Lewbuu76

Purchased a 2000 Audi A6 Quattro with The 2.7 Twin turbo engine. i went to change my rear brakes called Audi to get the part number for the rear brakes system got the pads and the rotors went to put them on my vehicle and the pads fit but the rotors touched the front face of the caliper brackets on both sides so i did a bit of research and found that there are 3 different rotors for my vehicle the difference being the had size so i measured the hat size of the ones that i had just bought 1.5" so i bought the 1.75" hat rotor thinking that maybe i was given the wrong rotors. so i received the new rotors and when i put them on i found that they no longer touched the front of the bracket but now touch the rear of the bracket so then i thought that maybe it was the bracket and so i replaced the brackets and same issue i'm running out of ideas any help would be greatly appreciated

Harleyguy

The original rotors should have the part number stamped or cast into the metal. Usually on the outward face of the "hat". This should be the part number to use for replacement. Are you sure that the brakes haven't been modified, like maybe performance brake parts (Brembo, etc.)? Also see if you can find part number on calipers as this may give you a clue as to what rotors are needed. Yes there are several options when it comes to Audi brake parts. If you have a digital micrometer to measure the hat height, it probably has a built in conversion switch to read millimeters. It is sounding like changes have been made to original equipment. If you go aftermarket and provide VIN # it may not narrow the options down to a single item. Also an after thought. Make sure the caliper pins are free and allowing the caliper to float over it's full range of travel.

Lewbuu

i have used the part number off of the original rotors that were on it when i got the vehicle and it matched up with the part that Audi gave me after running my vin number i have tried a couple different brands for this number (audi, brembo, autozone,) and same issue and i have put new caliper brackets on with the same issue the even before i put the caliper back on you can see that the rotors touch the bracket. and i called audi trying to see if the caliper is different between the different sizes and was told that it is the same caliper for the 3 different brake options

georgeb944

I have owned 4 A6 C5 cars with 2.7T motors, and all have had the same rear rotors.

The part number I have ordered is 4B0615601B ... I have used the Meyle, ATE, and Bosch brands without problem.

Harleyguy

Another item that is often missed is cleaning up the hub before mounting the replacement rotors. The previous owner of my car overlooked this part of the work and ruined brand new rotors and pads (on the front) in about 6k miles. All rust and debris (grease, road grime, brake dust, etc) needs to be removed before installing new parts. Something must be out of position if none of your described remedies are working. Can you post a couple of photos for us?

Lewbuu

i will try to post take a couple tomorrow before work

Lewbuu

that is the part number of the rotors that i was given and had come off the vehicle to begin with

Harleyguy

Using that # on ECS Tuning site search shows multiple listings all indicating 255mmX10mm with 1.50 inch offset. If that rotor isn't fitting then something else is amiss. Either modifications have been made to the mounting or something else is restricting clearance, such as debris build-up, rust, or calipers are not fully retracting. Is the piston fully retracting into the cylinder on the caliper? Not sure how much experience you have so please excuse the following question. Are you aware that the rear brakes require that the piston be screwed in while being compressed back into the cylinder on the caliper? Again my apologies but inexperienced people sometimes aren't aware of this.

SloopJohnB@mac.com

If you match the OEM rotor with the new rotor you bought you could be sure you have the right rotor.
If the new rotor physically matches the original rotor, you've done something else wrong.
Just asking, can you put the old rotor back on and it fits?

If so, Get. The. Matching. Rotor.