i have a 2002 pontiac grand am i need to do a front brake job the rotors are at .990 the machine to is .987 the discard thickness is .972 can i use these rotors again being so close to the discard thickness
I recommend new rotors. If you machine the old ones they will be near the minimum thickness and will be prone to warping, at which point you’ll need new rotors. Just bite the bullet and install them now.
Consider the cost of new rotors and the cost of machining old ones. Go for new, today’s cars have rotors that are really intended for single use, but sometimes you can get two uses from them. (IMO)
As long as they are ABOVE the thickness it’s fine.
The rough cut will have you well below the machine to thickness and the finished product will be very near the discard spec, unless you have any pulsation whatsoever, in which case it will be below discard. Go with new rotors. They are dirt cheap for this car.
I’d go for new rotors. You are soon due for them anyway.
Recent personal experience confirms recommendations to get new rotors.
I did brake job on my '02 Grand Caravan, and had the rotors turned. Within 4-5 months had warped front and back rotors. Ended up paying for turning the old rotors plus buying new ones.
If your brakes do not pulsate felt at the pedal or by you and your passengers either at high speed or when nearing a stop, you might be OK with organic brake pads which do not wear rotors as much semi-metallic pads. Organic pads might be more difficult to find and may wear out faster.