You can tell if your brake discs are worn by jacking up the vehicle and removing the wheel and physically looking at the brake discs.
Also when brake pads are worn they will make a scraping noise from the wear indicator which is a sign that they should be replaced
If your brake rotors are grooved or warped they should also be replaced.
The symptoms of worn brake pads are scraping or screeching noise when applying brakes, brake pedal going to the floor or near to the floor and metal on metal sound if the brake pads are worn completely.
Or if it takes a bit longer to come to a complete stop when you press the brake pedal down it can be a sign that your brake pads are worn out.
The most common reason for your brake pads to wear out quickly are from lots of stop and go driving, riding your brakes, frequent hard breaking such as at high speeds etc.
If you do hard braking instead of slowly applying your brakes when ready to come to a stop your brake pads will wear out much faster.
Your brake rotors may also be warped or grooved and be causing excessive wear on the brake pads.
Brakes should normally wear down evenly and if they are not wearing evenly then it can be a sign of bad brake rotors or brake drums.
Uneven brake pad or brake shoe wear can be a result of metal on metal contact with the brake rotors or brake drums and the brake pads or brake shoes.
Your front brakes are more likely to go out first than your rear brakes as your front brakes do most of the stopping and work to stop the vehicle so naturally the front brakes will often wear faster and need replaced sooner than your rear brakes.
When you apply the brakes the front brakes engage first and then the rear although they do so very quickly that in reality both the front and rear brakes are working nearly at the same time.
But your front brakes do most of the braking and to stabilize the vehicle your front brakes must lock up first and if your rear brakes locked up first it would cause the car or vehicle to spin.
The front brakes of a vehicle do most of the stopping as most of the weight is at the front and the brakes are stopping the car from moving forward so the front brakes do most of the work which means they will also wear out faster than the rear brakes.
80 percent of a vehicles stopping power is supplied by your front brakes which is why the front of a vehicle may dive a little when you apply the brakes.
Front brakes do wear out faster as they do most of the stopping and handle most of the vehicles weight.
In a vehicle that carries heavy loads in the back or pulls a trailer the back brakes may wear out just as fast but in vehicles without a lot of weight in the back or pulling a trailer your front brake pads and brake rotors will wear out faster.
Front brakes should last between 30,000 miles to 80,000 miles although if you do a lot of stop and go driving the front brakes will wear out quicker and may only last 20,000 miles to 30,000 miles.
The symptoms of worn brake pads are scraping or screeching noise when applying brakes, brake pedal going to the floor or near to the floor and metal on metal sound if the brake pads are worn completely.
Or if it takes a bit longer to come to a complete stop when you press the brake pedal down it can be a sign that your brake pads are worn out.
The sound that bad brakes make is a screeching or scraping noise or metal upon metal noise depending on how bad the brake pads are worn down.
The sound of the bad brakes will appear when you press the brake pedal or may continue if your brake calipers are bad or brake rotors are warped.
You can tell when you need new brake pads by looking at them to check the thickness or how thin they've become or by listening for sounds such as a screeching or scraping noise when you brake.
Worn brake pads do make noise and when the brake pads are worn out they will make a screeching or scraping noise from the brake pad itself or from the wear indicator that is designed to make contact with the brake rotor when the brake pads are worn down enough to need replaced.
If you hear a screeching sound or scraping sound when applying your brakes then it's likely time to replace the brake pads as they are worn out.
Brakes and brake pads and brake shoes tend to last between 3 to 5 years depending on how many miles you drive and how often you use the brakes.
Some brake pads may last as long as 6 to 7 years and some wear out sooner if you do more stop and go driving.
When your brakes are going out you will know by the sounds and by the brake pedal which will often go further to the floor.
If you completely lose your brakes then brake pedal will go to the floor and the vehicle will not stop or when the brakes are failing the brake pedal may become spongy or be hard to press in some cases.
If it's your brake pads or brake shoes going bad they will often make a scraping sound or screeching sound when you press on your brake pedal to stop the vehicle.
Brake pads should be replaced before they are as thin as 1.5mm and a new brake pad will be at least 10mm thick.
It's recommended that you replace your brake pads when they are as thin as 3mm in thickness.
You can just replace brake pads as long as the brake rotors are good and the brake calipers are good.
However it's a good idea to replace the brake rotors after every 2nd brake pad change as the brake rotors can also wear down and become thin.
I've always replaced my brake rotors whenever I replaced my brake pads a 2nd time just as preventative maintenance.
I do the job myself though and buy the parts online so I get them cheaper.
Brake pads do need replacing as brake pads are a wear item that wears down the more you use your brakes.
The friction material on the brake pads wear down as they make contact with the brake rotors to stop the vehicle and eventually the brake pads wear down to the metal and won't be able to stop the vehicle.
The brake pads should be replaced when the brake pad material wears down thin and before it wears down completely to the metal.
Brake pads also have wear indicators which is a piece of metal that makes contact with the brake rotor when you press on the brake to stop the vehicle and makes a squealing or scratching noise which means it's time to replace your brake pads.
Most brake pads last between 30,000 and 70,000 miles although some brake pads can last as long as 80,000 to 100,000 miles if you do mostly highway driving.
You should however plan to replace brake pads by 30,000 to 70,000 miles and it's a good idea to inspect the brake pads after 10,000 to 20,000 miles.
Some brands of cheap brake pads wear out faster than others but for the most part most brake pads whether cheap or more expensive wear the same depending on how much you use your brakes.
If you ride your brakes or use the brakes more and do more stop and go driving nay brake pads will wear out faster than those that are on vehicles mostly driven on the highway.
Cheap brake pads can wear out faster than higher quality more expensive brake pads.
However it can also depend on how much you use your brakes to how fast your brake pads will wear out.
I've had some brands of cheap brake pads wear out faster than other cheaper brands of brake pads.