Quote:
Originally Posted by 01F250CCLB4X4
FMTRVT In your first post are you saying that most mistake uneven wear for warping? I had Ford's premium pads & rotors and the performance I wanted wasn't there. I switched to a high quality grey iron rotors that are precision machined. I went with a ceramic/carbon fiber pad. They had a brake in material on them and now after about a year and 10,000 miles they are wearing perfectly (look brand new actually). I do a fair amount of higher speed braking and I was looking for performance gain. Did I choose the wrong set up for my needs?
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The pulsation is from thickness variation in the width of the rotor. As you transition from thick to thin you get a variation in pressure and clamping force. As the rotor moves to it's thin area, the pressure drops slightly reducing the brake torque and causing the pedal to slight drop due to the caliper brake fluid volume change. As the rotor travels 90 or 180°, the rotor moves to its thick area and the wedging of the pads produces a higher pressure, an increase in brake torque and a slight pushback of the brake pedal. This is the pulsing one feels in the pedal, steering wheel (if front rotors), and in the body of the vehicle as well.
If the rotors were "warped" 0.005", wouldn't the caliper just move on the slides that amount with the rotor? What if 0.010" warp? The caliper would just move on it's slides again, but with this amount of movement and the quickness of the side to side movement with rotor rotation, the G forces tend to overwhelm the slide hystorisis and pulsing is then felt. But 0.010" runout of a rotor is rarely seen. Rarely, but not impossible.
When you wrote "Ford's premium pads" I'm starting to feel like there is counterman parts speak, like these are the Motorcraft Super Duty line of aftermarket pads, or the step below. To me, the OE pad is the "Premium" pad if I was going to use labels.
With the tire size in your signature, I would not expect any of the Ford pads to do remarkably well with the leverage of the new tire size over the brake size. You did well in your choice of going for higher friction brake pads.
