What Is Brake Pad Glazing And How Does It Happen?

Most modern vehicles rely, at least in part, on disc brake systems. These systems consist of a hydraulic master cylinder, fluid lines, rotors, brake calipers, and brake pads. The brake pads feature a layer of friction material, commonly made of metal or ceramic. The master cylinder is responsible for pressurizing hydraulic fluid and sending it to the brake calipers, which then use that hydraulic pressure to compress one or more caliper pistons and push the brake pads into the rotors.

As the brake pads rub against the spinning rotors, they generate friction, allowing your car’s wheels to slow down and come to a complete stop. But while brake pads are designed for this purpose and can withstand immense levels of heat, they aren’t indestructible. They can wear out or become damaged prematurely if you don’t care for them properly. Part of that care involves driving correctly to avoid putting excess stress on the brake system. Overuse or misuse of the brakes can lead to various issues, including brake pad glazing.

This issue refers to the hardening or glazing of the brake pad’s friction material and occurs when the pads are exposed to heat levels that surpass the friction material’s rating. Normal braking activities shouldn’t cause this problem. However, improper braking and bad driving habits, like riding your brakes down a steep hill and slamming on the brakes repeatedly, can create excessive temperatures between the pads and rotors. Glazing is a serious issue and, depending on the extent of the damage, could result in the need to replace your pads and maybe even your rotors prematurely.

You can typically expect glazed brake pads to present a handful of symptoms. However, many of these signs can also be indicative of general brake issues. Poor overall brake performance can point to glazed pads, due to the reduction in friction. You’ll also likely notice vibrations or shudders in your brake pedal, as the glazed pads move unevenly and incorrectly against the rotors. Finally, if you have glazed brake pads, it’s also very likely that you’ll notice your car takes longer to stop than is normal. Because of the reduction in friction between the glazed pads and the brake rotors, your vehicle is going to require a greater distance to slow down and stop. Brake issues are serious and dangerous, and you shouldn’t ignore them.

As mentioned above, brake pads are designed with specific heat tolerances in mind. Depending on the type of pads and their application, there can be significant discrepancies in those heat tolerances between different pads and brands. Generally speaking, the best way to prevent brake pad glazing is to avoid common driving habits that might be damaging your car, like aggressive driving, riding your brakes, or repeatedly slamming your foot onto the brake pedal with too much force. It’s also critical that you service your brake system properly. While poor driving habits are the most common causes of glazed brake pads, damaged or malfunctioning calipers can also cause the issue. However, if you inspect and service your brakes regularly, you should be able to catch any problems before they develop into something more serious.