First, Just replacing rotors is not enough. In the real world, you have many variables that affect brake rotor performance. Over zealous techs with STRONG impacts over torque wheels. I wish it were not so, but it happens too frequently. Customers also do not tighten to specification, but stand on the breaker bar and bounce to make sure it is good and tight! This is a major cause of distortion of rotors, hubs and wheels.
Sometimes even the hubs are damaged and their run-out is not longer in factory specification. Other factors are corrosion, pot holes and curbs, etc... All these add up to minor deflections in the hub of the vehicle. Sometimes you can clean the corrosion away, but more often then not, once the rotor is attached to the hub and torqued to specification, run-out will NOT be within factory tolerances. The result? You will have brake pulsing before you next brake service, shorter pad life, and increased service costs.
Some shops say new rotors will solve the problem. Not True. New rotors will not guarantee the runout is within specifications. The only way to guarantee proper runout is employ a Rotor Matching System or RMS.
Also rotors found within machinable specifications and have runout problems often must follow elaborate procedures that include indexing, shimming and even trying to match the runout to the bench lathe in an effort to minimize on the car runout. I personally do not know of one shop that goes to half of the necessary effort to ensure rotor runout is in manufacturers specification. The do not have the time, and you wouldn't want to pay for it. But there is a better way.
If you want the best rotor finish available to a specification equal to or better than manufacturer specifications, know that TASC has invested in the best available technology, the Pro-Cut On The Car Brake Lathe with Certified RMS technology. Anything less is a loosing gamble.
