What's the tale of ceramic brakes?

I'm not familiar with ceramic brakes, but they come with a lifetime warranty.
Are they really that good? Do they threaten any other brake system
components? Do they really last forever? Any informed comments appreciated.
Reply to
briang
Ready to be shocked?
What do brake pads do? o HINT: friction, right?
*So what's the friction coefficient (cold/hot) of those brake pads?*
Xeno and others know more than I do, but I've researched how to choose automotive brake friction materials, even down to calling the PBR and Metalmaster & Axxis (all the same company!) and Centric and Zimmermann, etc., marketing guys.
What they told me will shock you, but when I tell it to you, you have to sit back and have an "Aha" moment, because the sad truth is that the claims on consumer focused automotive braking friction materials is far more marketing than truth.
An example of the cold hard unabashed truth? o The word "Ceramic" in friction materials is nearly meaningless.
The Axxis and Centric marketing guys told me they can sprinkle a bit of pixie dust into the mix, and "Voila!", it's ceramic!
And, the warranty is a marketing gimmick also.
Just like with consumer automotive batteries and automotive tires: o The warranty does not track performance (it tracks price better).
The good news is every single brake pad sold in the US for passenger use has a code stamped on the side which tells you the cold and hot tested friction rating. Every single one. o EE === about the same friction coefficient as steel on steel o FF, GG, HH, etc.
Now, you'd "think" that friction rating equates to stopping distance, but it's not _that_ simple either. Sigh.
We have a looooong thread on this somewhere, which we can dig up for you: o
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Reply to
Arlen Holder
The big thing with them is that the materials used don't leave the ugly rust colored crap on the rims. If your vehicle came with them, keep using them.
They do tend to wear longer, however much of that depends on how you use the brakes. Constant stop and go gets you increased wear. They don't last forever, but I have seen sets with 60K on them that still had a lot of pad left.
Reply to
Steve W.
Let's think about that dust for a moment, taking into account that all pads dust and all rotors dust (where does all that worn material go anyway?).
I, personally, do _not_ have the answers: I only have questions.
There's a lot of discussion "what" that "rust colored crap" is, particularly on the bimmer forums where the OE Jurid/Textar pads dust like hell, and therefore they're often replaced by ATE or Akebono pads which seem to dust far less.
All pads dust, so one argument is that the dust is simply the "coloring" pigments in the pads themselves; but the friction material marketing folks tell me that "rust" color is a clue; it's the metal of the rotors doing the dusting.
While we'd all agree that both pads and rotors wear, so the "dust" is going "somewhere", nobody really seems to know for sure "what" causes some pads to dust more than others, given the same rotors (usually Brembo).
Reply to
Arlen Holder
Pretty much all pads have some "ceramic" elements in them. The ones that are advertised as "ceramic" are usually low dust and relatively noisy.
They don't have to last forever, they only have to last long enough for you to lose the paperwork that came with them. They don't last any longer than any other brakes on the whole. But the manufacturers have worked out that most people won't save the paperwork or for some other reason will never take them up on the warranty when they fail.
If you want long-lasting brakes, ask taxicab owners what they use. --scott
Reply to
Scott Dorsey
The brake dust is simply the mix of pad debris and iron from the rotors. Semi- metallic pads are just that, iron and other metal powders mixed into the various resins and binders that make up the pad. Go visit a salvage yard and look at brakes that have been setting unused for a while, you can see them rotting apart and crumbling. That is because of the heat they generate while in use baking the moisture in and on them away so they don't corrode in use.
Reply to
Steve W.
WARNING: Everything I say below is "IMHO" as an overall disclaimer since I am _not_ a brake friction coefficient mechanical engineer.
My "wisdom" on warranties is that anyone who compares by warranty... o Is simply proving they know absolutely nothing about the product.
I think warrantee's, IMHO, are for people who don't understand the product. o People _desperately_ desire (a) good, (b) better, and (c) best
Everyone wants a number line to compare good, better, & best. o MARKETING is perfectly happy to give people a false numberline.
Rather than compare the product on actual performance metrics... o Marketing tricks them into comparing (meaningless) warranties.
MARKETING is _happy_ to give people a "linear" way to compare product o By warranty, they can even have you compare to the competitor's warranty!
All without even once looking at what makes the product work o For example, without looking at the friction coefficient for brake pads
The point is warranty has _nothing_ whatsoever to do with the product. o There is only one time, and one time only when you care about warranty. (And that's when you _know_ you're gonna abuse the product.) Otherwise, the warranty is worthless except under the tie-breaker rule. o If two products are EXACTLY alike in all other things... Then, and only then, does the warranty many _any_ difference whatsoever.
I've concluded, long ago, that these so called warranties, are (mostly) worthless for a variety of reasons, one of which you touched upon o First, is that the warranty has _nothing_ to do with performance o Second is, as you noted, you often need to have pristine paperwork o Another is you generally have to be the original owner (why?) o Another is they generally pro rate where it's not always linear o Worse, they often don't give you any sales price when they pro rate o And, you (often) have to buy the _same_ item (Wait a minute ... isn't that the items that failed prematurely?)
Clare Snyder brought up the "fleet report" from the Michigan Police Department, who tested brake pads for the fleet vehicles (which taxis are also). o Need help INTERPRETING these test results police cruiser SAE J866a Chase Test
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There is only one thing, and one thing only, that is _reliable_ that a consumer can go by, which is the friction coefficient (e.g., I'd never buy less than an FF and I'd prefer a G or an H in most cases).
Everything else that is printed on the box is, IMHO, worthless marketing. o If you _must_ have a good, better, best, "most" people might recommend: a) good === non asbestos organic b) better === semi metallic (or ceramic?) c) best === ceramic (or semi metallic)
But that's all marketing BS since they can sprinkle pixie dust and call it anything they want to call it. I've spend more than a few hours on this topic with the marketing guys, mostly at Axxis/PBR/Metalmaster & Centric.
The _only_ guy who knows _anything_ about the brake pad is the guy who certified it for the DOT and who therefore gave them the FF, GG, HH, whatever friction code (plus a few other things about the material).
The rest of us have _nothing_ to go on other than boy-racer bullshit reviews (almost all of which are never on the car you own, driven on the roads you drive, and driven the way you drive it).
In the end, all you have are two things, and two things only: 1. The friction coefficient, and, 2. Your personal experience (if you've used those brake pads on that car)
Reply to
Arlen Holder
Hi Steve W., I'm not gonna disagree since what else _can_ it be? o Brake dust o Iron dust
Yes. And no. o They can sprinkle a bit of metallic pixie dust & call is semi-metallic.
What matters is stuff that you can measure - and stuff you can't measure. o The friction coefficient you can measure 'cuz it's printed on the pad
Everything else you can't measure even though they're still important: a. noise b. feel c. wear
It's sad, but the _only_ thing that is "reliable" about choosing brake pads is the friction coefficient printed on the pad itself.
Everything else is subject to marketing bullshit, such as the warranty.
I'd love to read a scientific paper about what causes all that dark dust.
I'm on a lot of car forums where the one thing I've never been able to ascertain is why don't _all_ pads cause the dark dust, given that we don't use stainless steel rotors in normal automotive use.
So the iron from the rotor should _always_ be there, even if the brake pads dust with different coloring (the lighter the better of course).
Clearly, my bimmer dusts like crazy with the FF Textar pads, less so with the FF Jurid, but even less so with the FF Akebono or FF PBR pads.
Why?
I've never been able to figure out why, given the rotors are Brembo in all cases, and they're not stainless steel rotors.
Reply to
Arlen Holder
in news:r3rf3t$t17$ snipped-for-privacy@news.mixmin.net:
EXcept the brake coefficient is not a straight item either, you can have brake pads with great coefficient but short life, or almost the same coefficient but much longer life, because of the materials they are made of, so your idea is not quite correct. material compisition is VERY important to the consideration. not just the coefficient specs. KB
Reply to
Kevin Bottorff
Hi Keven Bottorff,
I _agree_ with you fully & completely.
For example, as we covered long ago on this newsgroup, fleet vehicle EE pads seem to outperform FF pads in this police cruiser study done in 2000! o
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So even these reliable hot/cold friction coefficients aren't much to go by. o AMECA Compliance List of Automotive Safety Devices: Friction Material Edge Codes(TM), May 2011
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*But it's all we got, unfortunately.*
IMHO... everyone desperately wants a good/better/best number line! o But that good/better/best number line just doesn't exist for brake pads.
:(
No doubt material composition is critical to _everything_, e.g., o noise o dusting o wear o fade o vibration o friction etc.
The problem is that the _only_ thing we have to go on that is _reliable_ is the friction code, and our own personal experience (which isn't much if the brake pad isn't one we've _already_ tested in that exact vehicle driven under the exact conductions by the exact same driver, etc.).
My main point is that we don't have much to go by for choosing pads o Going by marketing claims is foolhardy in my humble opinion o So is going by warranty (what does that have to do with performance?) o Also is "trying" to go by "boy racer reviews" (most are worthless, IMHO)
Unfortunately, since Marketing can claim "ceramic" simply by sprinkling a meaningless bit of clay into the mix, even the age-old distinctions are "nearly" worthless, IMHO: o non-asbestos organic o semi-metallic o metalic o ceramic etc.
All we have are the friction coefficients that we can at least rely upon.
All is not lost though, since I'm of the opinion that _all_ brake pads will work fine, where, what I do, for any given make & model, is read the forums on that make & model.
For example, a _lot_ of the bimmer guys went for the Duralast battery when it was available from Autozone instead of the BMW battery, as just one example. It was the de-facto battery to use by almost all accounts.
Same with friction materials, where the old time E39 folks go for PBR over the OE Jurid/Textar pads, for example, on plain steel Brembo rotors, where only the "boy racers" are the ones who suggest the "fancy" stuff on the even fancier bling drilled and slotted rotors - and then - they claim that their braking improved fantastically.
In summary, I agree with all sensible claims above, where the OP asked about warranties, and where my advice to the OP is simple: 1. Find out what the OE pads are (brand & friction rating) 2. Buy nothing _less_ than that friction rating. 3. At the cheapest price you can get them for.
That's _my_ advice, where I've _studied_ this problem set for decades. DISCLAIMER: I'm not a mechanical engineer so take my advice with NaCl.
Reply to
Arlen Holder
Pep Boys seems to recognize their own lifetime parts. I needed an alternator for my used car and was surprised when they told me it would be free because my core was one of their lifetime alternators. I also got free brake pads. It really gripes me that I drove my Sentra to the knackers (Kalifornia Kash for Klunkers) with a LOT of lifetime parts.
Reply to
The Real Bev
I suspect you have an "account" with Pep Boys, which is how they knew what you had purchased...
Even so, does Pep Boys consider brake pads lifetime parts?
Reply to
Arlen Holder
No, this was the alternator from a used car. They had no way of knowing who had bought the thing unless it had a serial number (in which case it wouldn't have been me), but the guy didn't look it up -- he just recognized it by sight.
They used to consider ALL their parts as lifetime parts. Given that brake pads are pretty cheap and last at least 40K miles, it's probably good business to include even consumable parts.
I've always liked Pep Boys. They uses to claim 'coast to coast' because they had stores in California and ONE store somewhere on the east coast -- maybe New York. I think they have more now.
Remember when everybody sold 'lifetime' batteries? Some time in the 70s. We bought one for our 55 Chevy and one for our 68 van from Penney's. We still have the van, and we've replaced the battery twice, but it's kind of a bitch. Penney's sold all its automotive stuff to Firestone before the first replacement. We had to take our paperwork in to Penney's customer service to get an authorization to Firestone to replace the battery for free. CS people had no clue about this, manager had to be called...
Firestone guys then tried to convince us that it would be better to exchange our cheap 'lifetime' battery for one of their new super-duper 3-year batteries. Nope. Also demanded that we bring in the van so they could check out the charging system. Nope -- "Show us that requirement in the warranty..." One wanted to take our paperwork into the next room to copy it. Nope.
We haven't driven the van for a long time, but I still have the paperwork and Firestone is still in business...
Reply to
The Real Bev
I know what you mean about being in business for "lifetime warranties".
I have a Sears "lifetime warranty" ratchet hand tool which I want to replace but I can't seem to find a nearby Sears anymore.
Sears is "still in business" but not apparently in the Silicon Valley.
Reply to
Arlen Holder
Stanley Tools purchased the Craftsman line. Craftsman brand warranties are honored at Lowes and most Ace Hardware stores.
Reply to
Heron
What about K-Mart or Orchard Supply? Both deal in Craftsman.
You can get free 'rebuild kits' for their ratchets. Maybe they'd even mail you one if you asked.
Reply to
The Real Bev
Never heard of Wright, but Proto make the most beautiful tools ever. I especially like the handles on the tiny electronic pliers -- they're spread wide at the hinge (node? joint?) so you don't pinch your hand.
Reply to
The Real Bev
That's nice!
I have huge XXL-gloved hands where the strangely delicate "web" between thumb and index finger always gets pinched by my Sears small needlenose pliers!
Sometimes, when working in tight spaces on automotive engines, I wish I had those tiny Japanese hands that made the parts in the first place. :)
Reply to
Arlen Holder
Thank you both for reminding me that "other" outfits replace Craftsman handtools, where I had forgotten that I tried Orchard Supply Hardware (aka OSH) here in the Silicon Valley (who was also purchased by Sears at one point).
The problem with OSH was that they would only replace that _exact_ item with an _exact_ replacement, down to the exact model number.
If they didn't have that _exact_ item and, invariably they did not since they carried very little inventory, it was worthless.
I did NOT know about Lowes or Ace taking up the warranty, but if the problem is the same, that it must be exact, then it's worthless since you'll _never_ find the exact model number ever.
Certainly it's just a plain old six-inch 3/8"s ratchet; but everything depends on whether they'll replace with 'something similar' or not.
As for quality ... I loved the Craftsman quality so that's something I'll have to look at when/if I find a replacement (actually a rebuild kit would do me perfectly).
I'll check out Lowes/Ace where what matters is... a. Must they have the exact part number in stock to replace it? b. Will they replace with something similar of similar quality? c. Will they provide a rebuild kit instead (which is preferred)?
The great thing with Craftsman tools is they work great for automotive repair since they're lifetime quality, even as some of the "moving parts" tools (like ratchets) break over time.
Reply to
Arlen Holder

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