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Clare Snyder Clare Snyder is offline
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Default Need help INTERPRETING these test results police cruiser SAE J866a Chase Test

On Sun, 14 Jan 2018 23:11:16 -0000 (UTC), Mad Roger

On Sun, 14 Jan 2018 14:46:53 -0500,
Clare Snyder wrote:

In the end, I don't see any indication whatsoever that anyone here knows
how to properly compare the performance of those $157 and $20 brake pads
and shoes in order to make an intelligent buying decision.

That's kind of a sad revelation for this newsgroup, don't you think?

Not at all. Even a "brake engineer" would not be able to tell ypou
how to tell the good fromthe bad (or less good - don't knowthere is
any "bad"brakes on the market - even a lot of the "counterfeit" stuff
will stop the car).

Hi Clare,
You're actually the *only* one on any of these three newsgroups who knew
the bottom line from the start, which is that we're ****ed when we try to
compare a $157 brake pad with a $20 brake pad.

Everyone loves a number line, which is why people buy batteries by warranty
or why they say the stupid line that "you get what you pay for" when we all
know that a $300 set of speakers at Toyota gets you a crappy speaker
compared to a $50 set at Crutchfields.

So you can never tell by price. You can only tell by quality.
And there's no way to *compare* quality, it seems.

You knew that. Which is why you stick to name brands. Which is fine, as
name brands is just another way of saying you buy by a number line, where
the number line only has parts on the right and left of zero.

Brands to the right of zero you'd buy (e.g., Napa or Wagner) and brands to
the left you wouldn't buy.

But that sucks too as a determinant although at least with the DOT Edge
Code, we can tell, for sure, which company made the friction material (so
we could tell that an Axxis pad is the same as a PBR which is the same as a
Metal Masters pad, for example).

The "brake engineer" would likely beable to tell
you which of "his" product is better - but not necessarily if his was
betteror worse than another brand.

Yes. That's what the AMECA engineer basically said. He even said, many
times, that the brake engineer might not even know himself, unless he
himself submitted the pad material for testing.

So, basically EVERYONE is buying brake pads completely blind.

If that's not sad to you, it is to me.

Back when I was a Toyota tech and service manager there were at least
2 different formulationsof brake pad that fit numerous Toyota vehicles
of the time - one was used up to a particular production date, and
another after. Both were available as replacement parts, and I always
used the one, regardless of vehicle production date, because it
stopped better and I could install the second and third set without
having to replace rotors. It was a difference between the metal used
in the "semi metallic" lining. One was magnetic - the other had brass
in it.

If you have the DOT Edge Code, we could tell at least who made each
friction material, and whether they're on other pads, and whether they
truly were the same or not, and what the friction coefficients were.

But that's about it for what we could tell about the two pads from just
having them both in our hands.

That's sad.

The brass stopped better and didn't cause pitting of the
rotors. The pads didn't last as long, but virtually nobody ever
actually wore out the "magnetic" ones before the rotors needed
replacing, so the pad life, in and of itself, was a total non-issue.
IIRC the brass was the early pad and the iron was the

I don't even look at the marketing bull**** because one spec of dust and
they can call it ceramic. There's no law or rules. They can put a spec of
iron and then call it semi metallic.

The only laws are they can't put asbestos in it.

The rest is marketing bull****. We've been there, so let's not go there

We're essentially choosing brake pads almost completely blind.
And that's sad.

The same situation rose years back on, I believe, FORD brake shoes
where the linings would deteriorate and fall apart before the half
wear point. They went from rivetted to bonded, and then the glue
started letting go, and the entire lining would free-wheel between the
shoes and the drum.

Yes. I'm not covering defects in workmanship or design of the backing.
I'm just covering the friction material here, because friction is the
fundamental thing a brake pad does.

N o, the PRIMARY quality of a brake material that YOU need to worry
about is "performance"
That "performance" includes how well it stops hot and cold, brake
feel, pad life, and rotor life.

The coefficient of friction only affects ONE of those qualities - and
the gross difference between a good e and a poor g is NEGLIGIBLE .
(Both are essentially an F -)

AN OEM GUALITY brake part will be CLOSE to what was specified by the
manufacturer - may be marginally better or marginally worse - but they
will be close.

I talk to my jobber and ask what their warranty experience is with
different products. If they have noise complaints, or poor wear, on
one brand/model but not on another, I stay away from the one that has

Years ago I got and read the Service Station and Garage Management
magazine - which had articles about different products - written by
mechanics, not engineers and salemen, reporting both the Gems and the

I know all about the issues that we will never be able to compare pads with
such as longevity of the pads and rotors, fitment, noise, dusting, etc.

Brake materials are a fine line between a science and a "black art"

I agree that for the *formulator*, it's likely halfway between science and
a black art, but for the poor consumer, it's complete marketing bull****.

Look for a certified label

New vehicles must meet federal performance standards—a minimum
stopping distance in a variety of situations under a specified pedal
effort. Many consumers assume all aftermarket replacement pads will
perform just as well or better than factory parts, but that's not
necessarily the case.

In an effort to improve the customer's comfort level—and also to avoid
future government regulations—brake manufacturers can test and verify
their products under two voluntary certification standards. Both are
designed to ensure that replacement brakes are as effective as
original equipment, and consumers should make sure that any pads being
installed on their vehicle are certified.

The first is an independent proprietary program developed by Greening
Testing Laboratories in Detroit called D3EA—which stands for Dual
Dynamometer Differential Effectiveness Analysis. This procedure tests
front and rear friction materials together on dual dynamometers, then
simulates vehicle weight and speed through a computer program to
measure braking effectiveness and balance for different applications.
D3EA was introduced in 1996, and among the first aftermarket companies
to achieve D3EA certification were ACDelco, NAPA, Raybestos, and

The Brake Manufacturers Council (BMC) has a second certification
standard called BEEP, or Brake Effectiveness Evaluation Procedure.
BEEP testing is conducted on a single dynamometer, and the numbers are
washed through a computer program to compare brake performance with
federal standards for new vehicles. The BEEP approval seals appear on
packaging as manufacturers submit products for certification.

The D3EA tests are proprietary and more expensive, but they're also
completely independent and tougher to pass. Brake manufacturers have
contended that most consumers change only the front or rear brakes at
one time, so a concurrent dual test is unnecessary. But, according to
officials from Greening, NHTSA tests in the 1980s concluded there was
a significant reduction in braking performance when there was a
differential between front and rear replacement pads as compared with
original factory parts. That report provided some of the motivation
for the brake industry to begin seeking a certification standard
before the federal government issued regulations for replacement pads.
The obvious concern over BEEP testing is that the manufacturers
themselves oversaw the development of the certification standards.
While the program received input from the Society of Automotive
Engineers and actual certification is currently conducted at an
independent laboratory, BMC members can conduct similar tests on their
own single dynamometers and compute the numbers.

Consumers must remember that not all of an aftermarket manufacturer's
lineup gets certified, only pads designed for a specific vehicle that
passed the designated test. Also, since the D3EA tests are expensive,
manufacturers may test just the standard line for a particular
vehicle. One can assume then that any upgraded line from that same
manufacturer will meet the test standards. That's why heavy duty or
the new ceramic pads may not carry the seal. The best advice is to
look for manufacturers that aggressively test their standard line,
then move up in grade if you need more performance or seek other
advantages such as minimal wheel dust.

Nobody, it appears, actually knows anything about buying brake pads when
they have two pads they've never seen before in their hands.

You have the EXPERIENCE to pick a pad, but even if I shoved two pads that
you have never seen before (such as two I'm going to need to compare), you
can't compare them either (unless you know the brand).

Even then, you harp on the conterfeits, so unless you know a telltale sign,
you can't tell from the brand either, especially when buying online.

Which is why I seldom buy stuff like that online - and if I do, I buy
from a vendor I KNOW is honest and reliable. (I'll sometimes order
parts from Napa Onlineand pick them ujp at my local napa store -
particularly if I find I need something on the weekend when the store
is not open and I want it for Monday)

SO it's just sad, sad, sad, that we're all utterly blind when it comes to
comparing brake pads. I think that's very depressing. We're at the mercy of
marketing bull****ters and idiots who do brake pad reviews on amazon that
make no sense and aren't for the same car and compare things like worn old
pads against brand new pads, and the butt dyno takes over from there.

Then pay the extra and buy the Toyota parts - that way YOU KNOW what
you are buying. Sometimes peace of mind costs a few bucks.

All those reviews are basically worthless.
All the marketing bull**** is basically worthless.

Any review by DIY guys on places liike Amazon are generally worse
than useless.

The one dream I had was that this AMECA Edge Code could tell me a lot, and
it does tell me three things, but that's it.

Sigh. It's just sad.

Buy D3EA certified parts and you stand a much higher than normal
chance of getting what you need.

I do thank you for your help, as you're the only one, I think, who knew
what he was talking about from the start. I had to learn it. You already
knew it.