You replace rotors when they get too thin, or are warped. They may be to thin to be turned and still alright to use. Rotors do not "have to" be turned to put new pads on.
brake pads are worn to the metal rivets. You will need to replace pads and rotors. rotors are $35 each and pads are $29-59 for both left and right side.
If they have enough thickness left to still be above legal minimum thickness after the resurfacing, yes.
When the shoes/pads have less than 10% of lining left. When shoes/pads are cracked or damaged. When the drums/rotors are replaced.
First remove the right and left tires, and then proceed to remove the rotors. After you have replaced the rotors put them back on.
no unless they're drilled rotors which are on the very high end of the rotor market
warped brake rotor or drum The shaking can be caused by the rotors being warped out, it can be fixed by ither get the rotors machined "turned" if there is enough metal on it the mechanic will measure it before he turns it, if it do not meet the thickness requirement, then you must replace both rotors, left and right along with the brake pads too, and also I highly recommend to replace the brake calipers too, since they also can be worned down to where it can be a hazard, and to have your brake lines and master cylinder cleaned and flushed out. Also have your back brakes check out too along with the drums or rear rotors too, and also I recommend to replace the brake cylinder or calipers which ever the case might be.
The pads need to be changed when they wear out. That is determined by how you drive. Can be as little as 20,000 miles or as high as 60,000 miles. Once you hear the warning signal, (Squeal) that the pads need replacing, if you immediately replace them you can easily have the rotors trued and not have to replace them. If you ignore this warning, you may end up replacing the rotors. Any good machine shop will tell you if they are too thin to turn.
Warped rotors. Driving using the left foot to brake causes the rotors to heat up. Quenching the hot rotors by driving thru water will cause them to warp. The warped rotors cause the pedal to pulsate.
If you mean that the brakes "pulsate" when you apply light to moderate pressure... that's caused by a warped rotor. If a rotor overheats it will warp causing disk brake "chatter". Sometimes the rotors can be turned to make them "true" again, but often you need to replace the rotors. I generally do both front rotors at the same time so that there is no difference between the left and right brakes.
switch sides...ie..take the left and put it on the right side..land right on the left
Some brake pads have a 'squealer' plate attached. This thin plate does not do anything until the pads become badly worn. Then the plate rubs against the rotor, squealing (emitting a high pitched singing noise) letting you know you need to replace the pads - before they damage the rotors. Without this feature, pads wear out then grind deep grooves in the rotors that then have to be resurfaced (ground smooth again if there is enough metal left) or replaced. So getting pads with this feature saves you from having to replace a set of expensive brake rotors.
Some brake pads have a 'squealer' plate attached. This thin plate does not do anything until the pads become badly worn. Then the plate rubs against the rotor, squealing (emitting a high pitched singing noise) letting you know you need to replace the pads - before they damage the rotors. Without this feature, pads wear out then grind deep grooves in the rotors that then have to be resurfaced (ground smooth again if there is enough metal left) or replaced. So getting pads with this feature saves you from having to replace a set of expensive brake rotors.