# Brake job



## bmwowner (Mar 29, 2004)

Is it unusual to need fromt and rear brakes done at the 15,000 mile maintenance interval


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## Tom S. (Nov 15, 2003)

bmwowner said:


> Is it unusual to need fromt and rear brakes done at the 15,000 mile maintenance interval


What car model and year?

This is what I have gotten out of my brakes, my original fronts lasted about 50K and the replacement about 42K, the original rears were replaced at 82K and that is on E39 which is a heavy car and is not driven lightly.


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## bmwowner (Mar 29, 2004)

*Brakes*



Tom S. said:


> What car model and year?
> 
> This is what I have gotten out of my brakes, my original fronts lasted about 50K and the replacement about 42K, the original rears were replaced at 82K and that is on E39 which is a heavy car and is not driven lightly.


2001 325i; its a purchase of a preowned car which I am about to make and wanted to understand if this was an indication of anything.


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## rwg (May 10, 2002)

It's an indication of something. It could be track schools, just very hard driving, constant aggressive city driving, or a batch of soft pads. Some people don't get the first brake replacement in during the free maintenance period. Other people go through them like candy.

Is it an auto transmission? I would want to look into it more if it were a manual, but an auto in rush hour will go through brakes pretty quick.


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## The HACK (Dec 19, 2001)

Who told you you need new brakes? The dealership?

From your reference to "15,000 mile" maintenance, I assume you took the car to a dealership for the "maintenance" and they told you you need new brakes?

Common dealership practice. I have a friend with a 7 series that used to take it to his dealership for service, and every time he stopped by they said he need new pads and rotors. That's every 15,000 miles. Finally he got fed up and bought an extended SERVICE package for the car and after that, every time he goes in for service they NEVER mentioned anything about the brakes needing service. His driving habid and route hasn't changed.

They figure the brakes is one thing that most people don't question and that they could BS their way into getting you to pay for brake changes prematurely. You will not believe how gullible most consumers on the market is. And since the brakes are not covered under warranty (wear item) and they make enormous margins on it ($600 for a $100 job in parts, you go figure it out), if they suspect you don't know a thing about brakes they'll pull this little stunt on you.

You don't need new brakes.


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## RKT BMR (Sep 7, 2002)

The HACK said:


> You don't need new brakes.


While I don't doubt HACK's opinion on this, I would check the pad thickness regardless (or if they did, ask them how much was left on each of the 8 pads -- in mm, not %), then check against specs. The gang here can probably cough up what the minimum allowable pad thickness is -- it might even be in my Bentley... I'll check 2nite.

Brakes are not something to be casual about. 15k seems awefully low to me -- I just had my rears done at 45k -- so HACK may very well be right on the mark. However, you need to be sure.


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## Kaz (Dec 21, 2001)

Since this is an 01, its original maintenance is probably out. I sorta agree with HACK; if it was still under maintenance, they probably wouldn't have done it unless the pad-out light was on, or you asked them to check rotor thickness (I did, at 26k on a MT car with no track time, and they replaced everything). If this was on your dime, an unscrupulous dealer would just tell you to pay them to put new parts in.

15k is on the low side, though not completely unheard of. At least a couple of people here need brakes every <10k.


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## The HACK (Dec 19, 2001)

RKT BMR said:


> While I don't doubt HACK's opinion on this, I would check the pad thickness regardless (or if they did, ask them how much was left on each of the 8 pads -- in mm, not %), then check against specs. The gang here can probably cough up what the minimum allowable pad thickness is -- it might even be in my Bentley... I'll check 2nite.
> 
> Brakes are not something to be casual about. 15k seems awefully low to me -- I just had my rears done at 45k -- so HACK may very well be right on the mark. However, you need to be sure.


21 mm for the front and 19 for the rear on the 325s.


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## Kaz (Dec 21, 2001)

The HACK said:


> 21 mm for the front and 19 for the rear on the 325s.


er, those don't sound like minimum OR maximum thicknesses unless you're missing a decimal.


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## The HACK (Dec 19, 2001)

Kaz said:


> er, those don't sound like minimum OR maximum thicknesses unless you're missing a decimal.




Don't make me whip out the trusty TIS across your fo'head.

Okay, the minimum thickness for front rotors is 20.4mm and the rear is 17.4mm. OEM dimention for the 325 brakes are 22mm thick and 19mm thick. Straight from the horses' mouth (TIS).


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## Kaz (Dec 21, 2001)

The HACK said:


> Don't make me whip out the trusty TIS across your fo'head.
> 
> Okay, the minimum thickness for front rotors is 20.4mm and the rear is 17.4mm. OEM dimention for the 325 brakes are 22mm thick and 19mm thick. Straight from the horses' mouth (TIS).





RKT BMR said:


> While I don't doubt HACK's opinion on this, I would check the pad thickness regardless (or if they did, ask them how much was left on each of the 8 pads -- in mm, not %), then check against specs. The gang here can probably cough up what the minimum allowable pad thickness is -- it might even be in my Bentley... I'll check 2nite.


Foolio, he said PADS not ROTORS.


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## The HACK (Dec 19, 2001)

Kaz said:


> Foolio, he said PADS not ROTORS.


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## doeboy (Sep 20, 2002)

The HACK said:


>


 :rofl: :lmao: :bustingup

Yeah... unfortunately when I was looking through the TIS I was unable to find anything about PAD thickness either...

I think I read some thread here that mentioned 3mm is about the time they'll say you need new brakes? Or was that about when the brake wear sensor breaks.... hmm... :dunno:


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## Desertnate (Mar 11, 2002)

The HACK said:


>


 :rofl:

I was beginning to wonder too...

Are brake pads even 21mm thick from the start?


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## RKT BMR (Sep 7, 2002)

Kaz said:


> Foolio, he said PADS not ROTORS.


Yeah, foolio! :rofl:


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## RKT BMR (Sep 7, 2002)

Kaz mentioned the pad-out light -- don't let the cretins pull that one on you if you're still in the maintenence period. That sensor system is notoriously unreliable. If we had a poll, I'd pick it as the most unreliable indicator on the 3 series.

Make them measure the thickness of the pads, and insist that they do the brakejob if they are below minimum spec -- which, IIRC, is thicker than the point at which the sensor will, perhaps, if your lucky, and didn't torture any small animals or insects when you were a kid, nor beat up your sister, and also always went to church on Sundays, even if you're Jewish... will light.

I just went through this, and had to mildly argue with my service rep to get them to do the rears, which after 45k miles, were more than ready. I was even getting the very early faint squeel of the pad "your about to start grinding your rotors" safety blob built in to every pad. Still, *no damn light* (I tortured insects with matches when I was a yute  ). Rep tried to use that on me to say it didn't need a brakejob yet. I knew better, told him to have the tech measure the pad thickness and get back to me, and when he called he didn't even argue -- just said the brakes would be done, covered under ful maintenence.


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## doeboy (Sep 20, 2002)

So anybody know just what is the minimum spec for brake pad thickness?


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## Desertnate (Mar 11, 2002)

RKT BMR said:


> That sensor system is notoriously unreliable. If we had a poll, I'd pick it as the most unreliable indicator on the 3 series.


:hi:

Coun't me in that group. I only knew the brakes were about gone due to the squeeler. No light at all...


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## Desertnate (Mar 11, 2002)

doeboy said:


> So anybody know just what is the minimum spec for brake pad thickness?


4mm is what seems to stick in my mind, but I honestly can't remember where I heard that from...


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## Kaz (Dec 21, 2001)

Odd, I've never seen the little metal 'spealer' clip on any E36/E46 brake pad. They're always on Japanese application pads, though.


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## James (Jun 30, 2004)

The HACK said:


> 21 mm for the front and 19 for the rear on the 325s.


 Do you know if these numbers are the same for a 2001 330Ci? I just checked when switching to my summers and I am at 24.8mm front and 20.8mm rear...assuming I used my cool new digital calipers right .

I have done a search but I think I am search challenged so I figured I'd add to an existing thread .

James.


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## AG (Apr 24, 2002)

James said:


> Do you know if these numbers are the same for a 2001 330Ci? I just checked when switching to my summers and I am at 24.8mm front and 20.8mm rear...assuming I used my cool new digital calipers right .
> 
> I have done a search but I think I am search challenged so I figured I'd add to an existing thread .
> 
> James.


330 rotors are thicker. Can't remember off hand what they are though. The min thickness is stamped onto the rotor hub. Add 1.6 mm to get the thickness when new.

Edit: 330 front rotors are 25mm thick when new.


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## James (Jun 30, 2004)

AG said:


> 330 rotors are thicker. Can't remember off hand what they are though. The min thickness is stamped onto the rotor hub. Add 1.6 mm to get the thickness when new.
> 
> Edit: 330 front rotors are 25mm thick when new.


 Ah, that's what that number was :thumbup:. Thanks.

James.


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## jayf (Aug 26, 2004)

*m3 re46 otor thickness*

I have a '02 m3C w/ 67K. Do you guys know what the thickness of my front rotors should be before needing to change them? Some people say change them with every pad replacement and others say every other pad change. I thought better I go by the book.


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## doeboy (Sep 20, 2002)

jayf said:


> I have a '02 m3C w/ 67K. Do you guys know what the thickness of my front rotors should be before needing to change them? Some people say change them with every pad replacement and others say every other pad change. I thought better I go by the book.


26.4mm is minimum spec for front rotor thickness according to the TIS.


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## toddkageals (May 5, 2003)

I have changed the front and rear pads on my 2000 328i and the fronts on my friends '99 232is. Neither set of pads had the "squealer finger" mentioned in some of the posts above. The three sets of pads I have changed were all done when the indicator lights up on the dash. The indicator comes on with approximately 2mm-3mm of friction material remaining on the pad (from my own measurement, not from any spec. sheet so take it fwiw). If installed correctly, it would be difficult for that sensor to fail in my opinion. I drive my car agressively but have not ever had it on a race track/driving school/autocross course (although I'd love to do all of that). I consider myself a pretty good mechanic. I can install/rebuild engines etc. (not on my bimmer though . I did not replace rotors on my car when I did the pads at about 45,000 miles. The rotors showed some wear but were not badly grooved and were not warped at all. BMW says to replace the rotors with every pad change but I think that for street driving you can go every other pad replacement with the rotors. However, I am not a professionaly trained BMW mechanic so what I expressed was only a personal opinion.

Todd


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## roadkiller99 (Dec 25, 2012)

I new to BMW but not to brakes. No brake on but the 325 is starting to sound like a slight metal scrape. Question is can you cut these rotors? Also what are pads that throw out light dust or can you get a dust cover for these 17 inch rims 2004 325ci. 

Thanks Roadkiller


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