Skip the auto shop - Our mechanics make house calls

Q: GRINDING NOISE WHILE BRAKING

asked by on

Grinding noise mostly from the rear while braking even at low speeds. What need to be replaced? Pads? Rotors?

My car has 78000 miles.
My car has an automatic transmission.

A: This may be a sign of warped brake rotors. ...

This may be a sign of warped brake rotors. As you may know, when you press on your brake pedal, this activates a hydraulic pressure which forces small pistons inside your brake calipers to push the brake pads against the brake rotors which is what causes the stopping power you are familiar with. When this happens, an enormous amount of heat is generated due to the friction between the brake pads and rotors. As the brake rotors eventually cool down and then heat up again the next time you press on the brakes, over time this can cause them to warp slightly causing very small low spots on the surface of the brake rotor. When this happens and the brake pads are applied again to the rotors, this causes an uneven surface (on the rotor) to be applied to the flat surface brake pad, which can cause a vibration, shaking or very loud grinding sound. I would recommend having an expert from YourMechanic come to your location to diagnose and replace your brake rotors.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Vibration and dying at red light

Hi There, It sounds like you may have two separate issues. You may have worn out brake rotors which may be causing the vibration when you use the brakes. As you may know, when you press on your brake pedal,...

Q: Replaced brake pads, but tires sqeak when I stop

One common mistake that can be made when replacing brake pads is forgetting to spray the brake rotors down with brake cleaner before installing them. This applies to new and used rotors: New rotors have a sticky adhesive...

Q: I want my car repaired but not sure what the problem of th e car is. lately when i start the car it just makes a grinding noise an

If you have confirmed that there is a loud grinding noise on starter activation, that means one thing and one thing only: the starter motor is failing, likely due to an internal fault such as a bad starter drive gear,...

Related articles

How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...