Electronic Parking Brake (EPB) failure at 4 years 1 month causes expensive repairs

[MY22PCT]

Hi,

I have an 'in-flight' issue with a Porsche Centre and Porsche GB and would appreciate trading notes with anyone who has had similar.

In short: the EPB on my Turbo S Cross Turismo has run out of possible adjustment due to 'wear & tear'. This apparently requires replacement of the EPB components, both rear PCCB discs and the pads. A bill of approximately £10K. As usual with these sort of things I've learned a lot in a short space of time!

Thanks for any thoughts and insights from folks who have, or are, on the same journey.

Kind regards

Matt

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[AutoX]

I don't understand how the PCCB disc and pad can get worn down to the point that they need replacing.

 

[MY22PCT]

So that’s how I started.

However, in a drum-in-disc electronic parking brake system like the Taycan’s, the parking brake operates using internal brake shoes that press against a cylindrical drum surface formed within the “hat” of the rear brake disc, separate from the outer disc surface used by the pads.

As these shoes wear down, the actuator must travel further to achieve contact, eventually exceeding its adjustment range, at which point the system can no longer generate sufficient holding force.

Because the drum surface is machined as an integral part of the brake disc and is not a separately replaceable component, any wear, scoring, or loss of effective geometry within that internal drum—together with worn shoes—means the only way to restore correct parking brake function is to replace the entire disc assembly, even if the outer braking surface and pads remain within specification

So, it’s not wear of the brake discs that causes the need for replacement in this case. Bad luck, if like me, you have PCCB brakes.

 

[Midlifecrisis]

That is ridiculous! This sort of thing will kill Porsche as most normal people will not buy a car that has the potential for the sort of bills we are seeing when they realise what they are letting themselves in for. Do you have an extended warranty? Or is that irrelevant because the part has worn out?

 

[Murph7355]

I'm sure there's a thread on here where shoes have disintegrated and I think dealers picked up the tab.

If the car's been serviced by them from new, I would be going down the "so this can go from fine to causing £10k damage between services?" avenue. When the cheeky feckers tell me my tyres need replacing when. They have 6mm if tread left I find it amusing they leave this stuff.

Aren't these discs made of components? So could the bit with the drum not be replaced without the (expensive) composite disc part having to be?

(Not helpful... But there is way less than zero reason to have PCCB discs on a Taycan. Or, frankly, most any car that isn't used solely for heavy track work).

 

[Murph7355]

That is ridiculous! This sort of thing will kill Porsche as most normal people will not buy a car that has the potential for the sort of bills we are seeing when they realise what they are letting themselves in for. Do you have an extended warranty? Or is that irrelevant because the part has worn out?

Warranty won't cover brakes.

And most normal people aren't spending £160k+ on a car

Sadly, time and again we see the contempt with which they treat customers.

 

[MY22PCT]

Warranty won't cover brakes.

And most normal people aren't spending £160k+ on a car

Sadly, time and again we see the contempt with which they treat customers.

Warranty won't cover brakes.

And most normal people aren't spending £160k+ on a car

Sadly, time and again we see the contempt with which they treat customers.

Hi Murph

I’m looking into this very carefully.

Interestingly the Porsche Warranty covers every component in the car against manufacturing defect.

In the UK pre-Sept 2025 extended warranty, there is a defined ‘exhaustive wear and tear list’ for exclusions due to wear and tear.

This list has only two brake components: “discs and pads”.

In my car’s case it is problems with the actuators, brake shoes and the inside drum surface.

Does this make sense, and what do you think?

ind regards

matt

 

[MY22PCT]

I'm sure there's a thread on here where shoes have disintegrated and I think dealers picked up the tab.

If the car's been serviced by them from new, I would be going down the "so this can go from fine to causing £10k damage between services?" avenue. When the cheeky feckers tell me my tyres need replacing when. They have 6mm if tread left I find it amusing they leave this stuff.

Aren't these discs made of components? So could the bit with the drum not be replaced without the (expensive) composite disc part having to be?

(Not helpful... But there is way less than zero reason to have PCCB discs on a Taycan. Or, frankly, most any car that isn't used solely for heavy track work).

I'm sure there's a thread on here where shoes have disintegrated and I think dealers picked up the tab.

If the car's been serviced by them from new, I would be going down the "so this can go from fine to causing £10k damage between services?" avenue. When the cheeky feckers tell me my tyres need replacing when. They have 6mm if tread left I find it amusing they leave this stuff.

Aren't these discs made of components? So could the bit with the drum not be replaced without the (expensive) composite disc part having to be?

(Not helpful... But there is way less than zero reason to have PCCB discs on a Taycan. Or, frankly, most any car that isn't used solely for heavy track work).

There is a very familiar thread and there is a Workshop Campaign WNK6 that refers to ‘below specification actuators’. This has caused replacement of specified actuators on the rear OS, rear NS or both. My VIN is not in scope although all the model, variant & PCCB permutations appear to be the same.

There are YouTube videos of failed actuators causing drag of the shoes on the inside of the drum and causing damage.

I agree with your comment about full servicing and care by Porsche should prevent this sort of occurrence. My car has had at least 7 VHCs and none have identified any problems other than when the car went in for an EPB fault and two ‘loss of position’ faults.

Unfortunately, the rear PCCB discs were not designed in a componentised fashion so one bit fails and you’re stuffed.

Kind regards

Matt

 

[BjörnfromHamburg]

(Not helpful... But there is way less than zero reason to have PCCB discs on a Taycan. Or, frankly, most any car that isn't used solely for heavy track work).

PCCB is not build for heavy track use, they will "wear down" fastly.
And if used on track, only with different brake-pads.

 

[Boss Hogg]

This is interesting, I have a parking brake problem on my J1.2. It very noticeably rolls back on one side when parking on a hill, feels like it's defective but Porsche have tested and confirmed as normal behaviour. As a previous J1.1 owner it feels very wrong (my J1.1 parking brake was rock solid over 60k miles) but I'm being told J1.2 cars only have a parking brake actuator on one side of the car due to cost saving unlike J1.1 that has actuators on both sides. At least my J1.2 would be half the repair bill if the actuator + disc fails -however the single actuator and disc will be under double the weight/stress!

 

[Gino]

PCCB is not build for heavy track use, they will "wear down" fastly.
And if used on track, only with different brake-pads.

How many miles are the brakes supposed to last on the Taycan? Front? Rear/Parking brake actuators on J1.1?
If you drive mostly stop & go around town would that wear the parking brake pads/actuators faster? If so how many miles before you need to replace them? If the parking brake actuators/pads can not sufficiently hold the vehicle then will it just roll down an incline when parked or is there some mechanical linkage which prevents the wheels from turning when the vehicle is parked & turned off?

 

[BjörnfromHamburg]

I never heard of usual wear on the P-brake and would assume it lasts as long as the PCCB.
If you park a lot on steep terrain, that would possibly wear the material faster. If J1.2 only has one side P-brake, that could cause faster wear, too.
It is theoretically possible on private ground to leave the car in N with no P-brake engaged.
I fear though, the Taycan won't shut down and lock the doors, than.
It's a delicate topic for PCCB owners.
And a possible expensive one.

 

[Gino]

I never heard of usual wear on the P-brake and would assume it lasts as long as the PCCB.
If you park a lot on steep terrain, that would possibly wear the material faster. If J1.2 only has one side P-brake, that could cause faster wear, too.
It is theoretically possible on private ground to leave the car in N with no P-brake engaged.
I fear though, the Taycan won't shut down and lock the doors, than.
It's a delicate topic for PCCB owners.
And a possible expensive one.

I’d be upset if my parking brake components need to be replaced before my front & rear brakes have been replaced at least 2 times.
I replace my rotors/pads every 80K miles on my Mercedes Sprinter 2500 but I usually downshift on hills rather than ride the brakes.
I assumed the electric motors use regenerative braking on hills so I would expect brakes on my 2021 Taycan RWD to last at least 60K miles. Am I way off or should I prepare for replacing brakes more often?

 

[BjörnfromHamburg]

No, even steel-brakes should go for 100 kmiles and more easily, if not used on racetrack.

 

[Gino]

No, even steel-brakes should go for 100 kmiles and more easily, if not used on racetrack.

Thanks, that’s what I was hoping. The brakes on my Sprinter in the front would last 80K but the rears was 120K. I was told the front brakes do all the work on such a heavy vehicle so they get replaced more often.
I’ll never get to 100K miles on my Taycan even after another 10-15 years since I only drive it 4K miles a year on average. Hopefully I won’t have to worry about brakes for a very long time.

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