A Cars forum. AutoBanter

If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

Go Back   Home » AutoBanter forum » Auto newsgroups » Technology
Site Map Home Register Authors List Search Today's Posts Mark Forums Read Web Partners

What metric do you use to estimate remaining brake pad life on a typical economy sedan?



 
 
Thread Tools Display Modes
  #11  
Old July 31st 20, 08:22 PM posted to rec.autos.tech,ca.driving,alt.home.repair
Arlen Holder[_5_]
external usenet poster
 
Posts: 14
Default What metric do you use to estimate remaining brake pad life on a typical economy sedan?

On Fri, 31 Jul 2020 11:50:43 -0700, The Real Bev wrote:

> 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.


Hi The Real Bev,

I've worn _plenty_ of pads down to the rotors, where the grooving limit on
rotors is huge when you can find the spec. The limit that most people check
is the thickness, which, depending on factors, is usually two sets of pads
in my experience (but I sometimes get three sets of pads out of a rotor).

It's interesting that the cold/hot friction rating for steel on steel is
very similar to E/E pads, which I find a lot of people buy who don't know
anything about brake pads but what the MARKETING people tout (e.g.,
"ceramic" on the package could mean no more than a few spec of clay dust,
based on my personal talks with the Axxis marketing team).

Basically, the only valid data you have is what's printed, by law, on all
US pads sold for passenger vehicles, which is the cold/hot friction rating.
<http://faculty.ccbcmd.edu/~smacadof/DOTPadCodes.htm>

Anything else, IMHO, is marketing bull****.

> 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?


Drums are different, and more of a pita, IMHO, than disc brakes.
o The drums have an inspection port, but I always found it rather useless.

While you "can" hurt a caliper by metal on metal heating up things, going
to the point of a millimeter or two of that is safe, as far as I know.

In my situation of mountainous driving causing inboard wear on the front
tires, I rotate the wheels every few months anyway, so for disc brakes, I
inspect them at every rotation.

That's where the calculation of miles remaining can be of use.
o Given current data, something around 4K miles per millimeter seems ok.

That means I'll tell her she has likely at least 20K miles to go.
--
Usenet is a great public helpdesk to get ideas from a bunch of nice people.
Ads
  #12  
Old July 31st 20, 10:03 PM posted to rec.autos.tech,ca.driving,alt.home.repair
Vic Smith
external usenet poster
 
Posts: 952
Default What metric do you use to estimate remaining brake pad life on a typical economy sedan?

On Fri, 31 Jul 2020 11:50:43 -0700, The Real Bev > wrote:


>
>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?


You probably wouldn't unless your front pads were wearing fast.
The self-adjusters on rear drums are usually the weak point.
Some adjust when you brake in reverse gear, others when you use the E-brake.
Since I never (or seldom) use the E-brake here in the flatlands, my back shoes weren't even
applying on one car I had. Wondered why my front pads were wearing out so fast.
As I recall there was no mention of using the E-brake to adjust the rear shoes in the
owners manual.
  #13  
Old July 31st 20, 10:56 PM posted to rec.autos.tech,ca.driving,alt.home.repair
The Real Bev[_5_]
external usenet poster
 
Posts: 553
Default What metric do you use to estimate remaining brake pad life on atypical economy sedan?

On 07/31/2020 02:03 PM, Vic Smith wrote:
> On Fri, 31 Jul 2020 11:50:43 -0700, The Real Bev > wrote:
>>
>>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?

>
> You probably wouldn't unless your front pads were wearing fast.
> The self-adjusters on rear drums are usually the weak point.
> Some adjust when you brake in reverse gear, others when you use the E-brake.
> Since I never (or seldom) use the E-brake here in the flatlands, my back shoes weren't even
> applying on one car I had. Wondered why my front pads were wearing out so fast.
> As I recall there was no mention of using the E-brake to adjust the rear shoes in the
> owners manual.


I remember about braking backwards, but I've never heard of using the
handbrake. I think they discourage calling them 'emergency brakes' now,
on the assumption that you'll think they protect you in an emergency.
Like 'safety belts' instead of 'seat belts'. I'll try to find something
about it in the manual.

The E-brake on the 1976 monsterhome (or some other elderly vehicle, it
was decades ago that I saw this) had nothing to do with the brake, it
was a clamshell that tightened on the driveshaft.


--
Cheers, Bev
"Give me all your brains or I'll blow your money out!"
--Anonymous Unsuccessful Bank Robber
  #14  
Old August 1st 20, 03:56 AM posted to rec.autos.tech,ca.driving,alt.home.repair
rbowman
external usenet poster
 
Posts: 145
Default What metric do you use to estimate remaining brake pad life on atypical economy sedan?

On 07/31/2020 03:56 PM, The Real Bev wrote:
> The E-brake on the 1976 monsterhome (or some other elderly vehicle, it
> was decades ago that I saw this) had nothing to do with the brake, it
> was a clamshell that tightened on the driveshaft.


I don't know how many years it spanned but a '60 Plymouth with a
TorqeFlite had a drum on the tail of the tranny for the e-brake. When i
dropped in a manual, I didn't have an emergency brake. No big deal until
a state trooper asked me to demonstrate the effectiveness. Next step was
replacing the rear axle with one that had one and kludging up the
linkage. The car wasn't exactly factory stock when I got through with it.
  #15  
Old August 1st 20, 08:59 AM posted to rec.autos.tech,ca.driving,alt.home.repair
Xeno
external usenet poster
 
Posts: 336
Default What metric do you use to estimate remaining brake pad life on atypical economy sedan?

On 1/8/20 12:25 am, Arlen Holder wrote:
> On Fri, 31 Jul 2020 17:28:41 +1000, Xeno wrote:
>
>> I'm up to 100,000 kilometres on my Toyota
>> front pads and I expect many more.

>
> Thanks Xeno for understanding the question (which some who posted clearly
> didn't) and for purposefully helpfully adding another datum to the solution
> set (where the more good data we get, the better that average estimate).
>
> Assuming new pads are 12 mm with a margin of 2 mm when replaced, that means
> you attain at least 10,000km per millimeter (at least 6,000 miles per mm).
>
> So far, we have the following decent datapoints:
> o Jurid/Textar FF front pads at ~1,000 miles per mm (10,000 miles per pad)
> o The Real Bev at about 4,000 miles per millimeter (40,000 miles per pad)
> o Xeno front pads at about >6,000 miles per mm (>60,000 miles per pad)
>
> One question is how much meat is left on the pad when you replace them.
> o I'm assuming 2 mm out of the 12 mm in toto & of course, linear wear
>
> Does that sound about right?
>

Yes, that or more. I don't wear pads right down to the legal minimum either.

Previous car's pads were replaced at 80,000 kilometres and had more than
4mm remaining. This current car does mostly country highway running so
brakes last a long time whereas the previous was used in heavy city
commutes.

--

Xeno


Nothing astonishes Noddy so much as common sense and plain dealing.
(with apologies to Ralph Waldo Emerson)
  #16  
Old August 1st 20, 08:59 AM posted to rec.autos.tech,ca.driving,alt.home.repair
Peeler[_3_]
external usenet poster
 
Posts: 1
Default What metric do you use to estimate remaining brake pad life on a typical economy sedan?

On Fri, 31 Jul 2020 20:56:32 -0600, lowbrowwoman, the endlessly driveling,
troll-feeding, senile idiot, blabbered again:


> I don't know


Which won't stop you from blathering and gossiping about each and every
topic in this world, eh, senile lowbrowwoman? <G>
  #18  
Old August 2nd 20, 06:31 AM posted to alt.home.repair,rec.autos.tech,ca.driving
Arlen Holder[_5_]
external usenet poster
 
Posts: 14
Default What metric do you use to estimate remaining brake pad life on a typical economy sedan?

On Fri, 31 Jul 2020 14:04:50 -0700 (PDT), trader_4 wrote:

> Every pad I've installed for decades has had them, including the ones that
> use electric wear sensors.


How many miles do you get per front pads, in general?

As for mechanical sensors, my bimmer has only one wear sensor per axle
o No mechanical sensor; only electronic (front left and rear right).

Although electronic is essentially mechanical, since it's a stub of plastic
that wears on contact, exposing the wires embedded inside that plastic.

One issue is removing the sensors often breaks them if you're not careful.

Since we rotate so frequently, checking brakes are easy; but this question
was for estimating miles for someone else who doesn't rotate as frequently
as I do (due to mountainous terrain causing specific "camber scrub" wear to
the inboard corners of the front tires).

At the moment, with the data we have, it's about 4,000 miles per pad mm.
--
Usenet works best when helpful adults share ideas politely with each other.
  #19  
Old August 2nd 20, 05:28 PM posted to alt.home.repair,rec.autos.tech,ca.driving
Steve W.[_6_]
external usenet poster
 
Posts: 1,132
Default What metric do you use to estimate remaining brake pad life ona typical economy sedan?

Arlen Holder wrote:
> On Fri, 31 Jul 2020 14:04:50 -0700 (PDT), trader_4 wrote:
>
>> Every pad I've installed for decades has had them, including the ones that
>> use electric wear sensors.

>
> How many miles do you get per front pads, in general?
>
> As for mechanical sensors, my bimmer has only one wear sensor per axle
> o No mechanical sensor; only electronic (front left and rear right).
>
> Although electronic is essentially mechanical, since it's a stub of plastic
> that wears on contact, exposing the wires embedded inside that plastic.
>
> One issue is removing the sensors often breaks them if you're not careful.
>
> Since we rotate so frequently, checking brakes are easy; but this question
> was for estimating miles for someone else who doesn't rotate as frequently
> as I do (due to mountainous terrain causing specific "camber scrub" wear to
> the inboard corners of the front tires).
>
> At the moment, with the data we have, it's about 4,000 miles per pad mm.


There is no rule of thumb for brake wear because it depends more on the
driver, vehicle location and the pad materials than anything else.

Drive out in the plains where the only hills are long and low and the
brake wear is going to be much different than if you live in the
rockies. Same with driving in New York City versus San Fransisco.

Another factor is the vehicle itself and how it is set up. Some will
chew through brakes fast while others barely nibble. Some will go
through brakes in 40K or less while others might make it to the junkyard
on the OEM rears pads.


The Journey we have had all the brakes done by the dealer with OEM
parts prior to our purchase, They have about 55K on them and the fronts
are worn maybe 1/2 way. The rears however were just replaced, but not
for wear, the rotors rusted into junk and damaged the pads. So it got
new NAPA coated rotors and premium ceramics to see how they work on it,
have had very good service from them on many other vehicles.


--
Steve W.
 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
brake lines: mix US and metric? George[_23_] Technology 4 August 5th 09 04:20 AM
Does brake fluid have a shelf life? metspitzer[_2_] Technology 52 December 22nd 08 07:08 AM
[e39] OEM brake rotor life expectancy? Pete[_8_] BMW 14 December 18th 07 10:43 PM
Brake life expectancy LurfysMa Technology 7 June 21st 05 04:29 PM
brake pad shelf life vs. humidity Dan Jacobson Antique cars 0 July 19th 03 08:20 PM


All times are GMT +1. The time now is 12:02 AM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2020, Jelsoft Enterprises Ltd.
Copyright 2004-2020 AutoBanter.
The comments are property of their posters.