You may need a rear disc brake caliper tool for your car. See the link below to see what it is C-clamps also work but you have to be careful to squeeze the caliper straight in. Take your time.
a special scanner called a v.a.g. has to be used to retract the electronic e brake system, and will also retract caliper piston..DO NOT TRY WITH OUT TOOL !!!!!
Could be the brake caliper or the CV joint going.
They need to be wound back in, using a special tool, a G-clamp also work to push it back, with the rotating part on the caliper piston.
I believe on this model you need a special tool to push the piston back. You can go to the website I have below click the link below!
dissconnect the handbrake cable, remove the flexi brake pipe, remove the 2, 13mm bolts from the sliders and take off the caliper. when fitting the new one you must wind back the piston back as far as it will go.put in your brke pads fit your caliper tighten up your 2 13mm bolts fit pipe and hbrake cable and bleed the system,
the front compress with a clamp. the rear caliper pistons need to be pushed and turned at the same time. * yes put something flat against the plunger then slowly tighten c clamp until completely depressed * no the answer above is wrong, you gotta turn the plunger with a special tool. The rear calipers have to be turned as you push them in. It is a big allenkey that you will need. I put a c clamp on the side of the piston so that i could push it in a bit, then turn, then push some more. This takes patience but it works. Or just go to a small VW/Audi garage and ask to borrow the tool.
DOT 4. Is the recommended brake fluid by Audi.
Replace the brake pads.
The brake light in the Audi A4 display means there is an issue with the brake system. The most common cause of this warning light is low brake fluid.
Answer to loose caliperA. First, make sure you have the correct bolts. Buy new ones from dealer or take a trip to your local recycler or used Audi parts on the internet if you are unsure. B. Remove brake carrier from the wheel bearing housing (if this is what you can't tighten) and rotor to be sure you can gain direct access to the brake carrier mounting bolts. Acquire the correct metric tap, probably 5 or 6 mm, you maintenance manual may give you a clue, then use the tape to clean out the threads in the brake carrier mounting holes in the wheel bearing housing which is the lower part of the strut. That should take care of the brake carrier mounting bracket to which the caliper mounts and brake pads mount.C. Now, if you are talking about the mounting of the caliper to the brake carrier being loose, then that's a horse of an entirely different color. The caliper "floats" laterally to allow the caliper to function properly and at the same time compensate for brake pad wear. There are "guide pins" in the brake carrier to which the caliper mounts. These pins with their rubber boots are what allows or provides for the lateral movement of the caliper. Before you bolt on the caliper, make sure these guide pins move in and out of the brake carrier freely but are not so loose that they have excess play from side to side. If they don't move freely, carefully remove the rubber boots and pull the pins all the way out to clean them and their channel in the brake carrier. Now lubricate the pins with a very good heat resistent grease (I like silicon grease here), reinsert them back into the brake carrier, and now reinstall the rubber boots. It is because of these rubber boots that I like the silicon grease. Now you are ready to reinstall the caliper on the newly refurbished carrier channels and guide pins. Obviouisly, if there is a lot of "play" in the guide pins, you may have to replace the guide pins and/or the brake carrier. If you found rust when you took the boots off, there is more than an even chance that the guide pin channel channel in the brake carrier is ruined and the brake carrier and the guide pins need be replaced.There, now you are an Audi brake expert. :-)
As of 2014, the cost for a Audi A4 brake light is between 12 and 15 dollars. This light can be purchased at stores like Auto Zone.