I think I've got a problem with my brakes, the dealer doesn't. Help please!

[sc68z28]

Brake blending is perfect once the car has been going for a while. The issue at start up is, you don’t know if your going to get recup (ie blended) braking or just mechanical. Thats where the different/unpredicatable pedal pressure problem arises.

The regen, on my MY23 RWD, is intermittent (on/off) after over night parking for about a mile.
I see it, just like in your video, BUT there is NO "different/unpredictable pedal pressure" .
The blending between Regen and Mechanical braking is perfect, both before and after brake hose recall.
I am sensitive to this, as I service my own brakes after warranty. Retired retail tire/automotive retail store manager w/ASE certifications Brake and suspension.
---Bill.

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[mystermykee]

EDIT: I should add I've got PCCB, in case that makes any difference ?.

Whoa there! No need to rub it in our faces.... ?

 

[mystermykee]

@BigBob

That is not normal. Reminder, Porsche dealer service centers competency levels vary by location.

Also, from your video it sounds like you have PSCBs? Yours are pretty noisy. Mine sounded like that before I got updated pads under warranty.

 

[BigBob]

@BigBob

That is not normal. Reminder, Porsche dealer service centers competency levels vary by location.

Also, from your video it sounds like you have PSCBs? Yours are pretty noisy. Mine sounded like that before I got updated pads under warranty.

Nope. Just regular brakes. 20% worn at front 40% worn at back apparently.

Only notice the noise of them when this thing is happening in mornings.

Seems I’m not the only one and maybe the car they said they’d compared it to was also doing it. That said, I still don’t think it’s correct.

 

[mystermykee]

My brakes got messed up in a different way recently. There is a hissing friction sound at low speeds (around 5mph) and towards the very end of braking (when getting close to 0mph)

First check by dealership said nothing wrong. But there is no way the noise is normal. Will be scheduling another appointment.

Anyone gets that issue?

Seems like it's happening when the mechanical brakes are engaged. You can try and see if the noise happens regardless of speed by temporarily putting the car in Neutral, then pressing on the brakes.. Just don't have your foot on the brake pedal when putting the car back into Drive (while moving obviously)

 

[mystermykee]

Nope. Just regular brakes. 20% worn at front 40% worn at back apparently.

Only notice the noise of them when this thing is happening in mornings.

Seems I’m not the only one and maybe the car they said they’d compared it to was also doing it. That said, I still don’t think it’s correct.

Hrm interesting. I've driven a loaner with standard rotors and it was not that noisy.

 

[figure1a]

My brakes got messed up in a different way recently. There is a hissing friction sound at low speeds (around 5mph) and towards the very end of braking (when getting close to 0mph)

First check by dealership said nothing wrong. But there is no way the noise is normal. Will be scheduling another appointment.

Anyone gets that issue?

Regen doesn't brake all the way to zero. What you are hearing are the brake pads on the front rotors.

 

[thefunkygibbon]

I don't know. honestly. could someone describe what it should look/behave/feel/see like if it's working and not working?
I have my regen set all the time to auto and always just let that brake for me unless I need to come to a stop/traffic not around . I don't think I've felt the brakes behave differently after starting a journey.
is there some kind of error/dashboard light which shows it's not working ?

 

[BigBob]

I don't know. honestly. could someone describe what it should look/behave/feel/see like if it's working and not working?
I have my regen set all the time to auto and always just let that brake for me unless I need to come to a stop/traffic not around . I don't think I've felt the brakes behave differently after starting a journey.
is there some kind of error/dashboard light which shows it's not working ?

This is recuperation braking we’re talking about. In when you apply the brake pedal rather than the lift-off accelerator braking from the auto regen button.

Pretty sure you can’t fiddle with the recuperation braking settings.

 

[gtm]

@BigBob -
Took a second look at your video. Regen braking is there when you are "braking" at lower speeds. Regen stops when you brake from higher speeds (25 - 27 mph, hard to tell the exact speed). Perhaps the software was changed so that the mechanical brakes are only engaged to clean the rotors when you exceed a certain speed and it's fast enough to work the brakes sufficiently. Stopping from 10 mph probably puts very little pressure on the rear brake pads in particular.

Does the regen go back to "full time" after a couple of higher speed stops? If not then your car has issues. If it does I'm guessing it's a software change for implementing the brake cleaning process.

That said, you should not feel a difference in the pedal between the mechanical brakes and regen.

 

[BigBob]

@BigBob -
Took a second look at your video. Regen braking is there when you are "braking" at lower speeds. Regen stops when you brake from higher speeds (25 - 27 mph, hard to tell the exact speed). Perhaps the software was changed so that the mechanical brakes are only engaged to clean the rotors when you exceed a certain speed and it's fast enough to work the brakes sufficiently. Stopping from 10 mph probably puts very little pressure on the rear brake pads in particular.

Does the regen go back to "full time" after a couple of higher speed stops? If not then your car has issues. If it does I'm guessing it's a software change for implementing the brake cleaning process.

That said, you should not feel a difference in the pedal between the mechanical brakes and regen.

Hi. It isn’t acting consistently at all and not really speed dependent as to which braking method it decides to use. I guess the video may not highlight that, but it’s the case generally that it’s totally random for the first few miles as to what you get.

I’m at a bit of a loss as to what to do about it. Dealer is disinterested in investigating it, saying things like the car manual is probably wrong. I’d have hoped at least that they’d try reinstalling the relevant software, but pretty sure they haven’t.

I guess maybe they’re right and Porsche have changed the brake cleaning process but haven’t told anyone yet or updated their manual. Not sure why they’d choose to change it either, unpredictable brakes don’t strike me as a step forward. But I guess Porsche’s software engineers are pretty on the ball……

 

[mystermykee]

Hi. It isn’t acting consistently at all and not really speed dependent as to which braking method it decides to use. I guess the video may not highlight that, but it’s the case generally that it’s totally random for the first few miles as to what you get.

I’m at a bit of a loss as to what to do about it. Dealer is disinterested in investigating it, saying things like the car manual is probably wrong. I’d have hoped at least that they’d try reinstalling the relevant software, but pretty sure they haven’t.

I guess maybe they’re right and Porsche have changed the brake cleaning process but haven’t told anyone yet or updated their manual. Not sure why they’d choose to change it either, unpredictable brakes don’t strike me as a step forward. But I guess Porsche’s software engineers are pretty on the ball……

Have you had this TSB completed? https://static.nhtsa.gov/odi/tsbs/2025/MC-11016718-0001.pdf

If not, have your dealer do it. It also updates the PSM. Could be a long shot, but that might fix the inconsistent behavior of the mechanical brakes. Doesn't hurt I guess... At least you'll have great brake pedal feel!

 

[gtm]

@BigBob - So I drove my car today (J1.1). My regen/mechanical cleaning routine has changed it seems. I noticed a pattern. "Braking" under 25 +/- mph is done by regen when starting out. Braking above 25 mph show no regen on the dash. If I exceeded 25 mph and coasted down to 20 the braking was still mechanical only. Exceeding 25 mph seems to trigger mechanical braking regardless of how fast you are going when you actually depress the pedal. My pedal feel is identical either way so this pattern could have existed for quite some time without my noticing. Three stops with no regen and the system went back to "normal" operation (regen braking until slowed to 3 mph).

No idea if this is your pattern or not but your inconsistent pedal feel is not normal. If I wasn't looking at the power meter I would never have known if the braking was regen or mechanical.

 

[BigBob]

@BigBob - So I drove my car today (J1.1). My regen/mechanical cleaning routine has changed it seems. I noticed a pattern. "Braking" under 25 +/- mph is done by regen when starting out. Braking above 25 mph show no regen on the dash. If I exceeded 25 mph and coasted down to 20 the braking was still mechanical only. Exceeding 25 mph seems to trigger mechanical braking regardless of how fast you are going when you actually depress the pedal. My pedal feel is identical either way so this pattern could have existed for quite some time without my noticing. Three stops with no regen and the system went back to "normal" operation (regen braking until slowed to 3 mph).

No idea if this is your pattern or not but your inconsistent pedal feel is not normal. If I wasn't looking at the power meter I would never have known if the braking was regen or mechanical.

Thanks.
I’ll have a closer look at speeds

 

[Boss Hogg]

One other point to throw in the mix, regen braking switches off when the battery is at high SoC, like 100%, so it only uses mechanical brakes in this condition. It is hard to see your SoC and your problem is inconsistency, but perhaps the braking system is getting signals from the battery that it's full?

Re Porsche, I'd call or write Porsche UK to highlight your concerns about the change in the braking behaviour as a long term owner and importantly that after investigation the dealer could not give a satisfactory reasons for the change stating that the manual with respect to the braking system is 'probably wrong' (the most important safety system!!) . You now have low confidence and want it checked/diagnosed/explained thoroughly, they may send your video to Germany for a proper review. There have been high profile issues with braking and the Taycan, global brake hose recall a prime example, so I'd be surprised if they don't take you seriously.

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