In PUBs past, Jim Villers extolled the virtues of "carbon-Kevlar" pads. When my axle swap brought the issue forward I did some internet and phone searching of 'super-duper' pads, and for various reasons -- from product to attitude -- ended up with an old-line brake outfit in CA, the Porterfield Brake Co., one of the suppliers Jim mentioned in his Drivability presentations. They make friction surfaces from the ordinary to the extreme (endurance racing, for example). The one that Jim recommended, and that I use, is their carbon-Kevlar pad rated for street and the occasional light track work. They don't need any warm-up. To me, they're not at all exotic, and as I've said somewhere here before, they just
like to stop the car: smooth, velvety and silent, too. And clean, whatever that means. That is, my car doesn't get many weekday miles, so not much mileage has mounted up in the ~ 18 months they've been on. Mine isn't -- and likely won't ever be -- Anthracite; I've just been washing the wheels along with the rest of the car and haven't noticed brake dust darkening or much of any before/after color difference during washing. [I run an unconventional military-grade clear anodized finish over lightly-blasted surfaces on pressed aluminum diesel sedan wheels with just the small ("dogdish") caps, so there's a fair amount of lightish grey area showing.] Again, you work to a higher standard, but I do appreciate not having the brake dust issues I had before.
Porterfield R4-S pads are claimed to have ~ 35 - 100% greater friction coefficient than ordinary formulations, to be rotor-friendly (definitely non-metallic) and produce much less (and 'nicer') brake dust. Nothing in my experience contradicts any of that.
During the search I came across Jerry Jones. His website,
www.formymercedes.com, sells Porterfield products at Porterfield's prices, and with an interesting twist. Ordered through him, the pads ship directly from P-field and include a little box of installation-prep goodies designed to prevent brake squeal; this seems to be space-agish stuff but the fairly extensive procedure is basically just a very thorough surface prep. This kit is included at no cost. I asked him about it and learned he'd had a few complaints regarding brake squeal years before, looked into that whole issue and decided on this course as the way he wanted to go: says he hasn't had any further problems. In my experience, following maybe 70% of the procedure has resulted in just a peep or two from my pads. ["70%"? - long story involving wrong parts, track day deadline and resulting goat-rope 500+ miles from home and then in my driveway until 3AM.] Brake squeal's been with us since before the advent of discs made it much more common; I doubt that it's significantly worse with these pads, and regard the prep kit as a nice no-cost extra. I can't say they'll 'give you 9 cents change'; maybe 6 or 7. YMMV. I do consider them to be a significant all-around upgrade.
Our old Mercedes models have dropped off from specific mention on both the Porterfield --
www.porterfield-brakes.com -- and Jone's listings, but the call-outs are still the same as ever for pads for our ATE calipers (mine is a 68/69 280SL, should be the same pieces as yours, yes?): front: AP45, and rear: AP31. The identifier for the appropriate carbon-Kevlar compound is: R4-S.
Both sources have customer service by toll-free telephone. Jones is in Buffalo Grove, IL and does the customer service all by himself; he's meticulous by nature. Porterfield is friendly and efficient with phone orders. It's possible that you can get a better price at Livermore Performance, Inc. in Livermore, CA, but that's outside my experience.
Denny