Replacing Front Brakes
 

Hello everyone,

I have a 2004 A8L and will be replacing the front pads and rotors myself. I've done brakes on a BMW 5series and a 1998 Cadillac. But i had some questions. First off, is there a jack point under the engine so i can use jack stands? Is the task doable without a bentley manual? What do i do when my rim is siezed to the hub?

Any info would be helpful, thanks.

I don't have a manual covering 2004 models but see that the pads are very different from D2 (2003 and before) A8's, so I would definitely consult a manual. I always use a workshop manual for brakes...although they all work by the same principle, they disassemble differently from brand to brand and model to model.

I always use only the regular jack points at 4 corners and only do one brake at a time...never saw reason to do more at the same time(?). I slide a jack stand under a solid sub frame point, near where lower suspension arm connects at inboard end, but just as a back-up for the hydraulic jack.

A wheel seized to a hub always comes off the old fashioned way for me, push-kick the tire at top with bottom of my foot...works every time :)

thanks for your help, silverd2.

after seemingly hundreds of solid kicks later the rim came off. Without a manual, the brakes aren't that difficult...however, i can't figure how to disconnect the wear sensor. The new one doesn't look exactly like the old one either.

also, just out of pure curiosity, does anybody know what the jack mode actually does? i assume i turns off auto-leveling. but what else?

Thanks again

Jack mode is what you HAVE to put your car in when you jack the car off the ground, if you don't and lift the car, it will either assume its loosing air or pumping too much (depends on sensor design) because it measures suspension travel and there would be nothing to stop the compressor from blowing up the airbag. I've never actually seen it happen on an audi, they usually deflate because the sensor is mounted on the lower control arms, but i have heard it happen on Ford Expeditions if not turned off, BANG!!!

To get sensor connection out of bracket, lift tab and turn 1/4 turn. To unplug, insert flat head screwdriver in lock on side of plug, pry back gently while pulling plug apart.

Thanks for all your help!

I've heard that the Lincoln mark VIII's had the airbag suspension and that they could be popped if not jacked up properly. And I did have the car in jack mode, i was just wondering while i wan in the wheel well, "hmm i wonder if the auto level will kick in...that would be bad" thats when i kinda figured that jack mode disabled that.

Anyways, brakes are done, I got the set from blauparts, and so far they are very disappointing, though i haven't been able to break them in properly due the weather, it's too slippery to do aggressive stops without the abs kicking in. but still, the initial bite is just not there.

And unrelated, does any one know about the windshield washer resevior? how difficult is it to replace, mine has a leak so low in it that i can never get rid of the low warning, it'll last about 1 day in these overly salted michigan roads.

Thanks, yet again.

Let the brakes settle in properly...front brakes, which do nearly all the stopping always feel weak at first, unless you've developed another problem.

Exremely unlikely to have a leak in the reservoir itself...more likely a hose fitting or headlight washer nozzle, connection, etc. The rerservoir is behind the rear section of the fender liner, front right wheel well.

The lowest point in the resivior is the washer pumps that are basically pushed into the resivior aided with a rubber O-ring. You will either find the O-ring is bad, or the more common problem of the washer pump casing being cracked.

The brakes will take a couple hundred miles to break in fully, even longer if you put ceramics on.

So I'll be doing mine tomorrow, I figured I'd add to this thread as we have 2 brake threads going at the moment and this one's getting more attention. I would like to hear some thoughts on rotor replacement. My car has about 160k on it, and unless Audi rotors wear amazingly quickly, they don't look like they've ever been replaced. By that I mean they've lost a little meat, but they're still flat and smooth. I have a little money at the moment and would like to see another 100k out of this car, and for an additional $130 it seems like new rotors might not be a bad deal, unless I really don't need them. I've never subscribed to the theory that you should change your rotors frequently, and I've never had to do it on other cars that I've owned for a lot of miles, so any strong opinions on pre-emptive rotor changes? (I have the 8 pad setup, and will be going to Blau to pick up the parts this afternoon)

Oh yeah - I may be a little hard on the brakes from time to time, but I'm not young anymore and I don't do any driving that's harder than my daily commute.

I look at the specified wear limit on rotors, which is just 1mm on each side...new fronts are 30mm thick and the wear limit is 28mm. If they are right at that, I use them for another set of pads...in a lot of cases, rotors are good through 2 sets of pads. I measure with a c-clamp micrometer and go from there.
Worst case is thin pads AND rotors worn past wear limit...this extends pistons beyond normal operating range and is more likely to cause caliper problems, incuding freeze-up.