Your Car 101 (Series) - How do I know my brakes need to be changed?

Bad Brakes?  DIY on checking your brakes.

There are two ways you can go about this.  The easiest is to look at your brake reservoir (assuming all other part are working correctly).  Let me explain...

Option 1

Do you remember your first bicycle with the hand brakes?  It had two little pads that pressed against the front or rear wheel.  Your car really isn't that much different.  Each rotor has two pads with it, and the rotor is fixed to your axle.  So when your wheels are turning, so is your rotor.  When you want to stop, the two pads press against each side of the rotor, bringing your vehicle to a stop.  The difference between your car and that bicycle is the car uses brake fluid whereas a bicycle uses a cable.  When you pulled the cable, the two pads would press against the wheel.  When you push your car's brake pedal, you're pushing fluid out of the reservoir, through the brake lines, and telling the brake pads to push against the rotors.  Make sense?  Ok...here's the key factor.

Each time you apply the brakes, you lose a certain amount of brake pad.  Depending on how you drive, it'll be more or less.  However, when you release the brake pedal, the pads only move back from the rotors a certain amount every time.  This is good, because the pads don't have a large distance to travel to slow your vehicle down.  However you have less pad now and less goes back in the reservoir.  Therefore, as the brake pads wear down, so does the fluid level in the brake reservoir.  

Now for the "watch out for"s.  First, remember where the fluid is to begin with.  If you don't, you can't tell if your fluid level is dropping.  Your brake master cylinder is the big part on the back wall which the brake reservoir is attached to.  That could possibly be going bad as well.

Option 2

This is the fun part.  Option two is jacking up your vehicle and removing the wheel and tire.  Once removed, you can look into the brake caliper to view the brake pads.  You can tell with your eyes whether your pads need replacing. 

Option 3

If you have access to a lift, you can put the car in the air without removing the wheels.  Sometimes (especially if you have larger wheels), you can still see the pads.

Recommendations

Do NOT wait too long.  If you hear a grinding noise or feel through the brake pedal that there is metal on metal contact, it might be too late.  See...when the pads get down to the point where the metal in the middle is exposed, the pads then start grinding into the rotors and putting grooves in it.  This is very bad for new pads and will accelerate the wear of any new pads.  Also, with it not being a flat surface, the pads will only come in contact with part of the rotor and that can affect braking distance and capabilities.  The results?  New rotors, which typically starts around $50 each corner.  Changing them on a regular schedule and keeping an eye on the pad's wear will save you some money in the long run.

- Bryan Lin | CEO, The Motorsports Authority, Inc. | www.MSAStore.com