I'm surprised this was skipped over and not talked about more. 99.99% of the time, its not "warped rotors" (i.e. metal which has heated to the point of losing it's original shape/form) but rather uneven pad material deposits. When this happens, you can usually have the rotors turned (shave a bit off) and re-bed the brakes, or just go through the brake bedding procedure (Google) to evenly distribute pad material again.
If you drag the breaks down a long decline and then sit at a stop light without letting the rotors cool properly, pad material will adhere (melt) itself onto the rotor at that specific spot which can cause the pulsing.
Either way don't spend that kind of $$$. Some Centric blanks and pads should run you less than $300 on RockAuto/Amazon. Take these to a local mechanic if you can't do them yourself and you should get the normal install time which should be 4-5 hours for all 4 corners. Still 1/2 of what you were quoted.
This is exactly right. In a former life I worked for a company that was trying to develop next gen braking products using aerospace type materials. I worked with car companies, brake pad formulators, rotor manufacturers, and even some of the test houses. It was fascinating stuff. A couple things I learned:
1- OEM’s spend millions of dollars to develop and validate a brake system for a platform. Braking systems are one of the most common complaints (noises, pulsing, dusting, etc.). Knowing how much they put into a braking system, I’ve been extremely weary of most generic aftermarket brake pads where the same formula could potentially be made for an Expy and a Honda Civic. That seems unreasonable given how different those vehicles are.
2- brake pads contain a variety of materials: lubricants, fillers, abrasive / friction materials, binders, and thermal management materials. They all react differently in the pads. As of ten years ago phenolic was still common as a binder and that resulted in the horrible smell under extreme braking.
3- the thicker the pad, the more compression it has. As pads wear, there is less compression which creates a stiffer barrier between the rotor and your brake pedal. As pads wear you will notice more imperfections in the rotor surface. Think about new tires vs old tires and how much more you feel from the road as your tires age.
4- braking occurs because a friction layer (called wear debris layer) builds up on the surface of the rotor. This deposit is what creates friction and stops your vehicle. This is why bed in of new pads and rotors is vital to success. Think about how new pads and rotors often lack bite, while broken in pads often have a good initial bite that is easily modulated. Overtime the wear debris layers breaks down and redeposits. This process is what leads to rotor wear.
5- rotors are designed such that it is nearly impossible to physically warp them. Even though automotive companies are making them smaller and thinner to save weight, their design limits do not have a lot of freedom to warp. There are other drawbacks to thinner/lighter though, such as a higher likelihood of brake fade, uneven wear debris layers, etc. Warping is generally not one of them.
6- the pulsing sensation is caused when uneven deposits of brake pad material build up on sections of the rotor surface. This can be caused, as pointed out by others, when a very hot pad is held in place, such as at a stop light. Due to some of the materials used in the pad they will have lower melting points, which causes the material to stick to the pad. This high point on the surface generally becomes a hot point that captures more material. And as your pads wears you have less material to absorb heat, less compression, and thus the cycle builds on itself. You feel more pulsing.
Pad formulators are always trying to balance several characteristics: smooth consistent stopping capability, wear (longevity), noise, dusting, etc. Often times, improving one can have dramatic negative effects on the other. My preference is always to try to make the OEM pads work and improve heat dissipation at the rotor. Cross drilled rotors will tend to eat pads a little quicker but do a decent job of cutting down heat. Some non-drilled rotors do a better job of thermal management than others with venting and materials selection. If you are simply looking for a higher coefficient of friction, this can be achieved, but use a reputable company’s pads. I am not a fan of the lifetime brakes gimmick. They use very hard materials so they wear very little. This in turn eats up your rotors and typically comes at the expense of overall friction performance. In a Civic driven by Grandma, that might not matter. In a 6,000 lb Expy, it does. I’ve always believed that the OEM has the most vested interest in making the brake system work for their vehicle so I’m most comfortable with at a minimum OEM pads. There’s a lot of unknowns when you deviate. With that said, occasionally they get it wrong and for subsequent years you will see a new pad part number that supersedes the original. This means they really missed something and had to go back to the drawing board. Those are validated again for that particular platform.
To be clear, I’m not saying you can’t improve braking performance but there are many unknowns when trying to do so. And improving wear may reduce stopping power. Or reducing fade and minimizing uneven friction layers (that cause the pulsing) may increase dusting and wear faster. It’s a balancing act.
