As far as I can see, if I understand it correctly, you need special equipment to replace the rear pads on many Audi's. Otherwise you won't be able to retract the rear calipers. Is this also true for the 2003 A8 3.7 V8?
3
-
I use a scantool when doing brake work on that style caliper. Sometimes theres a non scantool procedure you can do. But i have seen guys jump power and ground to retract the screw and then you can press in the piston. I’ve had to do it when bailing someone out. They somehow messed up the service procedure and the screw wasn’t fully retracted.– BenSep 14, 2018 at 14:16
-
@Ben I figured it would be physically possible to retract the caliper, but knowing VAG, you'd get punished for doing that... Since it's not my own car, i'd rather not take that risk. Nice to know that it's at least possible in an emergency.– BartSep 14, 2018 at 17:32
-
Are you sure your car has a electronic caliper parking brake? Looking at SI it looks like you just push the piston in normally.– BenSep 15, 2018 at 16:02
Add a comment
|
2 Answers
You can perform this action with a number of 3rd party diagnostic tools such as VCDS, Carista and OBDeleven.
My uncle had some success removing the electrical mechanism from the rear of the caliper too but I'd suggest against this option given the choice between taking things to bits and buying a diagnostic tool.
answered Sep 14, 2018 at 13:29
-
Excellent answer. I don't have those tools and won't be servicing vehicles that need those anywhere near often, so I can tell the guy he needs to seek someone else for replacing his pads.. I'd think that even VAG vehicles did still allow you to replace something simple as the brakes, but it seems even that is reserved for the dealer, shame on VAG.– BartSep 14, 2018 at 13:40
-
By the way, are the front pads replaceable or do they also require special tools?– BartSep 14, 2018 at 13:42
-
2No specialist tools are required for the front pads. I bought my Carista from Amazon when it was on offer for £9.99 (I know this isn't a shopping advice site) and have found it useful for a number of friends with EML lights coming on. Sep 14, 2018 at 13:44
-
Alright, thanks. Most if not all of the cars I maintain don't have CEL's, a CAN bus, or even electronics. But this guy with his A8 found his running costs way too high, so he asked if I could do a service on his car, and replace the pads. For the latter, he needs to go to the dealer i'm afraid. I've looked at the carista tool, but it seems you also need the advanced module in the app for a higher price. Also, i've never worked with those things so i'm not eager to try if i'm working on the car of someone i don't know really well. But thanks for the info.– BartSep 14, 2018 at 13:57
-
You do get 1 month free trial of the advanced modules on Carista with any new purchase of a genuine dongle but it may be of limited use by the sound of it. Sep 14, 2018 at 14:01
This depends on an electronic parking brake or a mechanical brake. The option varies between Audi models.
Mechanical brakes (lever with a cable) require a simple tool to dial in the piston while applying pressure (or not - one of mine screwed in on it's own, the other required pressure). The tool can be obtained from most local parts houses.
As you realize, for the electronic parking brake you will need a software solution. RossTech's VCDS is one option for a DIY. Some pros use it as well (DiagnoseDan on YouTube is an example). However, unless you are working on VAG vehicles less than a few times, it's not cost effective.
Instructions below are from RossTech's website.
Basic Setting Caution! Do not perform any of these Basic Settings while the brakes are disassembled! Opening, closing, function tests, and otherwise cycling the Electronic Parking brakes should only be done with the pads and calipers properly installed on the rotors. Please follow the procedures EXACTLY. There's a reason for every step. If you skip any prerequisites or other steps here, you are likely to experience "issues" for which no documented resolutions exist, in which case we will not be able to help you resolve them. It is strongly recommended to run a full Auto-Scan first thing to check for any preexisting faults! There have been several reports of repair shops damaging the Electronic Parking Brake System when trying to do rear brakes, but not telling the customer and then sending the car out the door. Open Rear Parking Brake for Pad Change Prerequisites: Connect a battery charger as per repair manual, click photo to enlarge. A8 charger hookup.jpg
See Special Notes
Cycle the Parking Brake ON, then OFF first. [Select] [53 - Parking Brake] [Basic Settings - 04] Group 005 [Go!] Activate the Basic Setting. [ON/OFF/Next] The brake pads are now opening. [Done, Go Back] [Close Controller, Go Back - 06]
Turn ignition off.
The caliper pistons do not move back into the caliper, this is normal.
Note: Check/Change Adaptation Channel 006 (Pad Thickness) after changing the pads.
Open Rear Parking Brake for Repairs 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!] Activate the Basic Setting. [ON/OFF/Next] The brake pads are now opening. [Done, Go Back] [Close Controller, Go Back - 06]
The scan tool can now be disconnected and ignition shut off while mechanical repairs are performed
Close Rear Parking Brake Prerequisites: Connect a battery charger as per repair manual. [Select] [53 - Parking Brake] [Basic Settings - 04] Group 006 [Go!] Activate the Basic Setting. [ON/OFF/Next] The brake pads are now closing. [Done, Go Back] [Close Controller, Go Back - 06]
