apetriedmd

I had both the front and rear pads/rotors replaced last month weeks apart at my local indy shop. I noticed immediately after the rears were first done about a 2 mpg drop, sometimes 3 on the highway in gas mileage. Now yes, I did not buy this car for gas mileage but the drop is noticable and somewhat significant. Nothing changed whatsoever in driving habits and daily miles logged. The car used to roll down my driveway in neutral, just barely. But now, won't budge at all. Shop says nothing wrong with brakes, but the bite (esp rears) is significant when hard braking occurs. Is this even possible!? I elected against doing my own brakes because labor wasn't much ,but parts were. Could they have been fitted too snug or the line not bled out properly. Any advice greatly appreciated.

Ravill

The rear's have an electronic component that needs to be reset for the appropriate thickness of the pads.

You can google audi rear pad change and see the special software and hardware one needs to change them.

It is VERY possible that a setting is off. Do you smell brakes when driving around?

apetriedmd

Hi, I haven't noticed really any smell or heat, but definately the lag and "bite" of the pads when I brake quickly, that's the only difference. I'm headed into Audi next week to have two recalls performed and for them to evaluate the brakes. I'm not crazy but @ a 2 -3 mpg change, its worth finding the root cause. Thank you.

the_duke

What about temperature change? If it has gotten much colder than that will effect fuel economy. Especially if you do a lot of short trips and the car doesn't have time to warm up completely.

MP4.2+6.0

You might ask indy (gently) how he did the rear brakes. In particular, did he open them with VCDS or similar electronic tool. Or, did he dynamite it w/ some mechanical forcing of it. If the latter you have the answer, though in turn something may be broken.

GR8-LIFE

I am glad i read this thread. My rears are worn down at 35K miles and I am about to replace them. I could go to the dealer or I have a shop guy who does pads for many local road racers in the area. He said there is an OEM pad avail for much less the cost but it just doesnt come in the AUDI box.

But now this thread has me concerned on who i should have do the work, Personally I have never ever read gas mileage issues linked with brake changes so its something for me to think about. And i am glad the note on software was made


BTW, my fronts have more than half, (more like 70% pad left). But my rears are worn down. That i dont get!

Redd

Sure sounds like brake drag from something being installed or reset improperly. One way to find out might be to jack up the car and spin the wheel, by hand. See if one of the rear wheels comes to a stop significantly faster than the other, or one of the front wheels. And then, pursue those questions with the brake shop about what they did.

polo1

Would be a great question for Jeremy of audionlineparts.com.

Jack88

+1, really sounds like brake drag. It's a good way to kill your rotors and calipers. Too much heat can be developed easily.

Redd

Heat!
Which reminds me, an inexpensive "IR non-contact thermometer" for $20 can give you hard numbers on the brake pads and rotors. If the rear(s) are significantly hotter than the fronts, especially after "just idling down the road"...that's a good sign of a drag problem also. Very useful tool for many odd purposes, and reasonably good enough from all kinds of cheap sources.