A6 brake-bleeding headache...

[Biohazard457]

I had to replace the front-right brake caliper a few months ago after it failed while my mom was driving the car. Fast-forward to today, and the front-right and rear-left calipers will not bleed for anything. I understand the caliper I replaced being fickle, but the rear driver-side caliper wasn't touched at all until I went to bleed the system. I've tried power bleeding, vacuum bleeding, buddy pumping the pedal for hours bleeding, ABS bleeding through the car's computer, replaced the master cylinder... and there is absolutely no brake fluid going to the two mentioned calipers. The pedal stays soft all the way to the floor and rises back to the top very slowly. the front-left and rear-right calipers have fluid flowing with no air bubbles. It isn't a huge rush to get the car back on the road, but I would really like to get the problem resolved within the next month or so.

[glennda5id]

If fluid does not flow to the caliper via gravity you have a blockage.

[Calif_Kid]

I had to replace the front-right brake caliper a few months ago after it failed while my mom was driving the car. Fast-forward to today, and the front-right and rear-left calipers will not bleed for anything. I understand the caliper I replaced being fickle, but the rear driver-side caliper wasn't touched at all until I went to bleed the system. I've tried power bleeding, vacuum bleeding, buddy pumping the pedal for hours bleeding, ABS bleeding through the car's computer, replaced the master cylinder... and there is absolutely no brake fluid going to the two mentioned calipers. The pedal stays soft all the way to the floor and rises back to the top very slowly. the front-left and rear-right calipers have fluid flowing with no air bubbles. It isn't a huge rush to get the car back on the road, but I would really like to get the problem resolved within the next month or so.

If you almost completely or even take off the bleeder screw out of the front-right or rear-left calipers, do you get any brake fluid coming out? What I'm getting at, is maybe the bleeders are somehow clogged internally, so no fluid can get thru them even after the bleeder is partially loosened and the brake pedal is pressed.

As far as the pedal being very soft, it sounds like there is air left in the system, but that is why you're trying to bleed the system. On my 2000 Ford F150, I had problems where the brake pedal being soft no matter how much I bled the system - I was using a brake bleeder bottle like https://www.amazon.com/Motive-Produc...bleeder+bottle with the bottle somewhat above the bleeder and some brake fluid covering the bottom of the bottle, so I would just open the bleeder somewhat with the bottle connected, and then go inside the car and it would pump out the fluid and any bubbles. Anyway, as I just couldn't get the pedal to be hard, I finally figured out that the threads around the bleeder screws on the front brakes were a loose enough fit that air was getting sucked back in using my bleeding method. I removed the bleeder screws, wrapped a little Teflon tape around them, and the brakes then bled great. Afterward, I was looking in Autozone, and noticed that some of the Speed Bleeders also have some Teflon or sealer on the threads.

One other thing - I've seen write ups about activating the ABS system using Vag.com to the left front wheel, so if there is some air left in the ABS, then that may help the soft pedal. One thing that I don't like on the Audi's is that the screen is a pain to get off of the master cylinder. For your problem, even if the calipers you're having problems with are completely frozen, then it seems like you should still be able to get fluid coming out of them. - Jim

[Iamdoinitrite]

Thread Jack incoming:
Anyone have any recommendations for replacement Rotors/Brakes? Not looking to upgrade, just get rid of my warped rotors and throw on some new pads with em for a reasonable price. I believe I need 8 pads (4 per side), and 2 321mm (I believe) rotors. All for the front.