Replacing Rear Pads with Electric Parking Brake (EPB)

[Lozzy15]

Lozzy15 submitted a new resource:

Replacing Rear Pads with Electric Parking Brake (EPB) - A guide to replacing rear pads when the car has a electric parking brake.

Welcome to my guide for replacing the rear pads on a 2017 Leon with an electric parking brake. The job itself it rather simple and straight forward, that being said you must be competent with working on the brake system of your car before you attempt this.

DO NOT PROCEED IF YOU ARE NOT COMPETENT, FAILURE OF THE BRAKING SYSTEM CAN POTENTIALLY KILL.

The following tools and software will be needed to perform this job.

Tools:
7mm...

Read more about this resource...

 

[Lozzy15]

If anyone who uses this guide and does not use VCDS, please comment about your experience so I can amend the guide. Pictures/Screenshots would be most appreciated, and your contribution will be credited in the guide.

Many thanks,
Lozzy

 

[csd_19]

Good guide, thanks for that.

Only thing I'd suggest is not using copper grease but Ceratec brake grease instead, easily obtained from EuroCarParts etc

 

[RUM4MO]

I've only ever done this on a 2011 Audi S4, and I'm sure that VCDS had a dedicated "task" for doing this and so did not create any fault codes. I'd also add, if possible use a battery maintenance unit and not a battery charger as most people should have a smart charger and they tend to charge through/along a predetermined voltage profile, whereas a maintenance unit will always apply a constant 12.?V, so if the battery is still fit/healthy, just leave the "supporting" part out I think. I'm guessing that some levels of Leon with electric handbrakes do not need the pistons rotated while being pressed back, and some do, no doubt I'll find out when/if I need to replace the rear pads on my daughter's 2019 Leon Cupra, also so far on my Audi S4, I've only ever just retracted the pistons using the motors as it is still on its original pads, if/when I need to replace the rear pads, I'll probably need to rotate the rear pistons to get them back to their initial position before fitting the new pads etc.

Edit:- oh and silicon grease on the calliper guide pins as they "live" inside rubber dampers and using some greases will end up swelling these rubber elements.

Another Edit:- sticking wheels, plan to never have this happening, service your brakes every year and first time scrub up the hub faces and apply either Ceratec brake grease or aluminium loaded grease to the centre bore - I used Ceratec brake grease initially on my S4 hubs, but really aluminium loaded grease will end up being cheaper.

 

[Lozzy15]

I've only ever done this on a 2011 Audi S4, and I'm sure that VCDS had a dedicated "task" for doing this and so did not create any fault codes.

I'm using an older version of VCDS which may be the issue.

I'm guessing that some levels of Leon with electric handbrakes do not need the pistons rotated while being pressed back, and some do

These ones didn't need to be rotated while being pressed back in, even though they had the marks for the tool as seen in this picture:

 

[RUM4MO]

Yes, a bit misleading when the ends of the pistons have these 2 rebates to engage a piston retraction tool! I have used a piston retraction tool on lots of my VW Group cars - always with the adaptor side that grips these 2 points, but when I bought my 2011 Audi S4 slightly used, I bought a specific adaptor for later VW Group cars that had another sort of "gripping" arrangement, but after retracting the brakes a couple or so times to clean them up, I got round to considering that no further action was required when fitting new discs and/or pads - but then read that the pistons needed to be properly "zero'd" when fitting new pads - time will tell if on that version of "rear brake calliper with electric handbrake facility" that the 2011 Audi S4 has, needs just pressing in after retracting, or pressing and rotating after retracting. I felt the need to comment on this seeing as it was created as a resource and one that Cupra folk might use, and so adding in a bit of caution wrt to how to achieve the final "zero'ng" of the rear pistons. I'm sure that most people could look up the workshop manual that is on this forum for confirmation wrt the Cupra - I should have before writing this!!

 

[Lozzy15]

Yes, a bit misleading when the ends of the pistons have these 2 rebates to engage a piston retraction tool! I have used a piston retraction tool on lots of my VW Group cars - always with the adaptor side that grips these 2 points, but when I bought my 2011 Audi S4 slightly used, I bought a specific adaptor for later VW Group cars that had another sort of "gripping" arrangement, but after retracting the brakes a couple or so times to clean them up, I got round to considering that no further action was required when fitting new discs and/or pads - but then read that the pistons needed to be properly "zero'd" when fitting new pads - time will tell if on that version of "rear brake calliper with electric handbrake facility" that the 2011 Audi S4 has, needs just pressing in after retracting, or pressing and rotating after retracting. I felt the need to comment on this seeing as it was created as a resource and one that Cupra folk might use, and so adding in a bit of caution wrt to how to achieve the final "zero'ng" of the rear pistons. I'm sure that most people could look up the workshop manual that is on this forum for confirmation wrt the Cupra - I should have before writing this!!

I've just double checked on this as you had me thinking about it again. According to the repair docs, it's the same for multi link/live axle variants. So in either case, the piston just pushes back in without the need for the piston to be rotated at the same time:

 

[RUM4MO]

Thanks for clarifying that wrt the Cupra - in the past I have used my piston rewind tool, with a bit of wood between the rotating end and the piston end to retract normal front calliper pistons without forcing the piston to rotate, but I also now have a second simple pad "expander" which might be strong enough to move the Cupra rear piston in after the handbrake motor has been retracted electrically.

 

[SuperV8]

I've only ever done this on a 2011 Audi S4, and I'm sure that VCDS had a dedicated "task" for doing this and so did not create any fault codes. I'd also add, if possible use a battery maintenance unit and not a battery charger as most people should have a smart charger and they tend to charge through/along a predetermined voltage profile, whereas a maintenance unit will always apply a constant 12.?V, so if the battery is still fit/healthy, just leave the "supporting" part out I think. I'm guessing that some levels of Leon with electric handbrakes do not need the pistons rotated while being pressed back, and some do, no doubt I'll find out when/if I need to replace the rear pads on my daughter's 2019 Leon Cupra, also so far on my Audi S4, I've only ever just retracted the pistons using the motors as it is still on its original pads, if/when I need to replace the rear pads, I'll probably need to rotate the rear pistons to get them back to their initial position before fitting the new pads etc.

Edit:- oh and silicon grease on the calliper guide pins as they "live" inside rubber dampers and using some greases will end up swelling these rubber elements.

Another Edit:- sticking wheels, plan to never have this happening, service your brakes every year and first time scrub up the hub faces and apply either Ceratec brake grease or aluminium loaded grease to the centre bore - I used Ceratec brake grease initially on my S4 hubs, but really aluminium loaded grease will end up being cheaper.

No need to rotate the rear piston on either A4/S4 EPB or any Leon with EPB.
The act of plugging in the diagnostic VCI and 'activating the EPB function' and selecting 'open caliper' electrically winds back the internal screw within the rear caliper - leaving the piston free to be pushed back like any front caliper piston. (apart from some Citroen's how had the handbrake on the front caliper )

Easiest method to push pack the piston is using a large straight screwdriver in the slot in the top of the caliper to lever the old pad against the piston.

Just to note - you can manually wind back the piston screw on the back of the VAG(TRW) EPB in an 'emergency procedure' by disconnecting the EPB connector and using an allen key - but you still need a diagnostic VCI to perform the brake re-set function so this is only useful in an emergancy!

 

[SuperV8]

Thanks for clarifying that wrt the Cupra - in the past I have used my piston rewind tool, with a bit of wood between the rotating end and the piston end to retract normal front calliper pistons without forcing the piston to rotate, but I also now have a second simple pad "expander" which might be strong enough to move the Cupra rear piston in after the handbrake motor has been retracted electrically.

Pushing back any caliper piston shouldn't need much force. You are only pushing the piston back past its seal and pushing the fluid back up the line.
If you need need to strongly push the piston back with quite some effort - I would be suspecting you need a caliper re-build or new caliper.

Note: its good practice to crack the bleed nipple from the caliper and catch the excess fluid when you push a piston back so you're not pushing dirty fluid back up into the brake system.

 

[SuperV8]

If anyone who uses this guide and does not use VCDS, please comment about your experience so I can amend the guide. Pictures/Screenshots would be most appreciated, and your contribution will be credited in the guide.

Many thanks,
Lozzy

Nice write up.
You can manually open up the EPB on most cars in an 'emergency procedure' with an allen key (image shared above) but I believe you can only properly re-set the caliper with a VCI tool (vehicle car interface) You can just fit new pads/disc and activate the park brake a few times but i'm sure there will be some counter/wear measurement you will be re-setting with the VCI so the car knows it has new pads, so personally I wouldn't do an EPB brake job without a VCI - but you can in an emergency.

I agree there is debate on best practice on whether or not to grease the pad abutment/contact areas.
BMW do not recommend this, but other OEM's do.
Your outcomes depends on either corrosion binding your pads, or brake grease over time can attract detritus and dry up also causing the pads to bind. Pick one!
If you regularly - as you should (less than 2 years) inspect/clean and maintain your brakes adding brake grease won't be an issue - I personally do add a thin smear of brake grease (not copper anti seize) but you should not add grease to the back of your pads if you have rubber steel composite shims (most premium pads do)
This practice is left over from the days when pads were without anti-noise shims - just a metal back plate, and the grease anti-noise property was only ever temporary.
Modern pads have multi layer rubber and steel composite anti-noise shims, grease will be of no benefit and may even degrade the rubber layer quicker reducing its anti-noise benefit.
The ONLY time you would use brake grease on the back of the brake pads is if they are using clip on stainless steel anti-noise shims like many Japanese/Asian manufactures do - then you should add a thin smear underneath this stainless steel clip on shim.
OR if you are using budget pads which do not have rubber steel composite anti-noise shims.

One point regarding the wheel bolts - these should always be torqued up in a star/criss-cross pattern.

One point regarding changing the disc - I know you didn't change the disc - if if you do then cleaning the hub face is probably the most important step and often missed on you tube 'how to' videos. The disc mounting surface needs to be spotless - discs are machined to less than 50micros runout and less than 15microns thickness variation (0.015mm!) That is very high precision - and for a reason - then to mount this on a none flat/rusty hub will cause this disc to 'run out' of true meaning that at each point the disc runout is highest at opposite sides it will contact the pad and wear the disc thin at this single point. Over several hundred to several thousand miles this thick and thin wear on the disc will be noticeable by the driver and is called brake judder. Only fix is another new set of discs!

 

[RUM4MO]

Logged faults after running the "linings change" operation, as well as the same fault logged in the ABS controller - I found another in the Instruments controller, both with the same day/date/time stamps on them - I'm just mentioning this in case someone first tries just clearing the fault from the ABS controller and does not appreciate that there could be more generated faults logged during this work.

I'm sure a bit more effort or thought could have been given to service access to the guide pins on the rear ATE callipers on the Leon Cupra, I gave up on trying to use more hex bit/socket and used a long arm Allen key, okay a short hex key without its 3/8" adaptor and a suitable ratchet spanner worked well once they were initially slackened off and up to until they needed the final tightening. I have never really liked flexing brake pipes especially very close to the junction of the flexi to its steel stub end.

I used a spot of ceramic brake grease on the contact points in the rear ATE brakes, but just cleaned up the front TRW callipers, time will/might tell if the TRW front callipers/pads will/would have benefitted from a spot of brake grease at the contact points on the pads.
One thing other to pass comment on, the front TRW brakes were fitted initially with Jurid pads, I think that Jurid is now under the same marketing group as Mando, ie Federal Mogul - though if I remember correctly, the front ATE brakes on my wife's 2015 VW Polo 1.2TSI 110PS are also fitted with Jurid pads from new.

 

[Hairy]

Thanks for this guide, gave me the confidence to do this on my 2018 Ateca rather then pay the dealer £160. I've always changed my own pads but this is my first car with an electric parking brake so thought DIY wasn't an option. I used Carista which was very simple to use.