What are brake pads?
Brake pads are vital, because without them your car simply won't stop when you want it to. These pucks of high-friction material are installed in the brake calipers and squeezed against the brake rotors by hydraulic pistons, which are moved when brake fluid is forced against them by the master cylinder as you press the brake pedal.
Back in the day, brake pads were made out of mostly asbestos, but they no longer are after, you know, cancer worries. Nevertheless, brake dust will still do you more harm than good, so you should never clean it off with compressed air. Even carbon ceramic and metalic brake pads leave dust that will irritate your lungs and could do worse.
Why brake pads need replacing
Safety-critical is one way to describe your car's brake pads, and that's why they should be maintained to avoid a potential disaster. If the pads wear down to the backing plate, your car won't stop as quickly as you want it to, which could ruin both your day and that of anyone ahead of you.
The friction material on the pads does, in time, wear down. You'll need to replace them before the steel backing plates rub the rotors, or you will quickly need to replace the discs as well.
Some cars have brake pad wear indicators, which activate a light on the dashboard when the pads need replacing. A simpler wear indicator is a little metal tab that hits the rotor and starts to squeal when they are 75% worn out. Another way of telling how worn the pads are is to examine the level of fluid in the brake fluid reservoir (which drops as the pad wears).
Haynes recommends inspecting the pads and measuring the wear whenever you have the wheels off to rotate the tires. This task requires some experience, but uses basic tools, and will take just a minute per wheel.
Every car is different, so before you view the full instructions, find yours…
When to change your brake pads
“Check the edge of the pad inside the caliper for an indication of how worn they are”
Your front brake pads must be examined whenever the car is serviced and replaced when necessary. Yes, many cars have various sensor and wear indicators, but the best way to know for sure is to jack up the car, remove a front wheel and examine the pads directly. Always check the rest of the brake system when replacing the pads; if the discs/rotors are worn thin, grooved, or warped have them machined smooth or consider replacing them.
Check the condition of the pads any time you rotate the tires. A set of front brake pads should last as long as your tires, if not longer, but it very much depends on how you drive and what sort of pads you use.
Before you begin
Each brake caliper has two pads and it’s important to change the pads on both front wheels at the same time, to ensure an even braking force. At the same time, you should examine the rotors and replace them if needed.
Tools you will need
Only basic tools are required for this job, although you’ll also need a C-clamp or piston retraction tool. You will need to raise the car and support it on jack stands.
- Floor jack and jack stands
- Lug wrench
- Ruler to measure pad thickness
- Aerosol brake cleaner
- Wire brush
- C-clamp or piston retraction tool
- Ratchet and socket set
- Torque wrench
Parts you may need
- Brake pads
- Pad clips/springs
- High-temperature grease
- Brake fluid
Every car is different, so before you view the full instructions, find yours…
