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・Save up to 30%

Get a quote

What others are asking

Q: Won't start makes ticking sound someone said it could be battery or starter but all the lights come on

This is a common sign of a faulty starter solenoid. The starter solenoid is located on the starter and has internal electrical contacts that transmit electricity to the starter. When this fails, it may cause a clicking sound and will...

Q: Brake pedal has too much play.

Brake issues are always a big concern for any driver. I am going to assume from the description provided that both the front and rear brakes were replaced on your vehicle. If, despite these new parts, you are still experiencing...

Q: Whooping noise when brakes are applied

Try rotating the tires to see if the tires have a small flat spot. If the noise moves to the front then replace the tires. If the noise stays in the back then have the brake rotors resurfaced or replaced...

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...
How to Renew Your Car Registration in Oklahoma(DELETED)
Having your car registered with the Oklahoma Tax Commission is an important part of driving legally in this state. You will need to do this within 30 days of moving to Oklahoma...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...