Grinding Noise When Braking — Causes and What to Do

A grinding or grating noise when you apply the brakes is a clear sign that the braking system needs attention. In most cases it means the brake pads have worn through to the metal backing plate and are now grinding against the disc. The grinding will only get worse with continued use — and the later you leave it, the more expensive the repair.

What Causes a Grinding Noise When Braking?

Brake Pads Worn Through to Metal

This is the most common cause. Brake pads have a steel backing plate and a friction material bonded to it. As the friction material wears down, the wear indicator tab (a small metal clip) begins to scrape the disc — this produces a high-pitched squealing sound. When ignored, the pads wear through entirely and the bare steel backing plate contacts the disc directly, producing the grinding sound.

At this point both pads and discs usually need replacing.

Grit or Stone Trapped Between Pad and Disc

A small stone or piece of grit can become lodged between the brake pad and the disc surface, causing a scraping or grinding sound that may occur with or without applying the brakes. This usually resolves on its own after a few brake applications as the debris is expelled. If it persists, the caliper should be removed and the pad/disc area inspected.

Seized or Sticking Caliper Piston

A caliper piston that sticks in the partly applied position keeps the brake pad in constant contact with the disc. This causes the pad to wear unevenly and rapidly on one side, leads to the disc overheating and eventually produces grinding. The vehicle may also pull to the affected side under braking.

Corroded Discs

Discs that have heavy surface rust (common after the car has been parked for several days in wet weather) can produce a brief grinding sound that clears quickly. Deep rust pitting or corrosion around the disc edges can cause persistent scraping — these discs should be replaced.

What Is Safe to Drive On?

• Brief morning rust scrape that clears — safe to continue driving short-term, monitor
• Squealing that goes away once warm — worn pad indicators, book a repair soon
• Persistent grinding at every brake application — drive only to get the car home, then call us
• Grinding with pedal vibration or vehicle pulling — do not drive; call for a mobile repair

DIY Check

Without removing the wheel, you can usually see the brake pad through the gap between the wheel spokes. The friction material should be at least 3mm thick. If you can barely see any material, it is due for replacement.

How We Fix It

1. Remove wheel and inspect pad thickness, disc condition and caliper
2. Measure disc thickness against manufacturer minimum spec
3. Quote: pads only, or pads and discs, depending on disc condition
4. Replace pads (and discs if required) with parts matched to your vehicle
5. Lubricate caliper slide pins
6. Bleed the brake circuit if the caliper has been compressed significantly
7. Test drive for brake effectiveness

Book Brake Repairs in Reading

Call 07305 523333. We carry a wide range of pads and discs and can usually carry out brake repairs same-day across all Reading postcodes and surrounding Berkshire towns.

Get this fixed by a mobile mechanic in Reading

• Brake Repairs
• Car Diagnostics