Answer:
Both technicians A and B are correct
Step-by-step explanation:
Disc brake thickness rotation is a brake rotor condition where opposite faces of the brake rotor accumulate an extra thickness of brake friction material or thinness due to increased wear. A brake rotor that has developed disc thickness variation causes brake pedal pulsation during braking.
Disc brake thickness should not vary more than 0.001" from one spot to another.
Lateral runout or uneven clamping forces are the two most common causes of Disc Brake thickness variation. Therefore,to avoid Disc Brake thickness variation, the clamping force must be very high, a brake booster can be used for this purpose.
Based on all the above theories, it is obvious that both technicians A and B are right.