Brake bleed after caliper change. Can't get a good pedal feel.

[LoloHaole]

I swapped in some C7 A6 6 piston front calipers and ECS brake lines and after bleeding first with a Motive pressure bleeder, then with the pedal method, I still have a mushy pedal.

I think I messed up when doing the pedal method and let the reservior get too low, introducing more air into the system. (UGH!)

I've been bleeding with the pedal method, both with the car on and off. When the car is running, I was getting air out of the lines every time I cracked them open. Tiny little bubbles that are barely visible, but I can hear the bubbles "woosh" when I crack open the bleeder.

I eventually got it to where no air was coming out of the bleeders, but my pedal still feels like mush.

Research is showing me that I should do the ABS pump bleed procedure in Vag-Com.

Questions:

After I do the ABS pump bleed, what is the correct caliper bleed sequence? I've been doing Rear Right, Rear Left, Front Right, Front Left.

Can I hook up my Motive pressure bleeder AND do the ABS pump procedure?

Can I also hook it up for doing the pedal pump method to ensure that my master cylinder stays full and I don't have to keep refilling it?

My new front calipers have 2 bleed screws. I've been alternating opening them and getting air out of each one in alternation. Good idea to continue that?

What else do I need to do?

I've read a dozen threads that all have different suggestions, many of which are for different Audi / VW models and years, so I'm confused at this point. All help is welcome!

Thanks,
LH

[Audi_Jer]

I'm not sure about the whole ABS procedure, but you should be bleeding with the car off. I've done my brakes 3 times, and helped others, and never once had the car on the bleed. It feels very mechanically difficult to push the pedal, but it should. I've always read you don't need/want the power vacuum assist to bleed.

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[LoloHaole]

With the car off, no air bubbles come out when bleeding. I think some air is in the ABS or somewhere else, which may be why I get tiny air bubbles when bleeding with the car running. I don't know...

I'm going to try this tomorrow, then do a bleed with the car off:

ABS pump bleed procedure in VAG-COM:
[Select]
[03 - ABS Brakes]
[Basic Settings - 04]
Group 001
[Go!]

Once you hit GO! the screen says to depress pedal and hold
You have to press the pedal HARD. Seriously, pound the pedal like you're about to drive over a cliff. Remember to hold the pedal down!

The pedal will drop, the pump runs briefly, then the pedal comes back up.

Take your foot off the pedal.

I think it wants you to click on OK at this point.

The screen says something like FR/FL bleed screw OPEN.

Open both front bleed screws. Obviously, on each bleed screw you'll have some tubing going from the bleeder into a catch jar.

Click on OK (or DONE or something like that).

Pump runs for 10 seconds, pushing fluid out of the bleeders into your catch jars.

Screen says something like: Depr. pedal 10X; bleed screw CLOSED

Depress pedal firmly 10 times, then close both bleed screws.

Click OK.

You'll get sent back to the depress pedal and hold screen and repeat the cycle. It goes on for like 10 or 15 cycles. I never got a finished message, I just did it until the screen said N/A.

It is easier with two people. One in the car pressing the pedal and working Vag-Com, the other outside opening and closing bleeders and making sure the master cylinder doesn't run dry (very important!).
If you're doing this solo, put the laptop on the driver's side roof so you can access it easier. It's also a great workout as you run in and out and around the car.
After the ABS pump is bled, you can then bleed the rest of the system as normal.

[LoloHaole]

I can't get the ABS system to pump via VCDS. When I go into the ABS module, I get an ECS error on my center screen of the car. I looked up the error I was getting and found it was related to having DSR disabled, so I enabled it, turned everything off and back on, went into ABS again but still get the ECS error, and a different error about system test activated.

When I click "GO!" on group 001, I get the error Group 001 not available.

Can anyone help? This is insanely frustrating!!

Error below:

Tuesday,21,July,2020,16:54:38:29712
VCDS Version: Release 20.4.1 (x64) Running on Windows 10 x64
www.Ross-Tech.com

Address 03: ABS Brakes Labels: 8K0-907-379-V1.clb
Control Module Part Number: 8K0 907 379 CK HW: 8K0 907 379 CK
Component and/or Version: ESP8 quattro H09 0100
Software Coding: 291D1A
Work Shop Code: WSC 06324 000 00000
VCID: 0451891D9E1C5E2B773-8050
1 Fault Found:

01486 - System Function Test Activated
000 - -
Freeze Frame:
Fault Status: 01100000
Fault Priority: 4
Fault Frequency: 1
Reset counter: 166
Mileage: 108618 km
Time Indication: 0
Date: 2020.07.21
Time: 16:37:18

Freeze Frame:
Hex Value: 0x0000
Hex Value: 0x4702
Hex Value: 0x0019
Hex Value: 0x31A8
Hex Value: 0x0000

[LoloHaole]

It looks like VCDS simply can't access this function. Well, this guy couldn't get into it either with a tourag, but he did bleed his ABS with the car running, which is what it looks like I'll have to keep doing. I wasted an hour or more trying to get VCDS to activate the ABS pump.
https://www.clubtouareg.com/threads/...9/post-2072148

I'm going to try pedal bleeding with my motive bleeder hooked up at a moderate pressure so that it keeps adding fluid as I bleed the calipers. I haven't read anything about doing it that way, so if anyone knows why that's a bad idea, please tell me!

[LoloHaole]

Also, does anyone know if this caliper bleeding order a tourang thing? I've been doing RR, RL, FR, FL
https://www.clubtouareg.com/threads/...9/post-2066421

Open the bleeder valves in the specified sequence and bleed
the brake calipers.
1- Left front brake caliper
2- Right front brake caliper
3- Right rear brake caliper
4- Left rear brake caliper

[Audi_Jer]

That's a weird bleed order. I've always seen it basically bleeding from the farthest away caliper working to the closest, as you have been doing.

Sorry about the ABS thing. That's a real pain. I wish I could offer help. Have you checked the Ross-Tech forum?

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[U_know_me]

I’m in the same boat, did Macan calipers over the weekend. Bled twice. First the Audi recommended way, and second the furthest way. Still very mushy. Planning to bleed again tonight. Someone suggested using a rubber mallet to hit the calipers so extra air will come out, I am going to give it a try.

I will let you know how it goes.


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[LoloHaole]

Audi_Jer: I contacted Ross-Tech via email and they sent me a link to an ESP system function test. Not what I need, which I let them know.


U_Know_me: Which way was the Audi recommended one? I swear I've read every possible combination of bleeding orders as being the recommended one by this point, but also reading about a lot of different models.

I still haven't seen anyone pedal bleeding with the motive bleeder attached at a moderate PSI in order to keep fluid going into the master cylinder. I'm going to try it today unless someone tells me it's a terrible idea that will break something.

[hardfive]

Audi_Jer: I contacted Ross-Tech via email and they sent me a link to an ESP system function test. Not what I need, which I let them know.


U_Know_me: Which way was the Audi recommended one? I swear I've read every possible combination of bleeding orders as being the recommended one by this point, but also reading about a lot of different models.

I still haven't seen anyone pedal bleeding with the motive bleeder attached at a moderate PSI in order to keep fluid going into the master cylinder. I'm going to try it today unless someone tells me it's a terrible idea that will break something.

I use the motive and the VCDS abs test and someone pressing the brake pedal all at the same time. No issues.

I don't actually fill the motive though as its a pain to clean. I just fill the brake fluid res 100% and pressurize it then bleed one caliper. You wont pull enough fluid if you are careful and though its a little more work to keep refilling the reservoir, I don't have to clean my brake bleeder at all and risk the brake fluid damaging the seals and causing me issues down the line.

Just read the other day Audi on the a4 says to pressure bleed at 2 bars pressure (about 29 psi) which likely explains why doing it at 16psi has had me doing multiple rounds. Assuming brakes on a4 and s4 are the same as they are basically all the same components.

After I do the ABS pump bleed, what is the correct caliper bleed sequence? I've been doing Rear Right, Rear Left, Front Right, Front Left. Yeah thats kinda the classic standard. Audi does say to start with theleft front order thats above. Ive done both, cant say I believe it matters too much.

Can I hook up my Motive pressure bleeder AND do the ABS pump procedure? Yes. Actually much better.

Can I also hook it up for doing the pedal pump method to ensure that my master cylinder stays full and I don't have to keep refilling it? Yes. I've literally done all 3 at once (motive/VCDS abs/Pumping).

My new front calipers have 2 bleed screws. I've been alternating opening them and getting air out of each one in alternation. Good idea to continue that? Yeah. Back and forth. Once your brakes are safe to drive on, even if a bit mushy. Drive around the block, this will also get the air moving and bubbles trapped at the bleed screws that you can then get out.

ABS test really is your friend here, definitely want to get that figured out.

[LoloHaole]

Thanks, hardfive! Good info. How are you running the ABS test? I'll buy another tool if I need to.

[LoloHaole]

Update: After an hour or so of bleeding with my super patient GF pumping the brakes, probably 6 or so rounds of bleeding, I have a decent pedal feel. Not amazing, but decent.

I put 2 quarts of Pentosin into the Motive pressure bleeder, filled the line with fluid with just enough pressure to get it moving, covered the hole in the cap with my thumb and put it onto the reservoir as fast as I could to minimize air in the line. I kept the line elevated to hold the air pocket that formed. I added a little pressure, not too much, and just pumped the handle a couple times every 2 calipers. It really saved a LOT of time not having to refill the res every 1-2 calipers.

I also put a small piece of 2x4 under the brake pedal to keep it from traveling too far (thanks, internet).

I bled in a variety of caliper orders, tapped on the calipers with a dead-blow hammer, and did all bleeding with the car running, which seems to have done a decent job. I did a super fast test drive and the ABS warning light turned off after a couple minutes.

The 6 piston calipers and stock A7 akebono pads are definitely better than the stock brakes, even with some air probably still in the system. I'll drive it for a bit, bed the rotors, do some ABS stops if I can, and do some more bleeding again soon.

I'm thinking about doing some gravity bleeding, but not sure if it will work because I had to pump the Motive up to 30 PSI to get any fluid moving out of the rear calipers when I bled with that method early on. Anyone gravity bleed their S4 brakes?

Also, if anybody knows how to activate the ABS pump via VCDS, please let me know

[hardfive]

Thanks, hardfive! Good info. How are you running the ABS test? I'll buy another tool if I need to.

vag com vcds cable. abs > output test

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[Mr. Sneaky]

I just went through this with obd eleven. It wasn’t channel 1 it’s channel 10 to do brake bleed.

[LoloHaole]

I just went through this with obd eleven. It wasn’t channel 1 it’s channel 10 to do brake bleed.

Thank you! I will try that. I'm using VCDS but I think the "group" is the same as channel in obd11.

After bedding the brakes really well the pedal feels better and stopping power is very, very good. I'm optimistic that doing the ABS pump and another couple rounds of bleeding with the car running should do the trick.

[LoloHaole]

I can 100% confirm that the "Group" is 010 for the B8.5 in order to run the ABS pump.

There wasn't a prompt to press the pedal at the start, only to do the bleeding steps / pump pedal 10x while the ABS pump was running (very loudly). It also didn't leave much time to press the "next" button, but after a couple of attempts we got it all bled. I started with the inner bleed screws on the front brakes, then did the process again with the outer ones.

I then did another couple rounds of bleeding with the car running, and now my pedal feels EXCELLENT, and stopping power is massive with 6 pistons up front.

I hope this helps anyone who finds this thread in the future.

[Mr. Sneaky]

Yes... all the cryptic instructions are a little much to take in. Glad you were able to sort it out. *digital High five*

[Allan691]

Yes... all the cryptic instructions are a little much to take in.

Ain’t THAT the truth! This thread was super helpful, but... Still have more questions:

1) Do you crack the bleeder valves while pressing the pedal 10x during the OBDeleven ABS cycling ‘test’..? Or do you wait until you have pressed 10x and then do it while the system seemingly pumps 10x again..? Or do you NOT crack any bleeder valves while the process is taking place and do all the bleeding AFTER the process ends..?
2) If you DO crack the bleeder valves during the cycling ‘test’ process (whether human or system), do you crack one corner and then do another complete test cycle for the next corner..? Or do you try to do all 4 corners during a single cycling process..?

Thanks In Advance.
A


Sent from Italy

2009 Eurospec B8 S4
APR Stage II

[fmzip]

Ain’t THAT the truth! This thread was super helpful, but... Still have more questions:

1) Do you crack the bleeder valves while pressing the pedal 10x during the OBDeleven ABS cycling ‘test’..? Or do you wait until you have pressed 10x and then do it while the system seemingly pumps 10x again..? Or do you NOT crack any bleeder valves while the process is taking place and do all the bleeding AFTER the process ends..?
2) If you DO crack the bleeder valves during the cycling ‘test’ process (whether human or system), do you crack one corner and then do another complete test cycle for the next corner..? Or do you try to do all 4 corners during a single cycling process..?

Thanks In Advance.
A


Sent from Italy

2009 Eurospec B8 S4
APR Stage II

Take a look at this video./ VCDS will prompt you on the screen as to when to what so I'd assume the sequence would be the exact same with OBDEleven:

[Mr. Sneaky]

According to instructions:

Mash pedal hard.

Let it run its pumping.

Open front bleeder screws only before pressing 10x.

Then follow along for the process for rears.

If doing it alone it may time out before you get to rears.

Just redo the process. Skip the fronts and just do rears second time around.

Ain’t THAT the truth! This thread was super helpful, but... Still have more questions:

1) Do you crack the bleeder valves while pressing the pedal 10x during the OBDeleven ABS cycling ‘test’..? Or do you wait until you have pressed 10x and then do it while the system seemingly pumps 10x again..? Or do you NOT crack any bleeder valves while the process is taking place and do all the bleeding AFTER the process ends..?
2) If you DO crack the bleeder valves during the cycling ‘test’ process (whether human or system), do you crack one corner and then do another complete test cycle for the next corner..? Or do you try to do all 4 corners during a single cycling process..?

Thanks In Advance.
A


Sent from Italy

2009 Eurospec B8 S4
APR Stage II

[3.0ss]

After reading through this I have a few questions for those who did the VCDS procedure...
1. How many bleed cycles did you do in VCDS? Are you supposed to complete the cycles till the procedure ends or should you stop once the pedal is firm, how do you know once you're complete?

2. Would it be best to use a pressure bleeder at the same time or is it fine to just fill the reservoir and complete the cycles.

3. So the same procedure applies to the rear calipers? i.e starting the procedure but opening/closing the rear bleeders instead of the fronts?

Thanks

[3.0ss]

Just wanna add on here, I just finished up bleeding with VCDS and the pedal feels AMAZING now! After swapping in SS lines all around and new rear calipers, I used a pressure bleeder at 2bar and bled each caliper 6 times, I thought surely that would be enough. Nope. The pedal felt horrible, the first 7/8ths of pedal travel was a deadzone, there was no bite until the very bottom of the pedal. So I tried out the VCDS procedure. Mine did not work like that video posted above where VCDS walks you through each step. For me, when I pressed on/off/next it would run the ABS pump and would not stop running it unless I closed out of the menu. I made it work but I did my own process instead of it walking me through it. What I did for each caliper was pump the pedal 10 times, open the first bleeder(DF, PF, DR, PR), then let the ABS pump run for 10sec and shut it off, close the bleeder. After individually bleeding the front driver and passenger caliper, I would then open both bleeders and do both at the same time, then move on to the rear and do the exact same process. Did that whole process to the front and rear probably 4-5 times. I did not have the pressure bleeder on the reservoir while doing the ABS procedure. After that, I followed it up with the pressure bleeder and did the regular bleeding process about 5 times. So yeah, that seemed to do the trick. I can't get over how great the pedal feels now.

[Allan691]

Just wanna add on here, I just finished up bleeding with VCDS and the pedal feels AMAZING now! After swapping in SS lines all around and new rear calipers, I used a pressure bleeder at 2bar and bled each caliper 6 times, I thought surely that would be enough. Nope. The pedal felt horrible, the first 7/8ths of pedal travel was a deadzone, there was no bite until the very bottom of the pedal. So I tried out the VCDS procedure. Mine did not work like that video posted above where VCDS walks you through each step. For me, when I pressed on/off/next it would run the ABS pump and would not stop running it unless I closed out of the menu. I made it work but I did my own process instead of it walking me through it. What I did for each caliper was pump the pedal 10 times, open the first bleeder(DF, PF, DR, PR), then let the ABS pump run for 10sec and shut it off, close the bleeder. After individually bleeding the front driver and passenger caliper, I would then open both bleeders and do both at the same time, then move on to the rear and do the exact same process. Did that whole process to the front and rear probably 4-5 times. I did not have the pressure bleeder on the reservoir while doing the ABS procedure. After that, I followed it up with the pressure bleeder and did the regular bleeding process about 5 times. So yeah, that seemed to do the trick. I can't get over how great the pedal feels now.

Daaaemn That’s a lotta work. I think I’ll stick with my shitty feel.


Sent from Italy

2009 Eurospec B8 S4
APR Stage II

[3.0ss]

Daaaemn That’s a lotta work. I think I’ll stick with my shitty feel.


Sent from Italy

2009 Eurospec B8 S4
APR Stage II

haha you certainly don't have to do it as many times as me, I did wayy overkill just to be certain since I didn't want to deal with lifting the car up again. You could probably get all the air out in 1-2 passes doing regular pressure bleeding and cycle the pump before opening each bleeder. It is worth it lol!