What Your Vehicle Brakes Can Tell You
Find Out What Your Brakes Are Telling You
If you drive, you may know that at times your brakes may make a noise, feel weird, or just make you think "uh...what was that?" Well here is some useful information on what your brakes may be telling you.
How Brakes Work
First, let's learn how brakes work. Brakes work by converting friction into stopping power.
- You push on the brakes.
- The brake fluid goes through the brake lines and pushes the brake calipers;
- The calipers push the brake pads or shoes onto your rotors or drums and cause them to stop spinning.
It's just like running something between your hands: if you hold it loose or not at all, it moves freely, but the more pressure you put on it, the more it slows down and eventually stops. So that's how brakes work.
Now that you know how they work, let's talk about what happens if there is a problem with your brakes. If you have a leak of fluid in your braking system, then air gets into your brake system and causes the brakes to feel mushy, because unlike fluid, air can be compressed. It's what Bernoulli was talking about when he was saying fluid can move things by applying pressure to them because fluid doesn't lose any force. So if you have air in the system, then the brakes won't apply the same pressure your foot does.
Also if your brake pads or shoes don't have enough material left on them, they will take longer to respond, because it takes a longer time for the pads to hit the rotor or drum. So that's what happens if there is a problem.
So now it's time to talk about what your brakes tell you when something is wrong. Here are some noises brakes make and what they usually mean.
Grinding or scratching often means that all the brake material is gone and now the metal plate that holds the pad is rubbing against the rotor. This is very bad, because now you have no braking material and the two pieces of metal rubbing against each other can melt and cause your brakes to stick. After that happens, you will have to pay for new rotors or drums as well as new brake pads or shoes, because the damage to the metal rotors or drums can't be repaired. To avoid this, you should replace your brakes when the material is 3 mm thick or less on pads and 1 mm on shoes.
Loud screeching or high-pitched noises often mean your rotors are glazed. Glazing is caused by excessive braking; the rotors get too hot and scorch. You can tell this has happened because the rotors will have a dark ring or blue marks on them. To fix this, the best thing to do is create a new rotor surface by machining your rotors at a local shop. Smoothing the surface should cause the noise to go away.
To avoid this happening at all, don't go really fast and then slam on the brakes. This causes a lot of friction which turns to heat and causes the burn on the rotor. It can also cause the rotors to warp which can lead to vibrations.
Vibration while braking often means your rotors or drums have been warped. This is caused by heat making them lose their shape. If your rotors or drums got warped because they were too thin, they will need to be replaced. But if they warped just because they got too hot, then all that needs to be done is that they need to be resurfaced by a local shop.
If you want to know whether or not the vibration is coming from the front or back brakes, you can drive down the freeway and push the brakes until you feel the vibration. If you feel the vibration in the steering wheel, the problem is in the front, because the vibration is transferring from the front wheels through the steering linkage. If you want to check the back brakes, then apply the parking brake just slightly while driving, and see if you feel the vibration in the car in general and not just the steering wheel.
Brake Pull is when your vehicle pulls to one direction when you brake. This can be caused by your brake caliper not applying the brakes evenly on both sides. It's usually a result of a fluid leak in the caliper. To know which side it is, you'll just have to look at the brake caliper and see which one is leaking; this usually should be done by a professional. To fix this, you will have to replace the caliper and bleed the brakes of all the air in the system. There is no real cause for this besides just normal wear.
So these are the most common problems with brakes besides normal wear. So next time you're driving and you hit the brakes and they start talking to you, you'll have a better idea of what the problem is.
Be sure to consult a professional before trying anything yourself because if repairs are done incorrectly, they might cause an accident which could result in injury or death.