What is the friction grade for the most recommended E39 brake pads (e.g., EE, FF, EF)

Originally Posted by z_driver

that doc's for three years, April 2008- April of 2011.

I couldn't find anything newer.

Originally Posted by z_driver

I suspect that's for rebranding.

I never understood brake pad rebranding.Seems to me the friction code should prevent us from being confused by the extensive use of brake Marketing rebranding but even AMEC is in cohoots with the brake marketeers.

For example, this document says the following about rebranding tests:
- AMEC Manufacturers Guide

"If the material is produced for other companies ... this information is considered to be proprietary and will not be released"

Originally Posted by z_driver

Be interesting to see what the Akebonos have imprinted 'under' their cover.

Indeed!

Originally Posted by z_driver

Maybe the law applies to pads only?

I hope not. But, we'd have to see some more shoes to be sure.

EDIT: This textbook on brake friction coefficients implies the edge code should be printed on the shoes:
- Brake Friction Theory textbook (pdf)

Brake pads and shoes have markings on the edges that give the approximate coefficient of friction at low and high temperatures.

Notice that this textbook says that you want the SAME cold & hot coefficients, which would imply that EF is not as good as EE or FF.

Well, here is a picture of the Jurid pads I replaced with Centic's. In general appearance the Jurids seem to be of higher quality and they have friction code markings that seem to correlate with pad regulations. HG in this case. Again, the Centric's had only a part code and date.

I'm surprised I did not find your Bosch edge code markings

Originally Posted by Christop55her

I'm surprised I did not find your Bosch edge code markings

Yeah, not sure what to make of that other than that particular PDF doesn't appear to be the latest version. 

My rudimentary attempt to decipher the code yeilds: (B)osch(N)orth(A)merica(Q)uietcast(1213)some proprietary formula(FF)OE equivalent friction rating.

Originally Posted by z_driver

HG in this case

Good! The document above indicated that both pads and shoes should have the edge code.

BTW, "H" is by far the highest friction grade we've seen yet!

Sorry about not finding a later PDF that might have Bosch covered.

It's nice to know this thread helped someone today on the E46 forum:
> E46 (1999 - 2006) > Brake pads need changing ...which ones to buy???

I just installed HAWK Performance Ceramic Pads.

Grade = FF

Reading suggests normal street driving doesn't rise to the occasion for FF. I think FF is the lowest track grade for racing cars. They should last a long time on street cars. I imagine track cars' brakes get much hotter than street driving. Hence the need for pads that retain their friction at higher temps.

Originally Posted by z_driver

Jurid Shoes: Well, here is a picture of the Jurid pads I replaced with Centic's. In general appearance the Jurids seem to be of higher quality and they have friction code markings that seem to correlate with pad regulations. HG in this case. Again, the Centric's had only a part code and date.

For the record, this was posted today:

Originally Posted by waehrik

I just bought a set of Wagner Quickstop Z831 shoes for $20.46

Does the friction rating tell us anything about fading?

This was posted today:

Originally Posted by senser

Akebono's FADE like crazy for me under hard driving.

Looking up the friction ratings, the recommended Akebonos have the highest shown (GG).

But does that tell us anything about fade?

Check the notes at the bottom of this document.

I've put about 70,000 miles on a set of Akebonos, and I have never noticed brake fade. My 530i has the same brakes as the 540i That said, the 530i is somewhat lighter than the 540i and I don't drive that hard.

Originally Posted by Steve530

Check the notes at the bottom of this document.

OK. So, the friction code 'is' also a fade code, of sorts:

The top clearly says:

This two letter edge code mandated by the DOT, and painted on all street legal brake pads, will give you some indication of their ability to resist fade. But only if you know how to read them. However, because of the wide range involved in each letter, it is only a rough indication.

The bottom says:

The second letter of the code represents the hot friction coefficient based on a fade and recovery test. We all should know what brake fade is. If you've ever had to use the front brake extensively and found that its effectiveness quickly diminished, that's fade. Recovery is basically the period where the brakes are gradually cooling off.

Lastly, it says a GG fades very rarely in the charts.

So, like many people, I suspect the poster is mistaken about the GG pads fading on him.