A6 Rear pad change and all-round brake bleed.

The Black Panther

Adventurer !
So its coming near the time when I'm gonna self fit the RS6 callipers.
All the parts will arrive next week. Repainted callipers, new backplates, pins, pads, pipes etc

Fronts

Fitting the front, discs, pads and calliper should be no real problem. Ive done these things before. I can't see anything special about it.
  • Am i missing something and being too presumptuous ?

Rears However !

Electronic parking brake on the rear posses questions i do need answers for.
The original complete calliper and Electronic parking brake is coming off. The RS6 calliper shave the electronic parking brake with them so i will be using them.

  • The Electronic parking brake. What the deal when swapping over complete callipers ?
  • Is a special tool required to wind back pistons on rears ?
  • Brake bleeding is its as simple as traditional bleeding or do i have to with the ignition non and allow the ABS pump to assist or push out ?
Finally

  • Copper slip whats used now ?
 
Last edited:

RAF_S7

Well-Known Member
Gold Supporter
Winding back the rear electronic brake is usually done vie the OBD2 port, using VCDS or another suitable solution.

You cannot wind them back mechanically.


 

oldoiler

Registered User
You'll have find someone who has a vc unit to talk to the brake system ecu this will correct any data mis match setting etc


Sent from my iPhone using Tapatalk Pro
 

The Black Panther

Adventurer !
So if I mechanically remove the electronic handbrake and reassemble I can post re calibrate the unit with caliper using the VC unit.
In essence what I'm asking is the previous relative position of the removed electronic parking brake to the piston is not mechincally relative to each other on rebuild and can be recalibrated electronically ?
You'll have find someone who has a vc unit to talk to the brake system ecu this will correct any data mis match setting etc


Sent from my iPhone using Tapatalk Pro
So
 

Rhyso

Registered User
You need to use VCDS or equivalent diagnostic tool to wind the piston back. If you try to move it back yourself you will destroy the motor!!

You then use VCDS to recalibrate once the once disks and pads are fitted. You will hear the piston wind in and out as it recalibrates. So to answer your question; yes everything is recalibrated electroncially

The process itself is very straightforward. The hardest part was loosening off the bolts holding the caliper and getting the disk off the hub as they were practically welded on!!
 

The Black Panther

Adventurer !
Numerous videos i have watched show removal of the ELEC park brake motor itself, manual winding of the piston back without mechanical detriment. Then re attachment of the ELEC park brake motor without any damage.

Are the two components interfaced in such a way that the new postion of the piston in relation to ELEC park brake motor is not critical during the commissioning and calibration phase and the ELEC park brake motor can zero itself against on ( handbrake on) and off (Parking brake released completely to zero point) relative to the pistons position ?

Short hand does both the piston have to be fully wound back to zero and the ELEC park brake motor also taken to zero point and both then calibrated together at zero point together to satisfy calibration criteria?

My guess is the relative physical position of the piston to the ELEC park brake motor is variable and not absolute and that the ELEC park brake motor will calibrate itself with the piston on numerous variable positions after for example a brake pad change as the position of piston in relation to the ELEC park brake motor will change based on pad wear, brake disc width again based on wear and other possible factors.

I commission Nuclear and Gas turbines large big big massive ones that are hugely complex, and we do a lot of trouble shooting as part of our process - hence the long worded question. Your previous post doesn't answer this question because i guess because you don't know the answer as you carried out the operation the traditional way with the correct tools. :)

Where as.

I don't have a VCDS and kinda don't want to spend the money to buy one. So im opting for the the heath robinson method - i think tbc. :)

You need to use VCDS or equivalent diagnostic tool to wind the piston back. If you try to move it back yourself you will destroy the motor!!

You then use VCDS to recalibrate once the once disks and pads are fitted. You will hear the piston wind in and out as it recalibrates. So to answer your question; yes everything is recalibrated electroncially

The process itself is very straightforward. The hardest part was loosening off the bolts holding the caliper and getting the disk off the hub as they were practically welded on!!
 
Last edited:

Rhyso

Registered User
You've spent all this money on your motor, yet quibble about spending £250 on a diagnostic tool which can save you money over the long term ownership of your car :tearsofjoy:
 

The Black Panther

Adventurer !
I know. But I'm Scottish. Hate parting with money unless absolutely necessary. Its just a thing i have. Plus i like the DIY ethos. :)

You've spent all this money on your motor, yet quibble about spending £250 on a diagnostic tool which can save you money over the long term ownership of your car :tearsofjoy:
 

The Black Panther

Adventurer !
Do you have VCDS ? Lend me it. Please :)
You need to use VCDS or equivalent diagnostic tool to wind the piston back. If you try to move it back yourself you will destroy the motor!!

You then use VCDS to recalibrate once the once disks and pads are fitted. You will hear the piston wind in and out as it recalibrates. So to answer your question; yes everything is recalibrated electroncially

The process itself is very straightforward. The hardest part was loosening off the bolts holding the caliper and getting the disk off the hub as they were practically welded on!!
 

RAF_S7

Well-Known Member
Gold Supporter
If you post in the VCDS Map Forum (Tab at the top of the page) you may find someone with VCDS close to you who can help :racer:
 

The Black Panther

Adventurer !
Thanks RAF S7. I'm so short of time right now with things I'm considering / conceding to getting the RS6 Breaks and the coiler overs fitted at a local tuning shop. Ive only been home 3 days in the last 8 weeks and then I'm home for 10 days and away for 5 more straight away.
If you post in the VCDS Map Forum (Tab at the top of the page) you may find someone with VCDS close to you who can help :racer:
 
Top