Brake pads revisited

[Gary B.]

Re: Brake pads revisited

Joe,

Yup. I just figured out that to get organic, one has to get the AC Delco 14D8 Advantage series. The AC Delco 17D8 series is the Professional series, which as we now know are described as "ceramic" on the box, although many websites and e-bay sellers claim them to be organic.

Gary

[Joe L.]

Re: Brake pads revisited

Joe,

Yup. I just figured out that to get organic, one has to get the AC Delco 14D8 Advantage series. The AC Delco 17D8 series is the Professional series, which as we now know are described as "ceramic" on the box, although many websites and e-bay sellers claim them to be organic.

Gary

Gary------


AC Delco still says the 17D8 are organic but their "specs" have apparently not caught up with reality.

[Gary S.]

Re: Brake pads revisited

And now, to add to the confusion, I thought I was getting organic not ceramic. I will let you know what comes in. After all this work, to get the wrong product would be very disappointing. Even reading the description of the 14d8 (as well as the 17d8), they state "Ceramic, Semi-Metallic, and Organic formulas provide safety and reliability for a range of vehicle applications".
Talk about confusion.

Added:
And, to add to the confusion, here's a link to ACDelco:
http://www.acdelco.com/auto-parts/brakes/advantage-organic-brake-pads.html. their site has the same sentence as amazon.com and they also say that these are organic. The description here and elsewhere seem to toss around "organic" fairly loosely.

[Gary B.]

Re: Brake pads revisited

Gary,

I think the phrase "Ceramic, Semi-Metallic, and Organic formulas provide safety and reliability for a range of vehicle applications" is simply talking about the range of AC Delco brake pad products they sell. I think it you got the 17D8 pads, they will be ceramic. I just ordered one set of 14D8 pads, which I'm hoping do not say ceramic on the box.

Gary

[Gary S.]

Re: Brake pads revisited

Gary B,
I agree that phrase must be a marketing "one size fits all" statement concerning pads. Looks like my 17D8 pads are going back and I'll order real organic 14D8 pads.

[Gary R.]

Re: Brake pads revisited

The pads I got from Canada do not say ceramic so I am thinking they are organic and maybe old stock? Really don't know. I returned the ceramic Mexican pads on Monday, got the credit today. I'll wait till you guys get in the 14D8's to see, maybe I'll order a set of those. Glad I wasn't in a hurry for them.

[Timothy B.]

Re: Brake pads revisited

I hope you guys don't throw rocks at me but what's the matter with ceramic pads.

[Joe L.]

Re: Brake pads revisited

I hope you guys don't throw rocks at me but what's the matter with ceramic pads.

Timothy------

Actually, I like ceramic disc brake pads. However, the major downside is that they are harder on rotors. Personally, on my 1969 I'd only use organic pads. But, for other cars I have, I'd use ceramic.

My Grand Prix has always had OEM ceramic pads. They work great. However, at 100,000 miles the front rotors were worn beyond re-use. My 1969 Corvette which has always used OEM organic pads still has the original rotors at 200,000 miles.

[Gary B.]

Re: Brake pads revisited

Gary,

I'm supposed to have a set of 14D8 pads delivered on Friday and I'll let you know what the box says about composition.

Gary

[Duke W.]

Re: Brake pads revisited

I think some of you should reconsider your opinions about "organic" versus "ceramic". You can research as deep as you want, but I'll try to get you started.

Back in the day asbestos-based friction materials were best for nearly all road cars, and when it was banned in the seventies, friction material manufacturers scrambled to come up with satisfactory replacement materials. Metallic (say at least 50 percent ferrous material by mass), provided very good fade-free performance, but the Cf varied quite a bit with material temperature, plus they were dusty, noisy, and hard on rotors- just like the metallic shoe option on drum brake Corvettes.

It took some time, but friction material manufactures (and there are currently only a handful worldwide) eventually developed new non-asbestos organic (NAO) materials that, for the most part, duplicated the characteristics of asbestos-based materials, and these materials have some pretty strange components like plant fibers derived from peanut, and coconut shells, glass, rubber.... Friction material, like tire rubber compounding is a "black art", and manufacturers consider their witches brews to be very proprietary. Even OEMs usually don't know the material details. They send RFPs to friction material manufactures with specs and then the friction material manufactures submit examples for testing.

Ceramic-based materials were developed in the eighties and are usually considered "premium" because they are higher cost. These also have low metal content, but, for example, the PBR Deluxe pads I installed on the Mercedes have copper filaments embedded in the material between the surface of the pad and backing plates. These aid in heat transfer since most ceramics are thermal insulators, but since copper is soft, it doesn't chew up the cast iron rotors. (Cast iron is a very tough, wear resistance material.)

Given that the C2 brake system is so overdesigned (even by today's standards) there is absolutely no need for metallic materials unless you are doing some serious road racing.

My choice for normal road driving, even if very aggressive and up to including "light racing" would be ceramic because of the relatively constant Cf including up to high temperatures where NAO materials would fall off significantly, low noise, low (and light colored hard to see) dust, and high longevity with minimal rotor wear. At our ages and annual mileage accumulation on vintage Corvettes we will likely never have to replace the pads again.

Another advantage of ceramic is that the materials won't change even if severely overheated. Very high temperature can damage organic materials, which in some cases may render the friction material ineffective and require replacement to restore normal brake performance.

Just make sure they are rated at least FF, especially on cars with no vacuum booster. G would be even better for non-power disk brakes, but might be tough to find. The current PBR Deluxe Plus I have on the front of my MBZ is FG, but I have never run across a friction.material labeled GG.

Higher up in this thread Joe L posted photos of original OE organic D8 pads that are rated FE. Gary R's recent replacements are FF, so they have greater high temperature fad resistance, and my bet is that they are ceramic.

Duke

[Gary S.]

Re: Brake pads revisited

I have used ceramic exclusively on my BMW X5 and previously on my BMW 328xi (since sold) and will be putting them on my wife's Lexus RX. I like the low dust feature but I also know that rotors are cheap whereas my 1972 Corvette stills wears its original rotors, riveted in place. I hope to keep them on for a lot longer.

[Duke W.]

Re: Brake pads revisited

Back in the day I knew a lot of people who had late eighties, early nineties Mercs and some only got 15K miles out of the OE front pads. In addition dealers often also installed new rotors, and they were certainly needed after the second set of OE pads wore out.

I changed the OE pads on my 190 at 15K miles due to all the dust and squeal even though they were not worn out with Repco (PBR) Deluxe. Based on measurements over the years I estimated their life at 90K miles (105 on the odo), but changed them a couple of years ago at 82K miles during a brake fluid flush with a spare set I had in inventory... just wanted to get it done since I knew it was the last pad change I'd ever have to make. Even given the few hundred miles of track events (with the Repcos) the OE rotors are will above minimum.

My Cosworth Vega is another case in point. Before ever doing a track event I replaced the solid front rotors with Monza vented rotors and companion larger calipers. They came off a low mileage junk yard car, but just to be sure I turned them down ten on each side to 0.860" to be sure they were straight. Several tens of thousands of street miles, 5000 miles at Riverside and Willow Springs, and six sets of OE replacement Delco semi-metallic pads later they are 0.830, which is still comfortably above the 0.815" minimum, and since I haven't raced it for 15 years and have no intent of ever doing so again, I'm not worried about it.

Since all my cars have been on road racing tracks, all the rotors are scored silly. Most brake shops would say they are junk just by looking, but that's not true. They are straight, above minimum thickness, and perfectly serviceable. The only issue is that new pads require a thoughtful break-in for at least 200-300 miles of normal road driving before they achieve full effectiveness. Most brake shops will turn or replace rotors apriori because their customers would complain that the brakes were no good, and you can't expect the average driver to go though a concerted break in procedure.

Don't let some brake shop do this to you!

I also conclude that rotor wear with ceramic pads is no more than with NAO, but the ceramics will last twice as long.

The OE Mercedes pads worked great but had poor secondary characteristics that made them a poor choice for American driving conditions. I expect US models were equipped with the same pads as European models where the brakes were required to bring the car down repeatedly from triple digit to double digit speeds on the autobahn.


Duke

[Gary S.]

Re: Brake pads revisited

My 17D8 pads came yesterday and went back today. The website says "organic" and the box says non-ferrous ceramic. Closer reading on the web site and it has the AC Delco phrase verbatim

• Ceramic, semi-metallic, and organic formulas provide safety and reliability for a range of vehicle applications.

Gary B.,
Please let me know what your pads are when they come in. I have found 14D8s at Rock Auto and Amazon but the hilarious thing is that the Amazon site says "ships in 2 to 5 weeks". Rock Auto is 3 days.

Gary S

[Leif A.]

Re: Brake pads revisited

As promised in an earlier post, here are pics of the AC Delco 17D8 pads I ordered/received from Rock Auto. After further research and reading Duke's #55 post above, I'm going to give these bad boys a try.

[Gary S.]

Re: Brake pads revisited

Leif,
That is exactly what I received and just sent back today. I am sure that they will work well (see Duke's response) but if you are looking for organic, those are not it.