Rear brakes and rotors replacement

**B8SlineNate** · 02-07-2015 01:27 AM

So I did a little search but did not find a real answer regarding the rear brake pads and rotors replacement. Will the rear require VCDS to electronically retract piston or can I do it manually the old fashion way with a piston retractor tool? Thanks!

**eirebob** · 02-07-2015 12:12 PM

There's a broad range of opinions about the need for the VCDS protocol in preparing to retract the rear caliper pistons. You'll still need the piston retracter tool regardless.

I'm up in Santa Rosa, and have the Ross Tech cable if you feel you need to heed the protocol (and I would recommend it). Post this thread in the Norcal regional section to find someone else nearer if you're not close by the North Bay.

**jfo** · 02-07-2015 12:57 PM

If you use VCDS to retract the pistons, a retracting tool is not needed. You will find posts where people have successfully retracted the pistons and completed the job using only a retracting tool. However, others have commented on the potential for damage to the control module when retracting the pistons manually. So, it seems it is indeed possible, but you might be taking an expensive risk. I have never seen a definitive official answer to the question of possible damage. Since I have the cable, I used it when recently replacing my rear pads and rotors.

**booost** · 02-08-2015 11:04 AM

I needed to open the rear calipers a bit more with a retractor after opening them with VCDS.

**jfo** · 02-08-2015 02:07 PM

Originally Posted by booost

I needed to open the rear calipers a bit more with a retractor after opening them with VCDS.

I believe you can push the piston back manually with a screwdriver or clamp after VCDS has done it's retraction, similar to the front caliper. The Ross Tech video shows this and if I recall, I did this when working on mine. No special tool needed.

**Whyu1nunno** · 02-09-2015 02:09 PM

Hey for one time use, could we use this? I have this same job coming up this weekend...

http://www.ebay.com/itm/VAG-COM-USB-..._Tools&vxp=mtr

If not would this work?

http://www.ebay.com/itm/Ross-Tech-He..._Tools&vxp=mtr

**elscotto80** · 02-09-2015 04:40 PM

Buy the real deal. The knockoffs sometimes dont support all functions that the full VCDS does. And its nice to support a company thats actually doing really good work for our cars, not some douche in Asia.

**Whyu1nunno** · 02-09-2015 09:13 PM

I understand the sentiment however for a one time use, one function one application Im just asking if it would work yes or no. I mean. One of those listings has like 300 sold (and there's like 15 listings) so someone has to know if it works or not. There's a big difference between spending $10 and $300 especially if the $10 works for what I'm looking to accomplish which is changing the rear brakes and nothing more. That other $290 can go to my new steering wheel fund lol

**jfo** · 02-09-2015 10:06 PM

The knock off may work...or it may not. There are many posts about both experiences with the various pirated versions. All you can do is try one and see.

**elscotto80** · 02-10-2015 05:37 AM

So you plan to replace your steering wheel as well? I bet you are going to need to do some coding with that, requiring vcds. The tool is very useful and can do lots of things. I wouldn't look at it is just using it for just the brakes. It can do quite a bit.

**booost** · 02-10-2015 07:43 AM

When I did my brakes I closed the calipers with VCDS after I was done changing the pads/rotors. The ebay cables will work but as stated they are hit or miss.

**Whyu1nunno** · 02-10-2015 10:35 AM

ok that all sounds reasonable enough. I'll look into it to see what else can be done.

Re: the steering wheel it does require slight rewiring (changing stock for TTS wheel so need to switch connectors and create a second ground, etc) but no coding is necessary from my research.

Originally Posted by booost

When I did my brakes I closed the calipers with VCDS after I was done changing the pads/rotors. The ebay cables will work but as stated they are hit or miss.

So you didn't need it to open them? Man there is so little literature on how to DIY these brakes. I've heard:

1) cable needed. Would be stupid to not use it
2) use a retractor tool, no cable needed at all. Maybe lol.
3) take the plug off of the ebrake and connect a 12v battery to operate the ebrake manually

i'll keep researching. Brakes came in today and the weather is good so i might change at least the fronts today. My mechanic says he can do the rears as long as i can operate the rears so we'll see how that goes.

**booost** · 02-11-2015 06:22 AM

I opened them with VCDS, then had to open even more with a retractor. I closed them with VCDS when I was done. I read on the Ross Tech guide about hooking up an aux battery when doing the install but I didn't do it and had no issues.

**Whyu1nunno** · 03-02-2015 07:33 AM

Ok so i FINALLY got around to changing my brakes this weekend. it took some time because i had a stripped lugnut that i had to twist off with a lugnut remover and also a stripped Rotor screw on the passenger rear side (i used a dremel to grind the head of the screw off and the rotor came off like butter.... vice grips to take the stud out.... bought a new stud....... just like newww)

Originally Posted by booost

I opened them with VCDS, then had to open even more with a retractor. I closed them with VCDS when I was done. I read on the Ross Tech guide about hooking up an aux battery when doing the install but I didn't do it and had no issues.

+1 here. I ended up getting an XTool instead of the Ross Tech cable (costs $70 on Amazon and doesn't require a computer) and was abe to complete the job exactly as booost. Front brakes are childs play, and so are the rears once you release the brake. However i had to use a C-Clamp to fully retract the piston to fit over the new brake pads. Afterwards used the XTool to reset the e brake. too easy.

Took her for some hard driving in the snow and these brakes are fantasticccccccc. Stop Tech plays 0 games. now... on to that steering wheel....

**burbs9** · 03-04-2015 09:58 PM

Originally Posted by jfo

... Since I have the cable, I used it when recently replacing my rear pads and rotors.

I noticed in the Ross-Tech video, they connected a battery charger to the battery during this procedure. Is that part necessary?

**jfo** · 03-04-2015 10:12 PM

I believe it's a safety precaution to protect the electronic module. I'm not sure, but I think the idea is to avoid the possibility of the battery going dead while you have the ignition on and Vagcom connected/running while you perform the repair.

**A4BGP** · 03-05-2015 04:57 AM

Not so much going dead but falling below a voltage threshold. The TRW module quits below a certain voltage and is apparently damaged in the process. The actuators will run for fairly a short period but it's a good precaution to take.

**MadhatterPDC** · 04-27-2015 11:09 AM

This weekend, I replaced the pads on all four corners of my wife's 2011 Q5, and have a couple questions.... I am posting here as the brake systems are exactly the same as the B8 A4 and this sub-forum is much more active than the Q5 sub-forum.

The problem is, now the pedal feels lower than before. It doesn't feel like a leak, the pedal is not sinking at all. When I did the rears, I used a VCDS cable and followed the instructions on Ross-Tech to "open" the rear calipers, then used a pad spreader to open the caliper the remaining distance. The parking brake seems to be working correctly and will hold the car on the steeper portion of my driveway. Has anybody else had a "low" pedal after changing only the pads?

Open Rear Parking Brake
Prerequisites:
Connect a battery charger as per repair manual.
Cycle the Parking Brake ON, then OFF first.
[Select]
[53 - Parking Brake]
[Basic Settings - 04]
Group 007
[Go!]
The brake calipers will then open, allowing the pads to be changed.
[Done, Go Back]
[Close Controller, Go Back - 06]
Turn ignition off.

It is normal for the LED in the parking brake switch and the warning lamp in the instrument cluster to blink rapidly at this point.

The caliper pistons do not move back into the caliper, this is normal.

Close Rear Parking Brake
Prerequisites:
Connect a battery charger as per repair manual.
[Select]
[53 - Parking Brake]
[Basic Settings - 04]
Group 006
[Go!]
The brake calipers will then close.
[Done, Go Back]
[Close Controller, Go Back - 06]

**MadhatterPDC** · 04-27-2015 11:21 AM

https://www.youtube.com/watch?v=cHJMI4QkSy8

I just re-watched the Ross-tech video at the link above, and it mentions pumping the brakes back up before VCDS "closing" the calipers. I'm pretty sure I electronically "closed" the calipers BEFORE pumping the brakes up. I'm hoping that I can use VCDS to "open" the calipers, then pump, then "close". Unless someone knows of a reason why I should not do that?

**STA4** · 08-11-2015 12:49 PM

Did any of you buy new fasteners or did you simply reuse? I believe the caliper bolts are self-locking and aren't supposed to be reused. Can we simply apply some loctite?

Did anyone clean and lube the slider/guide pins?

**domamei** · 08-24-2015 07:14 PM

Originally Posted by booost

I opened them with VCDS, then had to open even more with a retractor. I closed them with VCDS when I was done. I read on the Ross Tech guide about hooking up an aux battery when doing the install but I didn't do it and had no issues.

Just changed my rear brake pads and had to do the same thing. After using VCDS to retract the piston, it wasn't enough. Went to autozone and rented the piston retracting tool. And had a friend help twist the piston a little more in. Other than that the job wasn't that bad. Took about 2.5 hours for my first time doing the rear brakes on an Audi pausing to go to the autoparts store. Thanks for the DIY guys! This helped out.

**STA4** · 08-25-2015 08:20 AM

Originally Posted by domamei

Just changed my rear brake pads and had to do the same thing. After using VCDS to retract the piston, it wasn't enough. Went to autozone and rented the piston retracting tool. And had a friend help twist the piston a little more in. Other than that the job wasn't that bad. Took about 2.5 hours for my first time doing the rear brakes on an Audi pausing to go to the autoparts store. Thanks for the DIY guys! This helped out.

Which type of tool did you use? I'm still confused about whether the piston has be screwed back or if you can simply push back after using VCDS.

**domamei** · 08-25-2015 09:31 AM

Originally Posted by STA4

Which type of tool did you use? I'm still confused about whether the piston has be screwed back or if you can simply push back after using VCDS.

I used the single pronged one on the left. With VCDS the piston is retracted in but not enough for me to fit the caliper back on. You can rent it at autozone and return it to get your money back.

**jfo** · 08-25-2015 10:10 AM

Originally Posted by STA4

Which type of tool did you use? I'm still confused about whether the piston has be screwed back or if you can simply push back after using VCDS.

After you have retracted with VCDS you can you can push the piston in further with a C clamp or large channel lock pliers. At this point you don't need to screw it in.

**STA4** · 08-25-2015 10:22 AM

Originally Posted by jfo

After you have retracted with VCDS you can you can push the piston in further with a C clamp or large channel lock pliers. At this point you don't need to screw it in.

Much appreciated. I'd rather not have to find a tool kit (we don't have Autozone up here in Canada).

**STA4** · 10-28-2015 02:46 PM

Originally Posted by jfo

After you have retracted with VCDS you can you can push the piston in further with a C clamp or large channel lock pliers. At this point you don't need to screw it in.

Further to this, I attempted this over the weekend and indeed a special tool is not required...not even a C clamp. With the caliper still on, simply insert a flathead screwdriver in the window on the caliper (through which you can see the rotor sandwiched by the pads) and pry between the caliper and the back of the outer brake pad and the piston will retract. This method is shown in the ROSSTECH VCDS EPB video mentioned above.

I ended up not being able to remove the caliper carrier bolts, so I'm going to bring the car to a shop and have them change the rear brakes.

**Townending** · 12-28-2015 11:27 AM

Originally Posted by STA4

I ended up not being able to remove the caliper carrier bolts, so I'm going to bring the car to a shop and have them change the rear brakes.

Same here, anybody have any tips for removing these? I was able to get my breaker bar in there, but had no room to move/use it once it was on.

Wondering if I should buy an impact gun, or pay a shop to do it. My biggest concern with an electric impact gun would be the size, not too sure if they would fit freely near the suspension.

**blbroo** · 12-28-2015 11:40 AM

Originally Posted by Townending

Same here, anybody have any tips for removing these? I was able to get my breaker bar in there, but had no room to move/use it once it was on.

Wondering if I should buy an impact gun, or pay a shop to do it. My biggest concern with an electric impact gun would be the size, not too sure if they would fit freely near the suspension.

Did you try to hit them with some PB blaster? I had to use a breaker bar too, and remember it being weird angles to make it fit. You might have to jack up the axle some to get a different shot at it.

**Townending** · 12-28-2015 11:45 AM

Haven't tried PB blaster yet, I'll start spraying that every other day so I can try again this weekend.

**B8SlineNate** · 12-31-2015 01:42 AM

Thanks to everyone's input I finally completed this task today. Pretty straight forward.

**Westija** · 12-31-2015 06:01 AM

Whyu1nunno, would you please let me know which Xtool you purchased for this? I did some research on Amazon and tge one I saw did not have the B8 as one of the models supported for the rear caliber retracting operation. I then sent them an email and was told that it would not work for this model.
Much appreciated.

**STA4** · 01-04-2016 11:18 AM

Originally Posted by Westija

Whyu1nunno, would you please let me know which Xtool you purchased for this? I did some research on Amazon and tge one I saw did not have the B8 as one of the models supported for the rear caliber retracting operation. I then sent them an email and was told that it would not work for this model.
Much appreciated.

You don't need a tool. Just pry with a screwdriver (after releasing with VCDS).

**shaunm82** · 01-04-2016 11:44 AM

Originally Posted by Westija

Whyu1nunno, would you please let me know which Xtool you purchased for this? I did some research on Amazon and tge one I saw did not have the B8 as one of the models supported for the rear caliber retracting operation. I then sent them an email and was told that it would not work for this model.
Much appreciated.

Ditto to the no tool needed.

Though I do have one of these, and it would work just fine if you want to push it in a little more after you release with VCDS:

http://www.amazon.com/Lisle-24400-Di...s=caliper+tool

**Westija** · 01-06-2016 08:57 AM

Gents,
Pls see above. The tool he used was one to retract the pistons since he did not have VCDS/Ross Tech.
So I am not referring to further retracting the caliper but what XTool was used instead of VCDS to get to that point
Thanks

**miyagi** · 02-01-2016 03:19 PM

For those with an Electronic rear park-brake, like me, I can tell you from experience that you DO NOT need any VCDS software or VAG cable, nor do you need to take it to a specialist.

all you need is a $10 caliper tool spreader, a spare car battery, a couple wires and then watch this vid:

https://m.youtube.com/watch?v=J-q68JIUils

I was able to change both rear e-brakes last weekend just by following this video - and it saved me hundreds of dollars.

NOTE: make sure your e-park brake is turned off before you commence

**bobdini** · 02-03-2016 06:13 PM

just replaced my front and rear rotors and pads. First you need to open the parking break with a vag or the old fashioned way with batt and wire. Than the caliper piston needs to be twisted in and spread with a caliper tool or c clamp. it was a pain the first time i did it on my B8 A4.

**Westija** · 02-05-2016 06:37 AM

Miyagi,

Thanks for the video, seems simple enough to me.

I will try it soon. I've done the two fronts already, so rears are the next step.

**beckmaster** · 02-09-2016 10:00 AM

Just out of curiosity, why do we need to connect a battery charger? What happens if we don't?

**miyagi** · 02-11-2016 02:53 AM

Originally Posted by Westija

Miyagi,
Thanks for the video, seems simple enough to me.

I will try it soon. I've done the two fronts already, so rears are the next step.

no probs, hope it helps you as much as it did me

Originally Posted by beckmaster

Just out of curiosity, why do we need to connect a battery charger? What happens if we don't?

you need to connect a car battery in order to run the e-brakes and make it disengage from the disc/rotors - you need to do this in order to get the brake pads off the calipers - the break spreader will not be able to do this alone

cheers