How do i know when i need my rotors replaced?

i know i need my front brakepads changed in my 2002 mustang but does that mean that i need to change those rotors too? is there a way that you can tell? my mustang has 90000 miles on it and from what i know i never had the rotors replaced.How do i know when i need my rotors replaced?
Rotors are so cheap these days that you might as well replace them, they will give a nice smooth but firm feel in the brake pedal. 90000k IS WAY PAST DUE especially if you live in a city.How do i know when i need my rotors replaced?
well the miles says it all, you have gotten the life out of those rotors and if there warped, you can feel it in the pedal or a jerky motion when it stops, you might not be able to resurface them and then its time to changeHow do i know when i need my rotors replaced?
If you havn't abused the rotors with worn pads meaning metal to metal and there are no groves on them you could replace only the pads. I believe there is a tollerance for the rotor thickness. do a search on rotor thickness. best of luckHow do i know when i need my rotors replaced?
The only reason you would have to change the rotors would be because you let the brake pads wear down to the point of damaging them. I, too, drive a Mustang (albeit a '68) and my rotors are about 12 years old. I just had them checked to be sure, and they're fine. Regular maintenance pays off again.

If you can HEAR your brakes when you use them, then I'd definitely replace all. Best to be safe.How do i know when i need my rotors replaced?
First, do they look smooth? No ripples or grooves, just a nice smooth flat surface.

Second, you must measure the thicknesss of the rotor and check that against the specs. for that car. Some times it is cast into the rotor as a discard thicknes. A brake spec. book will also give a %26quot;Machine To%26quot; thickness minimum.

Finally, thickness variation and run out would be another reason.How do i know when i need my rotors replaced?
Well if you know you need pads the odds are you need rotors ,with 90,000 on the car.The rotors they put on cars now are what you call throw aways,or what I like too call them as Ginsue'sJunk.Back in the day you could get them turned down but I bet if you go to your local auto parts there probably pretty cheap.30 or 40 bucks a peace.A good indicator is a pulsation in the break peddle meaning there warped.So even if you get them turned down thinner to clean them up they have a tendancy to warp again quicker due to friction.If you can even get them turned down due to grooving,how warped they are,and the allowed spec to turn them to there thinest.I dont even deal with it anymore.Alot of shops dont even mess with it. The older cars back in the day had really meaty rotors,and made of good steel,making it possible to get a turn down on them.I found it better just to change them under this circumstance.Good luck pretty easy job while you have the calipers off.How do i know when i need my rotors replaced?
If the rotors cannot be turned they must be replaced. The criterion is determined by measuring the thickness. Too thin and they get too hot. It is also necessary to replace in the case of a crack.

BUT new rotors are always better. Get the prices and compare--deducting the cost of turning which the new ones won't need. You may have a little difficult seperating them from the hubs, but you'll manage.How do i know when i need my rotors replaced?
You have to measure them. There are standards for brakes so they don't fade under high stopping speeds. Check the thickness (the throw out standard is stamped on the side of the rotor) and replace accordingly. If you buy new rotors, they would probably last another 90k miles and it would be money well spent.