Brakes wear out slowly, and they usually tell you about it well before they become dangerous. The useful skill is knowing which noises are normal, which ones mean book an appointment, and which ones mean stop driving the car.
1. A squeal that doesn't go away
A light squeal or scrape on the first few stops of a damp morning is normal. Moisture leaves a thin layer of surface rust on the rotors overnight, and the pads wipe it off within a few stops.
A high-pitched squeal that happens every time you brake, and keeps going after the car is warmed up, is different. Many pads have a small metal tab built in that rubs on the rotor when the pad gets thin. It's designed to be annoying. New pads typically start with around 10 to 12 mm of friction material, and most shops recommend replacing them at about 3 mm. If you hear the wear indicator, book an inspection in the next week or two.
2. Grinding
Grinding, or a harsh metallic growl when you brake, usually means the pad material is gone and the steel backing plate is rubbing on the rotor. Every stop from here cuts into the rotor, turning a pad job into pads and rotors, and stopping distances get longer. This one needs attention right away, not at the next convenient weekend.
3. Vibration when you brake
A pulsing in the brake pedal, or a shimmy in the steering wheel when slowing from highway speed, usually points to the rotors. People call it warped rotors. More often the rotor has developed uneven thickness, from uneven pad deposits, rust patches or wheel nuts tightened unevenly. Depending on their condition, rotors can sometimes be resurfaced. Often they're replaced along with the pads.
Don't confuse it with ABS. A rapid buzzing pulse through the pedal during a hard stop on snow or ice is the anti-lock system doing its job, and that's normal.
4. Pulling to one side
If the car pulls left or right only when you brake, one side is braking harder than the other. Common causes are a sticking caliper, seized slide pins, a collapsed brake hose or a pad contaminated with grease or fluid. A sticking caliper often comes with a hot, burning smell after a drive, and more brake dust on that wheel than the others.
If the car pulls all the time, not just under braking, check tire pressures and alignment first.
5. A soft, low or sinking pedal
The brake pedal should feel firm and stop at the same height every time. If it feels spongy, goes closer to the floor than it used to, or slowly sinks while you hold it at a red light, there may be air or moisture in the fluid, a leak, or a problem with the master cylinder. Treat this one as urgent. A change in pedal feel is the most important warning on this list.
Brake fluid absorbs moisture from the air over time, which lowers its boiling point. Many manufacturers call for a brake fluid change every two to three years. Check your owner's manual for yours.
6. A warning light or a leak
A red BRAKE light with the parking brake fully released usually means low brake fluid or a fault in the system. Brake fluid doesn't get used up. The level drops slowly as the pads wear, and quickly if there's a leak. A small oily puddle near a wheel, clear to light brown in colour, needs a look before the car goes much further.
An amber ABS light is less urgent. The anti-lock system is off, but normal braking still works. Brake gently on slippery roads and book it in.
Salt is hard on brakes
Toronto winters add their own problems. Road salt gets into caliper slide pins and pad brackets, and parts start to seize. When that happens, the inner pad can wear down to metal while the outer pad, the one you can see through the wheel, still looks fine. Rotors rust on their faces and edges too, especially on cars that sit for days at a time.
- Have the brakes inspected with the wheels off at least once a year.
- When pads are replaced, the slide pins and brackets should be cleaned and lubricated, not just the pads swapped.
- A seasonal tire changeover is a good time for a quick look, since the wheels are already off.
When we inspect brakes, we tell you what we measured and give you a quote before any work starts. If you'd rather wait, we note it on your file and remind you later.
