As the only thing that will stop your car in case of an emergency, brakes are a pretty big deal. But because we use them daily, we might overlook testing them. It's important not to get complacent, however - brake pads wear over time, so you might not notice the gradual decline in their effectiveness. When you press down on your brake pedal, the fluid causes pistons in the caliper to press the brake pad against the brake disc, slowing down your car. The harder you push, the tighter the pistons squeeze, and the faster your car comes to a stop.

The only way you can be sure when you need to replace your brake pads is by checking them regularly 

Just like every piece of machinery, brake pads wear with use. General wisdom states that you should replace your brake pads every 30,000 miles, while brake discs can last up to double this time. However, there are no magic numbers in car maintenance, and the only way you can be sure when you need to replace your brake pads and discs is by checking them regularly.

How to Check Your Brake Pads

While a number of new models have brake pad wear sensors, automatically giving drivers a warning when the pads reach enough wear to need replacing, not every car has this not-always-reliable system. The warning system is only effective when brake pads wear evenly, but brake pads don't always deteriorate in the same places. The following are simple ways you can check the effectiveness of your brake pads:

1) Pay attention to what your brakes are trying to tell you

Listen to your brakes. Feel your brakes. Many brakes are designed to squeal when the brake pad gets too thin, while if you feel you’re exerting more pressure than should be necessary to bring your car to an immediate stop, it’s likely your brake pads are worn down. If you push the brake to the floor, the car should come to an immediate stop. If your car pulls to one side when you’re coming to a stop, your brakes pads have worn unevenly. Replace both brake pads to avoid this problem in the future – even if one is significantly more worn than the other, the slightly-worn brake pad will wear faster than the brand-new one you’ll be installing. If your brake pads are showing signs that they might need a bit of TLC, take your car to a trusted garage to have your brake pads inspected. Alternatively, take a look at them yourself,  following the instructions below.

2) Look under the wheel

Remove your car's wheel to see the brake rotor and caliper, and, through the hole in your caliper, the brake pads. You can use a compass to measure the width of each side of the brake pads. If the pads are less thick than 6.4mm, they need to be replaced soon; but if they are any thinner than 3.2mm, they must be replaced immediately. Not only are these brake pads unsafe, but they can also cause permanent damage to your rotors. Matteo Everett Photo credit: 'Winter' by Perfect Zero on Flickr (Licence)