Metal-on-Metal Brake Grinding
Metal-on-Metal Brake Grinding means the friction material is gone and the backing plate is contacting the rotor or drum Because braking problems affect stopping distance and control, confirm the cause before normal driving.
Can I Drive?
stop-driving
Most Likely Causes
- 1
Hydraulic pressure loss or restriction
Brake fluid leaks, blocked hoses, or internal restrictions can change brake pressure and cause pull, fade, or weak braking.
- 2
Worn, overheated, or contaminated friction material
Pads, shoes, rotors, or drums can wear unevenly, glaze, overheat, or become contaminated with grease/brake fluid.
- 3
Sticking caliper, wheel cylinder, or hardware
Slides, pins, pistons, clips, and springs must move correctly. Sticking parts can cause drag, noise, pull, or overheating.
- 4
Improper previous brake work or wrong parts
Incorrect hardware, missing clips, twisted hoses, wrong fluid, or poor bleeding can create symptoms after service.
How to Diagnose It
- 1
Check brake fluid level and visible leaks
Inspect the reservoir, master cylinder, lines, hoses, calipers, and wheel cylinders for low fluid or wetness.
Tool: Flashlight
- 2
Inspect friction parts and hardware
Check pad/shoe thickness, rotor/drum condition, hardware placement, caliper slide movement, and signs of heat damage.
Tool: Jack stands, basic tools
- 3
Road-test only if braking is safe
If the pedal is firm and no leaks are visible, test in a safe area for pull, noise, fade, vibration, or drag. Stop if pedal travel increases.
Tool: Safe test area
How to Fix It
Repair the confirmed hydraulic or mechanical fault
Replace the leaking, sticking, restricted, or damaged part found during testing, then bleed or adjust the system correctly.
Service worn or contaminated friction parts
Replace pads/shoes and rotors/drums as needed, and install the correct hardware.
Flush or bleed the brake system when required
Use the correct DOT fluid and follow the vehicle bleed procedure, including ABS procedures if required.
Mistakes to Avoid
- Do not drive with a sinking pedal, brake fluid leak, or metal-on-metal grinding.
- Do not replace only pads if rotors, calipers, hoses, or hardware caused the problem.
- Do not mix brake fluid types unless the service information says it is compatible.