It is odd, rear pads generally last at least two sets of front pads. (In a hard stop, more than 90% of the braking is being done by the front brakes. In fact there is a device called a proportioning valve which reduces the pressure to the rear brakes to reduce the chance of lockup which would activate the ABS.)
What was the reason you needed rear pads? Excess wear? Was it warranteed?
It's widely reported that the BMW 3 and 5 series wear the rear brakes out faster than the fronts. This has been my experience on three 3's and two 5's.
Some have speculated that the DSC is often applying the rear brakes on hard acceleration. I don't drive that hard regularly but have always replaced the rears first on these cars.
I have read that the rears go out quicker because the cars apply them automatically for some scenarios. The two I remember being cruise control and traction control.
BTW my car was saying it was going to need rears soon and upon visually inspecting things found it was lying to me. Since it is still under warranty I mentioned it to the dealer while they had it, they looked at the pads and reset the computer due to it clearly lying about when things need to be done. But I am a far cry away from the OP's mileage, I am sitting right around 31k miles right now.
I was at the dealership yesterday because I'm hearing a lot of squealing coming from the back brakes as well as a metallic scratching sound.
He said the backs are worn and the sensor is probably touching the rotors. I could get them replaced right now but as it still shows 900 on the rear brakes, I am waiting in an attempt to get the rotors below the threshold and replaced before my free maint ends.
The SA did say that the rear brakes do wear quicker than the front ones. Something about how it applies them to prevent oversteer.
I noticed on a cross-country trip last year that when I used the cruise control to decelerate by pulling the stalk in to decrease speed at 5 mph intervals, the car appeared to brake down to the new speed selected. When I disengaged the cruise, no braking was evident. My admittedly unsupported belief is this could be a major factor in the rear brakes needing replacement prior to the fronts.
I haven't decelerated using the cruise control since.
I'm having a hard time believing the "DSC and traction control" theory. I've probably driven aggressively enough to trigger those things maybe 20 times in the life of the car. And for short bursts, not long drawn out sessions. (I know, shame on me). I also have AWD, so the traction control is less of a factor....if at all.
Perhaps they just overcompensated...giving the fronts way more than they needed? I know the front rotors are bigger...not sure how much bigger. I don't know. I'm just glad I got them changed under warranty.
My rear pad were changed at 40000 miles and I am still on original front brakes (pads and rotors) at 70000 miles. This despite I have heavy traffic every day. Go figure.
I've used cruise control maybe 5-6 times in the past 2 years. I don't think this explains the 15k-mile difference in the CBS indicator, claiming that the rear brakes will be due 1st.
DSX - any luck with taking the temperature measurements? I might have to beat you to it by using my fine, laser thermometer, which gets its typical workout with our outdoor pizza oven.
I've used cruise control maybe 5-6 times in the past 2 years. I don't think this explains the 15k-mile difference in the CBS indicator, claiming that the rear brakes will be due 1st.
With my car it was claiming rear brakes were due soon and it was not the truth at all. I know this happened to one of my friends as well. As far as why that happened then who knows for sure, perhaps BMW programmed flawed logic to calculate wear on the pads based upon assumptions "traction control" and cruise control and so on would be used more often OR perhaps it is flawed logic in how it calculates wear/tear when those items are used OR ... well who knows for certain.
How do you deal with this then? Do you just ignore the warnings on the idrive until they're actually due for a change? Can dealerships get out of completing warranty type work by claiming that you did not have the brakes changed on schedule?
In my case I had seen my brake pads were fine when at a tire shop. So next time I was at the dealer for some other service I told the that the rear brake indicator is coming soon and can they look at the pads. I never told them I had looked at the pads. They looked at it and said pads are fine and reset the computer. I forget how he explained the reset though because it did not seem like they simply told the car it had a rear brake job.
Cheers. My experience of dealers suggests that they are more likely to tell you that you need brake pads when you don't! Sounds like yours is one of the good ones.
My car, which I purchased a month ago at 6 month old, is saying 24000 miles before the rears need changed and 34000 for the fronts. I've no idea how it was driven before I got it though. For what it's worth, I've covered about 1000 miles since purchase and the readout hasn't changed.
Cheers. My experience of dealers suggests that they are more likely to tell you that you need brake pads when you don't! Sounds like yours is one of the good ones.
My car, which I purchased a month ago at 6 month old, is saying 24000 miles before the rears need changed and 34000 for the fronts. I've no idea how it was driven before I got it though. For what it's worth, I've covered about 1000 miles since purchase and the readout hasn't changed.
Well, I'd be fine with getting new pads for free when not really needing them yet. It just extends the time until I will need them outside of the free maintenance period and have to then pay for them.
This thread made me go look at mine. Computer is saying 15k left on the fronts, 6k on the rear. Not bad considering there's 82k miles on them at the moment.
Really?? Should I be concerned that my idrive is saying 24,000 miles after only 7k on the clock? Or do you think that I will get a bit more and that the readout will readjust as time goes on. I'm only driving a 320d and tend to be fairly conservative.
The number is a predictor, and nothing really counts until you hit the "time to replace me" wear sensor in the pads themselves. The computer looks at your driving habits and makes a calculation based on what it thinks you'll need.
In my case, I drive down my street, applying the brakes on one curve and a stop sign. Then, I get on the highway and head for work. If I don't stop for coffee along the way, I'll drive 25 miles before using the brakes on the off-ramp, 2 lights, and the parking lot at the office. For the ride home, pretty much the same. The computer sees I do a ton of miles without ever touching the pedal, so it figures they'll last a long time. On the weekends, we tend to use my wife's car, as it's typically the one at the tail end of the driveway, so I don't get the stop/go errand effect.
In your case, I'd guess you have more stop and go situations requiring more brake use, so the computer's guessing you'll need them sooner. As there's no active sensing of wear at your current point, there shouldn't be anything to worry about.
I heard that the brake maintenance is just an "inspection." They dont replace your brakes if it does not need to be. Mine is not due until 28k and I have only 6k, still long way to go. I might not even get there before the F32 comes out, which is when i will trade it in.
Thanks for the response. I'm hopeful that I might get a bit more out of my brakes then. I'm guessing that the idrive will be basing its estimates on the previous owner as it hasn't changed in the 1000 miles I've completed.
I got my CPO at the end of May with it showing 1100 miles until the service. I've driven around 3.5k miles since then, and it has not moved from 900 miles in a while.
There was 1 day it showed that a service was needed, but since then it appears the mileage has slightly increased again as a brake service is not needed.
Wow! My 06 330i just hit 71K and over the weekend my front brake sensor went off. Now, I'm wondering if the extended warranty covers brakes? I don't hear any noises or nothing, but since they are original it's probably time. My rears still have some miles left, but will definitely have my Indy guy take a look at them this weekend. I haven't driven her for the last few days, but would it be okay to drive the car for a few days? There's the service indicator with the car on something (don't know the name of it) that is also red, so this makes me wonder if I can continue to drive it...
I qualify my E90 front brakes as outstanding, as per all quantifiable and qualitative criteria, except for dust of course.
I still have my original front brakes at 70000 miles.
But I don't drive it on highways. My driving is probably 80% city, including daily insane traffic.
BTW, your 328i 2008 front brakes are different from 328i 2007. Like my 2007 323i, 2008 328i have 312mm rotors and 2007 328i have 300mm. Confusing hey? It did cost me 100$ to learn this....
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