I've been using the Raybestos EHT pads since 2015 on my cars and the numerous other cars I maintain (adult kids', friends', etc.). I switched to them based on the "hybid" nature of the pads, hoping to address a problem that I was seeng on all of these cars since I switched to ceramics from semi-metallics. It seems I was going through rotors a lot more than I should due to the back side (piston side) deteriorating. The braking surface gradually became a thin band more or less in the center, with a thick and irregular transfer layer, and a lot of corrosion and rust-jacking. The outer side of the rotors weren't anywhere near as bad, but still had a somewhat splotchy surface appearance. This was happening on my Mazda 3, Dodge Caravan, Toyota Camry and Corolla, Ford Escape, etc. Rear brakes seemed to have the problem even worse than the fronts. I suffer the corrosive winters in a northern salt-belt climate, which may factor in somehow.
I was using name-brand pads and rotors, frequently Raybestos Quiet Stop and Advanced Technology, Brembo, Centric, Axxis, and Wagner. I don't recall exactly which parts/combinations exhibited the problem most, but it was very frequent and consistent. I also had the problem on OEM rotors, but since I buy my cars used, and don't buy OEM brake parts, that's limited experience. I keep my calipers in very good condition, thoroughly cleaning and lubing all active surfaces, slide pins, etc. every time I replaced pads, and quite often between pad changes if I have the calipers off for other work. I was NOT having problems with slides binding - the caliper and brackets were freely moving. I flush brake fluid very often, and rebuild or replace calipers at this slightest hint of a problem (e.g. torn boots, grooved bracket pad support surfaces). I pay attention to rotor runout, always listening for rubbing, and frequently measuring and indexing the rotors to minimize runout. For a while I tried swapping the ceramic pads for semi-mets for a few hundred or thousand miles, before the rotors got too ugly, then put the ceramics back in. That helped clean up the rotors for a while, but didn't stop the problem from recurring when running ceramics again. I drive fairly aggressively, so use the brakes hard and often, as does my wife.
I was using a lot of the Raybestos parts when a lot of this was going on, and was about to abandon Raybestos and try something else. My Mazda 3 got new rotors and reman calipers at the last pad change. I forget what pads I installed (that particular order in my RockAuto order history doesn't display), but I was usually using Raybestos Quiet Stop and Advanced Technology around that time). Later that year (probably >5K but
After a few hundred miles on the semi-mets the rotors looked good. I lightly sanded the rotors by hand with garnet sandpaper, washed with soap and water, then installed the new EHTs.
Result - From my experience so far, this has completely solved my problem. I haven't seen any evidence of the back-side deterioration, throughout the life of the pad, or to date on my second set. So far, same for the sets I installed on the Caravan, Ford Escape, or Subaru Outback. I like their performance characteristics, primarily because I just don't think about my brakes anymore - they stop nicely, never faded, I don't notice any difference when wet or cold (down to -20degF anyway). Some brake dust is there, but no more than anything else I've tried, not real dark, and relatively easy to clean. I only have any squeal at all, and that's infrequent, on one car, in reverse, in the morning. (Regarding squeal, other than that, I haven't had ANY other car with brake squeal since switching to ceramics and paying attention to installation practices.) However, I standing outside the car or with the windows open and at slow speed, the EHTs make a bit more noise when working than the other pure ceramics I used. It's not high-pitched or irritating at all (especially since I just imagine the noise scraping the rotors clean!) I don't yet have enough experience with these to comment on rotor wear - looking at them I get the sense that they are wearing a bit more and perhaps grooving a bit more, though I haven't seen much of a ridge at the edges of the wear surface. I don't see a distinct transfer layer like I could with the regular "pure" ceramic pads. Even if it eats the rotors a bit more, my rotor lifetime will definitely increase since I'm not throwing them away prematurely due to the back-side damage.
So as far as I'm concerned, I'm sticking with them for the foreseeable future. Maybe someday someone will come up with something better, but for now I'm perfectly happy.
But I'm still curious why I haven't seen anyone else commenting on this issue. I was initally thinking that I was focusing too much on pads and not enough on rotors, but since these pads seem to be working well with my old/similar rotors, I'm not sure the rotors are the issue. Has anyone else experienced the back-side corrosion as regularly as I have? And has anyone who has seen this problem tried the EHTs and had it resolved with the EHT's (or not)? Any other ideas?
