Rear rotor size. Which one do I buy?

[windyctyaudi]

Ok I know the rear rotors came in 2 different sizes, how do I know which one to buy. I have a 2002 but I am assuming it has something to do with the vin # or some thing.

[Papachristou]

my audi parts dept told me there was no rhyme or reason to the sizing.. you actually have to take off your wheel and measure.. most have 245mm

[aaaudiprotein]

I think <2003 models have 245, after 2003 have 255. But still, they should be able to tell you at the parts store.

[CyberPMG]

I'm not certain about it, but I think both rotor sizes use the same caliper and carrier. Therefore, it would make sense to go for the 255mm rotor and call it a day.

Technically, the 2002 and 2003 A4 had the 245mm rotor. 2004 and 2005 A4 had the 255mm rotor.

[n7plus1]

245 for 1.8t, 255 for 3.0

[windyctyaudi]

Thanks guys im going to gamble and go for the 245 since i have an early 2002.

[aaaudiprotein]

245 for 1.8t, 255 for 3.0

No :))) Like it has been said, there is 245 till 2003.5 or so, and then 255. But it shouldnt matter overall.

[Papachristou]

i have a 2004 with a 245mm so you can throw that theory out... i believe the 3.0 thing might be more accurate(but who knows)... but you cannot use the 255mm rotor if you currently have the 245mm... i believe the carriers are different... when mine was apart, i saw that something would rub but its been awhile, dont remember where it would hit at.

http://www.ecstuning.com/stage/edpd/...productID=6149

ECS Big Brake Kit- (Cross-Drilled & Slotted/Zinc Plated Rotor, W/o Pads)
OEM 255mm rear caliper carriers & plain 255mm rear brake rotors
Convert your 245mm rear rotors to the larger 255mm rear rotors. ECS makes this simply by putting together a kit with everything you need. ECS/OEM big brake kit comes with the following components:

255mm rear cross-drilled/slotted & zinc plated rotor (2)
OEM rear caliper carrier

$309.95




Tuning Application Guide:
make model submodel engine
Audi B6 A4 All 1.8T

[aaaudiprotein]

^^^ Ok, i found :)))
Here 02 - May 04' build dates have 245's, June 04 + have the 255's

[Papachristou]

haha, mine was built 10/04 sold 1/05 and has 245... i couldnt believe that TWO dealers (memphis and little rock) told me i would have to measure, i could have either one... there must be some system because shit just cant roll off the assembly line with different sized rotors on every other car but my dealers around here dont know what planet they are on! im sure the OP will have 245mm though...

[n7plus1]

No :))) Like it has been said, there is 245 till 2003.5 or so, and then 255. But it shouldnt matter overall.

thats what mjmautohaus told me.

[Vampster]

Just my $.02...Just replaced my rear breaks and rotors and I ran into the same issue. I ordered the 245x10 from ECS, but it turned out that the caliber anchor did not fit over the rotor so I had to get a smaller one. I eventually went to the Audi dealership to get the stock one. I am not sure, but the 245 stands for the diameter of the rotor correct? If so, my rear rotors were smaller than that, if not, I don't know where I went wrong here... :-/

[pondside36]

^^^ that is really interesting... Are you sure you didn't get 255 from ECS and then needed the 245 from the dealer??? since there aren't any smaller rear rotors for our cars... hmmm

[Vampster]

Yeah! Thats the weird thing...I am sure... I have them in my car now... Thats what I thought. Here is what my packing slip said:
ES#7979
1 ECS Slotted Rotor - 9.6 (245x10) - Pair Zinc Or Cadmium Coated ES#7979


I have the rotors in my car and just checked...guess what, they mislabeled their boxes. Arghh...Just measured the rotors and they are 255s in a 245 box! Son of a @#$%. Oh well, at least I got my baby back on the road.

[gdawg'05a4]

^^^ Ok, i found :)))
Here 02 - May 04' build dates have 245's, June 04 + have the 255's

My car was built 7/22/04 ('05 model) and has 245 rears.

Still trying to figure out why some have 255s.

[Vampster]

That I dunno, unless its a cost saving solution for Audi to have 255 on both the 1.8T and the 3.0 models. Usually when you order parts in bulk you get bigger discount... :-/ only reason I see there.

[pondside36]

Oh man that sucks, so you have the ecs slotted on the front and blanks on the rear.. that sucks... I installed my slotted/dimpled on the rear the other day and still have the stock flats on the front.. but have the matching replacements to go on once the fronts go..

[Vampster]

Nope, just got the rear replaced. I actually ended up getting the OEM from Audi. Cost me $133 total for both...a tad more expensive than ECS. I really had no choice since I had my car in pieces on Saturday. I did not feel like waiting another couple of weeks so I can get the right rotors from ECS. So right now I am on stock rotors on the front and back. I will probably do a big break upgrade when I do a BT upgrade...maybe next year sometime... :-/

[FourRingsB6]

I hate to bring a thread back from the dead but did anyone figure out the correct way to tell if you have which models came with the 255's. I found a chart somewhere (that I can't seem to find now) that told me I had 255mm rears when in reality I had 245's. It sucks because I ordered 255mm rotors, received 245's by mistake and sent them back. Finally go the 255mm rotors in and I take my car today to get them put on and they don't fit. For reference I drive an 05 1.8t sedan with a build date of 10/04 and chassis code 8E5010323A. Thanks.

[actlsub9]

I hate to bring a thread back from the dead but did anyone figure out the correct way to tell if you have which models came with the 255's. I found a chart somewhere (that I can't seem to find now) that told me I had 255mm rears when in reality I had 245's. It sucks because I ordered 255mm rotors, received 245's by mistake and sent them back. Finally go the 255mm rotors in and I take my car today to get them put on and they don't fit. For reference I drive an 05 1.8t sedan with a build date of 10/04 and chassis code 8E5010323A. Thanks.

Check the part number on your stock rotor.

8E0 615 601 P = 245x10mm
8E0 615 601 D = 255x12mm

[FourRingsB6]

Thank you

[Papachristou]

I hate to bring a thread back from the dead but did anyone figure out the correct way to tell if you have which models came with the 255's. I found a chart somewhere (that I can't seem to find now) that told me I had 255mm rears when in reality I had 245's. It sucks because I ordered 255mm rotors, received 245's by mistake and sent them back. Finally go the 255mm rotors in and I take my car today to get them put on and they don't fit. For reference I drive an 05 1.8t sedan with a build date of 10/04 and chassis code 8E5010323A. Thanks.

yes, the best way to be sure is to take off your tire and measure!

[fla4sline]

Brake code should be on your white VIN label. 1KD is 245mm. 1KP is 255mm. White label can be in your Audi warranty book or in the trunk by the spare tire.

[msharifi]

Ok I know the rear rotors came in 2 different sizes, how do I know which one to buy. I have a 2002 but I am assuming it has something to do with the vin # or some thing.

From what Audi told me if its a 1.8t the rears are 245 and the 3.0 rear is 255

[aaaudiprotein]

From what Audi told me if its a 1.8t the rears are 245 and the 3.0 rear is 255

latere models 1.8ts had 255's. thats why OP asked this question

[quiljw01]

FYI - I am in the middle of replacing my rear rotors and just found out about this mess. I had no idea there were 2 sizes when ordering my rotors. I went to install them last night and found that the new rotor doesn't fit because it runs into the caliper bracket - so i need 245mm diameter rotors, not 255. I have an '04 1.8t sedan. I hope Amazon.com will return these without a fuss.

I think it would be worth either measuring first, OR if its easy enough, just buy both sizes and return the ones you don't need. (you can't measure with a ruler or tape while the rotor is on so you'll either have to remove the caliper+bracket+rotor so you can measure on the back of the rotor, or measure with a different tool like calipers) i haven't checked my white VIN label so i can't confirm thats true for me.

[Outerfroggy1]

Brake code should be on your white VIN label. 1KD is 245mm. 1KP is 255mm. White label can be in your Audi warranty book or in the trunk by the spare tire.

Thanks for the info!

[Stockton]

Brake code should be on your white VIN label. 1KD is 245mm. 1KP is 255mm. White label can be in your Audi warranty book or in the trunk by the spare tire.

Is this the only way to tell without measuring. I can't seem to find that brake vin anywhere...

I need new rear brakes badly and I want to just order them now from ECS but don't have the ability to take my wheel off and measure till next weekend. I'm hoping to have the brakes by then though and just replace but want to make sure I get the right size.

Edit: Found the sticker in the trunk wheel well. I have 1KD so I guess I'll be ordering the 245mm for the rears.


I do have a question about fluid. If I were to drain the fluid, how much do I need to replace it all so I'm not stuck with half full brake lines.

[Alex_Mk3]

hate to bump this again but where i didnt find anything by the spare tire. i have a 04 avant. made 08/03. im too lazy to take wheel off to measure

[EBG 18T]

hate to bump this again but where i didnt find anything by the spare tire. i have a 04 avant. made 08/03. im too lazy to take wheel off to measure

You can always call Audi parts dept with your vin #. They should be able to cross reference.

[n7plus1]

im assuming the carriers are a bit larger for teh 255 rotors?

[swizzchard]

Bumping this thread because I did what people suggested - call the dealer... and my local dealer, Len Stoler Audi in Maryland is a PoS "I can't give you a part #. It's our company policy"...dick

He did tell me the option code which is 1 KD for a 2005 A4 Ultrasport Avant

[EBG 18T]

Bumping this thread because I did what people suggested - call the dealer... and my local dealer, Len Stoler Audi in Maryland is a PoS "I can't give you a part #. It's our company policy"...dick

He did tell me the option code which is 1 KD for a 2005 A4 Ultrasport Avant

Wow. Bunch of parts deptment dicks

[imnuts]

Wow. Bunch of parts deptment dicks

x2. I would call a different dealer. Or if one is close to you, go in, ask to see the part to make sure it is the same and just write down the number off of it and leave without buying.

[Petabell]

Check the part number on your stock rotor.

8E0 615 601 P = 245x10mm
8E0 615 601 D = 255x12mm

What does is mean if my rear stock rotor says: 8EO 615 601 B?