With all the stop and go traffic in New York City, it is important to have your vehicle’s braking system functioning at peak efficiency. I remember being eighteen, driving my 95′ BMW M3 and hearing that dreaded grinding noise when applying the brakes. I knew nothing of auto repair at the time, I just knew something was not right with that noise. Hopefully, this article can take some of the mystery out of the magic that makes your car stop when you hit the pedal so next time you need brake service you can make a more informed decision.
Most all cars and trucks on the road today use a hydraulic/mechanical braking system. For simplicity’s sake this example will be of a disc brake system. Some older cars have drum brakes all around and many cars use a mix of disc brake on the front and drum brakes on the rear. The difference between drum and disc brakes is the way the hydraulic fluid is used to get the wheels to stop. The majority of your braking is done by the front wheels, which more than likely are disc on your car.
When you hit the brake pedal, your foot, assisted by the vacuum powered brake booster, sends pressurized brake fluid to the wheels. That pressurized fluid uses a caliper to squeeze brake pads around a rotor. The rotor is attached to the wheel, so as the rotor stops so does the wheel. Have you ever had a car that shakes real bad when you hit the brake pedal? It shakes because excessive heat from braking has warped the brake rotor. That rotor can sometimes be “machined” back to a smooth level surface but that machining often leaves the rotor to future warpage, so replacement of the rotor would be the recommended repair.
Over time your cars brake pads wear out. This is by design. The brake pad is made out of a material that is a bit softer than the rotor so that when the caliper squeezes the pads to the rotor it slowly, over the course of tens of thousands of miles, wears the brake pad down. Towards the end of the brake pad’s life there is a little metal tab that starts rubbing on the rotor making an annoying squeal sound. This is by design as well. That little metal tab is called a……you guessed it, a “squealer”. It is designed that way to purposely annoy the driver so they will bring it in for service before it becomes unsafe to drive. If you keep driving like I did in my M3 then you will wear the pad away until it is just the backing plate of the pad rubbing straight on the rotor making a grinding sound and ruining the rotor.
At M-Spec Performance we look over your brakes every time you come in for an oil service. We check to make sure you have plenty of life left on the pads and that your hydraulic fluid is clean. This is all part of our free courtesy digital inspection. It is vitally important as a safety aspect to make sure your brakes are in tip top shape. We care about you and your family's safety. Besides that whether you drive a BMW, Mercedes, Audi, MINI or Volkswagen you want to make sure your vehicle is in proper working order. I hope all of that makes sense. I am being intentionally vague in some places for the sake of brevity, but I can explain in more detail anything you would like in the comments below or if you want to stop by the shop and talk in person. And of course, here are a couple helpful pictures because they truly are worth a thousand words.