When To Replace Brake Pads

There are a number of indicators that let you know when to replace brake pads. It’s important to recognize each of these factors and address any problems as soon as possible. A faulty component in the brake system can ruin other components and will end up costing you more money!

Here are indicators for when to replace brake pads:

Visual inspection. Under normal driving conditions, brake pads should be checked at least once a year. Vehicles under severe driving conditions brake pads should be checked every 6 months. What’s considered severe driving? Constant stop and go driving, carrying a heavy load on a day to day basis or towing a trailer.

The wheel will need to be removed to check the condition of the pads. Most calipers have a inspection hole in them that lets you see how thick the pads are. Some inspection holes really aren’t large enough to be useful, so you might have to look around the caliper to get a good view of the pads. Pads that have friction material less than 1/8” of an inch should be changed. Check the both the inner and outer pad - one side can wear more quickly if there is a problem with the brakes.

Noise. If your brakes make a squeaking or grinding sound, that may be an indication that something is wrong. Many pads have a metal tab attached to one of the pads that contacts the brake rotor when the material wears down to a predetermined depth. This indicator makes a squealing sound to audibly warn you that your pads have worn down and are need of replacement. As the pad material gets thinner, the metal tab will cut a deeper and wider groove into the rotor, possibly ruining it. If the cuts are more than 1/16” deep, the rotor should be replaced.

Grinding noises occur when the pad material is worn down to the pad’s thick metal backing plate. Some pads don’t have metal indicator tabs, so you'll get no warning how much pad material is left. When the pad material has completely worn away, the pads backing plate comes in direct contact with the brake rotor which makes a deep grinding sound. Not only will braking performance be greatly decreased, this metal to metal contact will quickly destroy a brake rotor. You should never allow your pads to get to this point. Periodic inspection can prevent this from happening.

Low brake fluid level. A low brake fluid level can be a sign of when to replace brake pads. As the pads wear down, more brake fluid is needed to push the caliper pistons out farther to stop the vehicle. This causes the fluid level in the master cylinder to drop. This doesn't mean there is a problem however, as the fluid will rise back up when new brake pads are installed.

If you suspect that a low fluid is not from a brake pad wear, be sure to check for a leak in the system.

Decline in braking performance. If your car pulls to one side more than the other while braking, this could be an indication that the pads could be worn down more on one side of the car than the other (due to a problem with a brakes). On sliding caliper types, the caliper may not be “sliding” due to damage, corrosion or lack of lubrication.

The caliper piston could be seizing and not applying sufficient pressure on the pads. Grabby brakes may indicate that the pads have become contaminated with grease or oil and may require replacement if they can't be cleaned. All of these conditions required immediate attention. Any problems with the brakes should be fixed, and new pads for both sides of the vehicle should be installed at the same time.

Dash light. Some cars (found on luxury & European models) have dash lights for a visual notification that one of the pads has worn down. It won’t tell you which pad is worn, so all will have to be checked (start with the fronts). These cars have electrical sensors mounted to the caliper that grounds itself to the brake rotor as the pad gets thin. This grounding causes the dash indicator to light up. Usually only the front wheels have sensors, as they are the ones that wear out the fastest.

Knowing when to replace brake pads and performing periodic maintenance can help prevent brake failure and keep your repair costs down.

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