Why is there a grinding noise when I brake?
A grinding noise under braking is most commonly the brake pads worn down to the point where metal is contacting metal against the disc, though it can occasionally be caused by a stone or piece of debris trapped behind the disc shield. Either way, it's not something to put off — grinding is a sign the braking system needs attention now, not at the next scheduled service.
Is it definitely the brake pads?
It's the most likely cause by far, because pad material is designed to wear down over the life of the car, and the metal backing plate underneath starts to contact the disc directly once the friction material has gone. That contact is what produces the grinding sound, and it usually gets louder and more constant the longer it's left, because the bare metal is now scoring the disc surface every time you brake.
Could it be something else, like a trapped stone?
Yes — a small stone or piece of grit can get lodged between the disc and the backing plate and grind with every rotation of the wheel, not just when you brake, which is one way to tell the two apart. This is a much less serious cause and is often resolved simply by removing the obstruction, but it still needs the wheel off to check properly rather than guessing from the sound alone.
Is it safe to keep driving?
Once a brake is grinding, treat it as something that needs sorting straightaway rather than at your convenience — braking is one of the few systems on a car where "it still works, just noisily" isn't a safe assumption to drive on. Worn-through pads mean reduced braking performance and, if left long enough, damage to the disc itself, which turns a pad change into a more expensive pad-and-disc job.
What happens if I keep driving on it anyway?
The grinding will typically get worse, and the disc surface will start to score and groove under the exposed metal backing plate, which is the difference between a job that's just pads and one that's pads and discs together. Beyond the cost, braking distance and feel can both be affected once it's gone this far, which matters most exactly when you need the brakes most.
Will it fail an MOT?
Worn brake pads and scored discs are exactly the kind of thing the MOT test looks at, and a dangerous fault found at the test means the vehicle must not be driven until it's repaired. It's far better to have it looked at the moment you hear the grinding than to find out about it at the next test, by which point it's had longer to do damage.
What should I do right now?
Stop relying on the car for anything you can avoid, and get it looked at as soon as you reasonably can rather than waiting — this is one of the few "don't leave it" symptoms on a car. Avoid harsh or repeated braking in the meantime if you can help it, since that's exactly what accelerates the wear on an already-exposed disc.
What does ONEFIX do about a grinding brake?
We check the pads, discs and calipers on the ramp and tell you plainly whether it's pads alone or pads and discs together, with a fixed price in writing before anything is touched. Nothing is carried out that you haven't approved, so if it turns out to be the simpler of the two jobs, that's exactly what you're quoted and exactly what you pay for.
How quickly can I get this looked at?
Brake work like this is exactly the sort of thing worth calling about rather than waiting for a routine appointment slot, since a grinding brake shouldn't sit on a waiting list. Get in touch and describe what you're hearing, and we'll get it on the ramp to find out which parts are involved.