have come up with anti-squeal solutions. You simply apply the chemical to the new pads after scuffing them up (before installation). Let it soak into the pads, then re-apply. These products condition the pads so that they wear evenly on the rotor face and they don't harden and vibrate.

More about ceramic brake pads
Ceramic brake pads were designed originally for the truck market. Brake manufacturers wanted a brake pad that would hold up to the rigors of truck operation (high temperatures, frequent stop-and-go traffic, heavy loads). In addition, brake manufacturers wanted to stop the heavy, black, brake dust that came off traditional semi-metallic brake pads during the stopping process. Finally, they wanted to stop the excess rotor wear typically associated with semi-metallic brakes. Ceramic brake pads addressed all these concerns. They are cleaner, quieter, more durable, and dissipate heat much faster than semi-metallic brakes. With so many benefits in the design, many brake manufacturers now produce ceramic pads for the new car market as well.

'Til next time...Keep Rollin'