Do I need New Brake Rotors?
 

Is there an easy "test" to determine if I need to change my rotors? I am planning on changing my brake pads next weekend and I am just wondering if there is an easy way to determine if I need to change the rotors also...... I purchased my 2001 Boxster when it had 42,000 Miles on it, it has always been serviced by the Dealership, It now has 72,000 Miles on it and this will be the first time any work will be done on the vehicle not at a dealership.

As a rule of thumb, you need to replace the rotors every other pad change. Pads avg. maybe 35k mi. so at 70k mi. you're likely due.

Or you can use a micrometer and check their actual thickness. Rotor wear limit for the Base model is:

• Front 22.0 mm
  Rear 18.0 mm

For the 'S' model :

• Front 26.0 mm
  Rear 22.0mm

If you don't own a micrometer, a cheap plastic vernier caliper (available at any Lowes, Menards or Home Depot for <$10) could be a substitute (though a less accurate one). Just be sure to take measurements at several places around the Disc and account for any 'lip' which may have developed from wear.

Finally, if your discs just make the limit, but you're replacing the pads, replace the discs anyway because the new pads will quickly wear the discs below the minimum and reduce braking effectiveness considerably. Like it or not, discs are a consumable and part of the price of admission.

PS Be sure to flush and replace the Brake Fluid if it's been 2 or more years, in a climate as humid as New Orleans, that's the maximum I would go w/o changing it (which also happens to be the maint. spec.).