Need brake pads/rotors replacement advice

[newm5]

the brake pad light on my 2000 328i just went on last week. I have received a quote from the dealer asking for $460 to have the front rotors, pads and sensor replaced. he thinks its the front brakes that need to be replaced. the car has 44K miles in it.

I am surprised that the rotors would wear out this soon. i thought i can just replaced the pads. shouldn't the rotors last longer than 45K?

[ger3sf]

The F&R pads and rotors on my 99 Z3 (@56K miles) were replaced about 3 wks ago after the brake light came on. A local dealer was quoting around $900, so I went to an independent BMW garage (Phaedrus in SF, CA). The total was around $730, incl. the BMWCCA 10% parts discount.

[HW]

maybe drive up to canada to get it done. :dunno:

http://www.bmw.ca/service/service_valueservice.asp?lang=en

[Desertnate]

I too was quoted $460 for the fronts... :rolleyes:

I was able to find an independant shop that will do all four corners for $650 :thumbup:

As for the rotors...

You need to replace them as well. They wear along with the pads. When the pads need to go, your rotors will most likely be below specs as well. For me, the fronts have worn out all together, whereas my rear rotors were able to survive a second set of pads prior to their need for replacement.

[HW]

I too was quoted $460 for the fronts... :rolleyes:

I was able to find an independant shop that will do all four corners for $650 :thumbup:

As for the rotors...

You need to replace them as well. They wear along with the pads. When the pads need to go, your rotors will most likely be below specs as well. For me, the fronts have worn out all together, whereas my rear rotors were able to survive a second set of pads prior to their need for replacement.

mine seems to be wearing evenly. :dunno: and i can feel the amount of rotor that's been worn off. the very edge of the rotor is not worn whereas the inner surface has significantly shaved. know if this is normal? :dunno:

[Artslinger]

Man dealers are such a rip...

what maybe 100 bucks a axle tops for parts, and maybe an hour to a hour and half labor.

[KP]

Would be a good idea to replace the rotors, as BMW rotors are thin. If you have worked on your a bit before, it's really not that hard to change the pads and rotors, if you have the proper tools. But an independent shop will probably charge you for less to have them done if you feel that you cannot change them yourself.

[apar330i]

mine seems to be wearing evenly. :dunno: and i can feel the amount of rotor that's been worn off. the very edge of the rotor is not worn whereas the inner surface has significantly shaved. know if this is normal? :dunno:
Normal. The ridge created is due to the pads not covering the entire surface area of the disc. When discs are resurfaced part of what they do is remove the ridge so the entire surface is the same. Depending on the original thickness of the rotors some can be machined to remove the ridge and be used for another set of pads. If I recall there is a legal limit as to how much can be machined before a disc is considered unuseable. I thought it was .0090 but am not sure anymore. I'm assuming with the BMW discs by the time the brakes are at the limits they have exceeded these limits thus not machinable. I think this is about right, anyone else?

[Desertnate]

Normal. The ridge created is due to the pads not covering the entire surface area of the disc. When discs are resurfaced part of what they do is remove the ridge so the entire surface is the same. Depending on the original thickness of the rotors some can be machined to remove the ridge and be used for another set of pads. If I recall there is a legal limit as to how much can be machined before a disc is considered unuseable. I thought it was .0090 but am not sure anymore. I'm assuming with the BMW discs by the time the brakes are at the limits they have exceeded these limits thus not machinable. I think this is about right, anyone else?

I don't know about how much you can have milled off, but I was told the materials used in making the OEM rotors not only makes for great brake performance, but also causes the rotors to wear down as the pads go. This results in rotors at/near minimum limits by the time the pads are shot.

[HW]

Normal. The ridge created is due to the pads not covering the entire surface area of the disc. When discs are resurfaced part of what they do is remove the ridge so the entire surface is the same. Depending on the original thickness of the rotors some can be machined to remove the ridge and be used for another set of pads. If I recall there is a legal limit as to how much can be machined before a disc is considered unuseable. I thought it was .0090 but am not sure anymore. I'm assuming with the BMW discs by the time the brakes are at the limits they have exceeded these limits thus not machinable. I think this is about right, anyone else?

that was my guess as to where the ridge comes from. i was just not sure if that is what supposed to happen ... like are my pads in the right position.

[apar330i]

I don't know about how much you can have milled off, but I was told the materials used in making the OEM rotors not only makes for great brake performance, but also causes the rotors to wear down as the pads go. This results in rotors at/near minimum limits by the time the pads are shot.
True, I hadn't considered the material composition. The pads also are a factor. Depending on the type they can eat rotors as well.

[apar330i]

that was my guess as to where the ridge comes from. i was just not sure if that is what supposed to happen ... like are my pads in the right position.
I think your brakes are fine, the ridge is normal. :thumbup:

[HW]

just got call from sa. pads down to 5%f / 10%r and rotors below min spec. :eek: strange that the sensors did not light up. :confused:

[apar330i]

just got call from sa. pads down to 5%f / 10%r and rotors below min spec. :eek: strange that the sensors did not light up. :confused:
Time for a brake job. Good thing you had them checked, sucks that the sensors didn't go off. Kinda defeats the purpose of having them.

[HW]

Time for a brake job. Good thing you had them checked, sucks that the sensors didn't go off. Kinda defeats the purpose of having them.

my car's in for the glorified (spelled overpriced oil service :tsk: ) oil change, brake fluid flush and now rotors/pads. :eek:

looking back, i don't think the oil "service" was necessary. i recently had my cam position sensor changed and had the engine controller diagnosed and i also had my car undercarriage and mechanicals inspected just before my warranty expired.

[apar330i]

my car's in for the glorified (spelled overpriced oil service :tsk: ) oil change, brake fluid flush and now rotors/pads. :eek:

looking back, i don't think the oil "service" was necessary. i recently had my cam position sensor changed and had the engine controller diagnosed and i also had my car undercarriage and mechanicals inspected just before my warranty expired.
I had to replace the back breaks on my 328 and went to an independent shop. They were a little cheaper and at my request used PBR pads versus OEM. The difference in dust was like night and day.

[Galun]

It's really easy to change brake pads and rotors yourself. I think you should give it a try.

Here are some instructions from e46fanatics: http://www.e46fanatics.com/howto/howtodetail.php?howto_id=29

Parts should cost you around $50 / rotor + $70 / pair of pads + $15 for the sensor = <$200 for parts, so they want to charge $260 for labor, which equates to about 2.5 - 3 hours of work. I have done it maybe a dozen times (so I am not a mechanic by any means) and it takes me 15 minutes per wheel. That includes time needed for jacking up the car.

I'd say, order the parts first, then try to do them on your own. If all else fails, put everything back together, and go have it done at a shop.

[DZeckhausen]

I don't know about how much you can have milled off, but I was told the materials used in making the OEM rotors not only makes for great brake performance, but also causes the rotors to wear down as the pads go. This results in rotors at/near minimum limits by the time the pads are shot.The materials used in the OEM rotors (Balo) are virtually identical to the materials used by Zimmerman, ATE, Brembo, and other aftermarket suppliers and are also identical to those used by other manufacturers such as Mercedes. This idea that BMW rotors are somehow "softer" than other rotors in order to enhance performance is a lie perpetuated by service advisors who fail to treat their customers with the respect they deserve.

BMW made compromises in the design of their rotors to enhance performance, in terms of handling and rotor cooling ability. The BMW friction plates are thinner in order to reduce unsprung/rotating weight and to allow for a larger air gap between them to enhance airflow through the rotor. Whereas Mercedes' thicker friction plates allow 2.4mm of rotor wear, BMW specifies only 1.6mm of allowable wear. So the 300mm x 22mm rotors on your car should be discarded when they reach a thickness of 20.4mm. So a Mercedes rotor will last 50 percent longer than a BMW rotor (all else being equal) but it will be heavier and it won't be able to shed heat as efficiently.

When your "CHECK BRAKE LININGS" warning (or idiot light on some models) goes off, it means that you have about 2mm of pad thickness remaining. You started with about 12mm. So you drive to the dealer and they check out your brakes, only to discover that your rotors are worn down by just under 1mm. You have 45 percent life remaining in those rotors, but the dealer knows if he replaces your pads and wear sensor, you won't be coming back for service again until the warning appears on your dash again. The odds are good that your rotors will be BELOW the minimum recommended thickness at that time. In order to protect you from danger and to protect himself from liability, he opts to replace the rotors. Rather than respecting you for having a brain and some good judgment, he doesn't present the facts to you and let you make the decision. Instead, he lies and tells you the rotors are worn out and must be replaced. He explains that BMW rotors are carefully engineered to wear at the same rate as the pads and that this is normal. He might be making the right judgment call to replace the rotors, but he's not allowing the customer to become involved in the decision. And, in the process, he is causing false information about BMW brakes to be spread around as if it were fact.

[DZeckhausen]

Normal. The ridge created is due to the pads not covering the entire surface area of the disc. When discs are resurfaced part of what they do is remove the ridge so the entire surface is the same. Depending on the original thickness of the rotors some can be machined to remove the ridge and be used for another set of pads. If I recall there is a legal limit as to how much can be machined before a disc is considered unuseable. I thought it was .0090 but am not sure anymore. I'm assuming with the BMW discs by the time the brakes are at the limits they have exceeded these limits thus not machinable. I think this is about right, anyone else?Partly right. The ridge is caused by the fact that the pads don't go all the way to the outside edge. I like the ridge. It allows me to reach in between the spokes and tell, in seconds, if the rotors are close to requiring replacement. (Warning: don't do this with a car that has just been driven hard or you will burn the $#*@ out of your finger!)

There is no "legal" limit to machining a disc other than not taking it below the minimum "engineering" limit stamped on the edge of the rotor. For the 2000 328i, the rotors were 22mm thick when new and are allowed to wear down to 20.4mm before being discarded. Thus the maximum amount which could ever be removed is 1.6mm total or 0.8mm (.003") per side. Of course, that would render the rotor useless!

In general, you should not machine rotors unless there are symptoms of uneven pad deposition or (on rare occasions) excessive runout. These symptoms include vibration under braking and uneven friction levels during gentle stops. My preference in these cases is to simply replace the rotors, since they are so inexpensive on the non-M BMW models. You need to take into account the cost of service and the remaining life when making the decision to replace vs machine. And in many cases, a simple rebedding of the brakes will cure pad deposition symptoms for free. See: http://www.zeckhausen.com/bedding_in_brakes.htm

[Desertnate]

The materials used in the OEM rotors (Balo) are virtually identical to the materials used by Zimmerman, ATE, Brembo, and other aftermarket suppliers and are also identical to those used by other manufacturers such as Mercedes. This idea that BMW rotors are somehow "softer" than other rotors in order to enhance performance is a lie perpetuated by service advisors who fail to treat their customers with the respect they deserve.

*snip*



Wow! Thanks Dave, great explination :thumbup: Funny part about your opening remarks is that I have talked with owners of other makes who have recieved the same story from their service folks...Jag in particular.

So...after your explination, is there a "true" minimum that should be the guide, or is the 1.6mm of wear still a good number to go buy? If only 1mm typically wears with 10mm of pad (I know it is just an example) and .6mm is left, you could almost get two sets of pad out of the life of the rotor. At the same time, I would think it would take consistant careful measurement of the rotors on a very regular basis. For me that is difficult as I don't right now have anything that would accuratly measure in mms let alone fraction of mms.

So in an effort to keep from constantly having to take the car in for seperate work (in my case untill I have the tools and knowledge to do it myself) do we just suck it up and replace the pads/rotors at the same time for the fronts? :dunno: I'm at that point now.

[DZeckhausen]

So...after your explination, is there a "true" minimum that should be the guide, or is the 1.6mm of wear still a good number to go buy? If only 1mm typically wears with 10mm of pad (I know it is just an example) and .6mm is left, you could almost get two sets of pad out of the life of the rotor. At the same time, I would think it would take consistant careful measurement of the rotors on a very regular basis. For me that is difficult as I don't right now have anything that would accuratly measure in mms let alone fraction of mms.

So in an effort to keep from constantly having to take the car in for seperate work (in my case untill I have the tools and knowledge to do it myself) do we just suck it up and replace the pads/rotors at the same time for the fronts? :dunno: I'm at that point now.Actually, it's hard to generalize because different pad compounds will wear the rotors at different rates. And just saying "OEM pads" does not fully characterize the situation because BMW uses different pad compounds on different models. For example, the BMW M5 has a unique part number for the front brake pads. Yet those same pads will fit the 530i, 540i, 740i, and X5. The only difference is the compound used.

The bottom line is that you should measure the thickness of the rotor (inboard of the raised lip) with a micrometer (they are cheap) or a measuring caliper to help decide if you should replace the rotor. Also, if it's slightly less than 50 percent remaining, keep in mind that there is some engineering margin built in. If you wear the rotors down by more than 1.6mm, they won't explode. I replaced the rotors on a customer's 528i which were worn down by more than 2.5mm. I am NOT condoning such abuse, but I just want to point out that 1.6mm wear is the recommended discard thickness and there is some leeway.

If you live in a climate that requires you to switch back and forth between summer wheels and winter wheels (or if you autocross) you will have plenty of opportunities to inspect the rotors. Unless your driving conditions change radically, the rate of rotor wear should remain fairly constant and it should be possible to extrapolate the expected lifetime from your measurements.

[Desertnate]

Great info...I figured there was some tolerances built in, but not that much.

Thaks for the advice Dave. I really appreciate you and others who are knowledgable in this are providing objective "third party" advice.

[HW]

does this sound reasonable? 4 tech hrs for all 4 brakes and rotors? :confused: whereas here, peeps say it can be done for 2.5 to 3.0 hrs? 15 min per wheel etc. :dunno:

completing my service w/ the addition of rotors and pads only took 2 more hours yet bmw canada lists 4 tech hrs. i guess maybe they had 2 techs working on it? :dunno:

re: rotor and pad wear, i got 50000km (30Kmiles) on my pads and rotor. rotors were past min and pads had 5%/10%. is that bad or good?

[apar330i]

Partly right. The ridge is caused by the fact that the pads don't go all the way to the outside edge. I like the ridge. It allows me to reach in between the spokes and tell, in seconds, if the rotors are close to requiring replacement. (Warning: don't do this with a car that has just been driven hard or you will burn the $#*@ out of your finger!)

There is no "legal" limit to machining a disc other than not taking it below the minimum "engineering" limit stamped on the edge of the rotor. For the 2000 328i, the rotors were 22mm thick when new and are allowed to wear down to 20.4mm before being discarded. Thus the maximum amount which could ever be removed is 1.6mm total or 0.8mm (.003") per side. Of course, that would render the rotor useless!

In general, you should not machine rotors unless there are symptoms of uneven pad deposition or (on rare occasions) excessive runout. These symptoms include vibration under braking and uneven friction levels during gentle stops. My preference in these cases is to simply replace the rotors, since they are so inexpensive on the non-M BMW models. You need to take into account the cost of service and the remaining life when making the decision to replace vs machine. And in many cases, a simple rebedding of the brakes will cure pad deposition symptoms for free. See: http://www.zeckhausen.com/bedding_in_brakes.htm
Thanks for the correction. When I was taking auto machine shop back in the early '80s we had to maching a rotor and drum as part of our class work. I can vaguely remember something about the limits that could be milled off before the rotor or drum was considered out of tolerance.

Yeah, it's always good to wait until the brakes have cooled before checking the ridge. Youch! :)

[newm5]

It's really easy to change brake pads and rotors yourself. I think you should give it a try.

Here are some instructions from e46fanatics: http://www.e46fanatics.com/howto/howtodetail.php?howto_id=29

Parts should cost you around $50 / rotor + $70 / pair of pads + $15 for the sensor = <$200 for parts, so they want to charge $260 for labor, which equates to about 2.5 - 3 hours of work. I have done it maybe a dozen times (so I am not a mechanic by any means) and it takes me 15 minutes per wheel. That includes time needed for jacking up the car.

I'd say, order the parts first, then try to do them on your own. If all else fails, put everything back together, and go have it done at a shop.

Galun,

thx for the info.. now that I plan to do this myself, how do I know whether I will need all 4 pads and rotors replaced or just the front? the brake pad light warning didn't specify which side needs to be replaced.

[HW]

Galun,

thx for the info.. now that I plan to do this myself, how do I know whether I will need all 4 pads and rotors replaced or just the front? the brake pad light warning didn't specify which side needs to be replaced.

either use a micrometer or guestimate the depth difference between the raised edge or the rotor and the inner surface of the rotor to be greater than or less than 0.8mm. if the depth is more than 0.8mm (double that for 1.6mm both sides of the disk), then time to replace it.

[Galun]

Jack up the car and remove the front driver side or rear passenger side wheel, and see which sensor is worn out.

Which part of the bay area do you live in?

[newm5]

Jack up the car and remove the front driver side or rear passenger side wheel, and see which sensor is worn out.

Which part of the bay area do you live in?

I live in San Ramon.

[elader]

maybe drive up to canada to get it done. :dunno:

http://www.bmw.ca/service/service_valueservice.asp?lang=en

Anyone notice that when you do the conversion, this is $500 US dollars for all 4 brakes and rotors from BMW?????

Canada can be lovely in the summer...

[HW]

Anyone notice that when you do the conversion, this is $500 US dollars for all 4 brakes and rotors from BMW?????

Canada can be lovely in the summer...

service rate is $105CAD/hr and parts are at shop price (discounted to ~cost).

[blazingbeat]

maybe drive up to canada to get it done. :dunno:

http://www.bmw.ca/service/service_valueservice.asp?lang=en

Wow, even BMW service in Canada is socialistic :p

[newm5]

It's really easy to change brake pads and rotors yourself. I think you should give it a try.

Here are some instructions from e46fanatics: http://www.e46fanatics.com/howto/howtodetail.php?howto_id=29

Parts should cost you around $50 / rotor + $70 / pair of pads + $15 for the sensor = <$200 for parts, so they want to charge $260 for labor, which equates to about 2.5 - 3 hours of work. I have done it maybe a dozen times (so I am not a mechanic by any means) and it takes me 15 minutes per wheel. That includes time needed for jacking up the car.

I'd say, order the parts first, then try to do them on your own. If all else fails, put everything back together, and go have it done at a shop.

I called several shops here in the east bay area, none of them are willing to do the work if you bring your own rotors/pads. can you recommend a shop in the SF area maybe?

also, where are you getting these price quotes? not from a dealer I assume, because the price they quoted me (east bay BMW) were at least double the price you have above.

[Nick325xiT 5spd]

Man. You sure got a lot of wear out of your brakes. I replaced the pads and rotors in my old 325xiT three times, and then threw in a fresh set of pads the day before I gave it to carmax because the fourth set of pads wore out. What I found was that the OEM pads were comparatively hard on the rotors. IMHO, while it might have been OK to run the rotors a little while longer, they were pretty damned close to worn out whenever the OEM pads wore out. The lip was quite deep each time.

Interestingly enough, my Axxis Ultimates seemed a LOT less harsh on the rotors. When they wore out (which was actually a few thousand miles later than my OEM pads usually did), my rotors had a fair bit of life left.

YMMV, of course. The car was on its FIFTH set of brakes when I sold it with 44K.

And please do buy from Dave. He's been ABSOLUTELY FANTASTIC to me in the three (or was it four?) orders I've placed with him.