On 07/30/2020 03:36 PM, Arlen Holder wrote:
> On Thu, 30 Jul 2020 11:43:59 -0700, The Real Bev wrote:
>
>> I seem to remember 40K on the fronts and 80K on the rears.
>
> Hi The Real Bev,
>
> Thanks for that information about the front pads, which is what I seek.
> o Personally, I get about one thousand miles per millimeter of pad

That's a memory from long ago. I don't actually KNOW if those are good
numbers.

> The goal is to get those who have done the calculation to help out with an
> estimate of the number of miles per (whatever) thickness of pad, on
> average, that others would get (as I drive on mountainous roads a lot).
>
> People either know how many miles they get, or they don't know it.
> o So I thank you for that datapoint of another average'ish driver,
>
> If you get 40K per pad, and if new pads are, oh, hmmmm... how thick?
> <https://i.postimg.cc/4NzSKGFr/pads05.jpg>
>
> I happen to have a few sets of "Centric Premium Ceramic" pads lying around,
> P/N 301.09080, marked "CEN30109080 31AC9101 GG 02 B19" (i.e., cold/hot
> friction rating of G/G, which is a friction coefficient of 0.45-0.55)
> <http://www.napbrake.com/2018/02/24/friction-coefficient-brake-pads/>
>
> The backing plate is 6mm & the pad, brand new, is an additional 12mm:
> <https://i.postimg.cc/DwnYLN9m/pads06.jpg>
>
> At 40K miles, that's about 40,000miles/12mm = about 3K miles per pad mm.
>
> Given the worn pads are about as thick as the backing plate, that's:
> o 6mm times about 3K miles/mm = about 18,000 miles left on those pads
>
>> Don't they put those little metal squeakers on the pads any more? You
>> can tolerate the squeaking for a long time, the grinding for a shorter
>> time, and the hogging in for only a VERY short time. Don't ask me how I
>> know this.
>
> This is what they come with, apparently:
> <https://i.postimg.cc/4NzSKGFr/pads05.jpg>

That looks too complex. I seem to remember (from the 1983 Sentra) just
a little thin metal tab that stuck out and contacted the rotor at a
chosen point. I bent it more to give me more wear, but I sent the car
to the knackers long before that point.

> Regarding not asking how you know this, I know that steel on steel has
> almost the same cold/hot friction coefficient as many brake pads people buy
> (e.g., EE pads) where I've seen rotors worn down to the ribs and the brakes
> "still work".

That would be me. The rotors looked like a beginning lathe project --
proof that they're made of softer stuff than the pad's backing plate
nubs. I could feel and hear the grinding, but the braking was just as
good as before it started. When I had to brake carefully to avoid
hogging in I figured I needed to deal with the problem. At the time the
rotors (Pep Boys, used) cost only $10 each. The cost wasn't the
problem, just the time.

> You get three times the miles I get, where I get around one thousand miles
> per millimeter of pad, or thereabouts, on my bimmer (OEM Textar/Jurid pads,
> with cold/hot friction ratings of F/F), looking at my records, but I live
> in hilly country, where people would likely get more on flat land.
>
> If we don't get further data, an average of two thousand miles per
> millimeter might be our starting point, in which case that's about twelve
> thousand miles left on those worn pads.

I wouldn't let it go that long now. I love my little Corolla and don't
want to hurt it. Rear drums, but I've never noticed a problem with
insufficient brake power from the rear. OTOH, how would I know?

--
Cheers,
Bev
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ^^^^^^^^^^^^
"Friends help you move. *Real* friends help you move bodies."
--A. Walker