I don't know if it's just in my mind, but I swear my brakes are less sensitive now after checking my engine and cabin air filters. Feels like I have to press down a little harder to slow down. Also, when is it time to change the brake pads? When they begin to squeak while braking? I think I'm starting to hear some squeaking, but I'm not 100% sure if it's my car or ones around me. I probably sped up the process when I drove with the parking brake on when I first got the car. Stupid noob mistake. Luckily, I didn't drive too far. Thank goodness for the warning sound or else I would've drove home that way.

 

Parking brake is a separate drum brake inside the rear discs. Driving with it on does not wear the rear pads. If the parking brake still holds, you haven't ruined anything. In fact, some guys drive with it on to break in the friction surfaces and make it grab even better (just don't get it too hot).

You can't be sure your pads are spent until you pull the wheel off and check the pads. If you have standard calipers, you unbolt the bottom caliper bolt and flip the caliper up. Then you can pop the pads and check them. They don't always wear perfectly even, it's best to pull each one out and check.

For the brembo calipers, you can remove the wheel and view the entire outer face of the pad through the opening in the caliper (pointing towards the front of the car). If you want to remove the pads, you have to knock the retaining pins out with a punch and remove the plate-spring.

Once the friction material gets down to 1.6mm (.06") thick in the thinnest spot, it's time to replace them. This doesn't include the steel backing plate.

 

Maybe I'll do this step later on. I don't even really know how to take my wheels off.

Anyone have an explanation for the brakes needing more foot stomping to stop? I swear I used to do a light tap and it would start to slow down. Now I have to do like press half way at least to notice a slow down.