Car Care Tips

Tips to keep your car on the road.

Maintenance February 8, 2018

How Do I Know When I Need New Brakes?

A question Virginia Tire & Auto experts are asked regularly is, “How many miles will I get out of my brake pads?” This is not an easily answered question. The fact is that the longevity of brake pads truly varies by driving style and vehicle type.

Brake pads wear with each and every push of the brake pedal. So, if your commute consists of a lot of traffic or city driving then your brake pads are likely to wear out sooner than expected.  

How Brakes Work

Let’s start with the ins and outs of brakes.  They are one of the most essential components of your vehicle.  After all, if they stop working, your vehicle will, too.  That’s an accident waiting to happen.

When a car is in motion, it possesses kinetic energy, or the energy of motion.  By using friction, the brakes decrease the kinetic energy by turning it into heat, which slows, and ultimately stops, the vehicle.

When you, the driver, press your foot down on the brake pedal, a connected lever pushes a piston into the master cylinder, which is filled with hydraulic fluid. That hydraulic fluid then goes through a system of pipes into a set of wider cylinders next to the brakes on each wheel.  This hydraulic system takes the force of your foot on the brake pedal and multiplies it into enough force to apply the brakes and make the car stop.

Types of Brakes

There are two types of brakes – disc and drum.  Many cars have disc brakes on the front wheels and drum brakes on the rear wheels. More expensive vehicles may have disc brakes on all four wheels. Only very old or very small cars tend to have drum brakes on all four wheels.

Disc brakes are made up of a brake disc, a brake caliper, and a brake pad. When the brake pedal is pressed down, the hydraulic fluid enables the brake caliper to press the brake pad against the brake disc. The friction generated by the rubbing of the brake pad against the brake disc converts kinetic energy into heat in the brake pad.

Did you know?  Stopping a speeding car can heat the brakes to 950º F or more! That’s why brake pads are made of special materials that won’t melt at such high temperatures.

Drum brakes also use friction but in a slightly different way. Drum brakes consist of a brake drum and brake shoes. The hollow drum turns with the wheel. When you press down on the brake pedal, a hydraulic cylinder pushes brake shoes with friction linings against the inner surface of the brake drum, creating friction. This causes the vehicle to slow down.

When Should My Brakes Be Replaced?

Need new brakes.

Since brakes are so important to a vehicle, your next question might be, “How often should I get my brakes replaced?”  It depends on the make and model of your vehicle and how often the car is driven.  By most industry estimates (which can vary significantly), brakes should be replaced every 20,000-60,000 miles.  Since mileage estimates for brake life can vary greatly, here are some signs of brake wear that drivers should be on the lookout for:

  1. ‘Screeching’ sound when you press the brake pedal.  Many cars have an indicator that creates a warning sound, sending an alert that you need to replace the brake pads.
  2. Additional brake pressure needed to stop the vehicle. This could be an indication of a brake fluid leak and can sometimes be confirmed by the existence of a small puddle of brake fluid under your vehicle.
  3. Your car pulls during braking. Pulling of your car to one side when brakes are applied could be a result of the brake lining wearing unevenly. You may just need a brake adjustment or have the fluid drained and replaced.
  4. Vibration when pressing the brake pedal: This could be a sign of warped rotors.
  5. Grinding noise: The type of sound is usually associated with metal parts rubbing together. It likely is a result of completely worn brake pads that are rubbing into the rotors.

A visual inspection of the brake pads can also highlight wear issues. Normally, you want to measure the thickness of the brake pads and consider replacing them at 3/32 inch thickness or below. Please refer to the picture below for an example of what new and worn brake pads can look like:

*Virginia Tire & Auto can take a look at them for you – we offer FREE visual brake inspections.

Upon Further Inspection

Is your car scheduled for its annual inspection?  If so, here’s what will determine that your vehicle is due for new brakes in Northern Virginia:

  • Worn, damaged or missing parts
  • Worn, contaminated or defective linings or drums
  • Leakage in system and proper fluid level
  • Worn, contaminated or defective disc pads or disc rotors

Dangers Of Riding On Bad Brakes

Do I need new brakes?

For many drivers, hearing the screeching or grinding sounds may not be enough of a problem to take a vehicle in to Virginia Tire & Auto, but if the warning signs aren’t heeded in a timely fashion, the result could be dangerous.

For example, let’s take the brake rotors.  The rotors are part of the disc brakes that allow your vehicle to stop once the vehicle is in motion.  If the rotor is warped, the brake pads will wiggle back and forth, which causes the brake fluid to foam up so the braking system does not get the proper amount of hydraulic pressure. If the rotor is warped, your vehicle may not be able to stop properly in an emergency situation.  Warning signs of a warped brake rotor include vibrations in your brake pedals and noise coming from your brakes.

One of the most common signs that brakes need to be replaced is a grinding sound that happens as you begin to stop the vehicle.  A grinding noise usually happens when the metal pads and metal rotors rub against each other and no braking material is left.  If you don’t get your car in to be fixed when you hear the grinding, you will likely be paying even more the longer you wait.  

Not sure whether or not you need new brakes?

Bring your vehicle to a Virginia Tire & Auto location in Northern Virginia. We offer a FREE visual brake inspection which includes a measurement of the brake pads/shoes and a brake fluid test.

If your brakes need servicing, our expert technicians are equipped to perform any brake repair. Check out our brake services & pricing by clicking HERE.

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