periodic "spongy" brakes. that don't stop. if i die please have my family sue Porsche

[Lars]

From a previous post of mine;

Thanks for the replies, I have noticed this a few times at different speeds, but as W1NGE says mostly at lower speeds.

I have had it on a couple of occasions where I have been approaching traffic lights and it is one of those where the lights turn and you are almost committed but not quite, so you firmly apply brakes and not much happens so you have to go that much harder quick to stop before the line and have ended up skidding, looking like a bit of a plank as their are inevitably lots of people about.

Am sure this is a combination of the weight and also the second that you lose when the thing doesn't slow down as you expect initially. When I drive the wife's Range Rover I almost put her through the windscreen the first couple of times I brake.

Is definitely one that keeps you on your toes.

I have mostly has this in the dry, spongy is defiantly the right terms for it, and it catches you out as there doesn't seem to be any consistency with it.

did you ever ask if this was normal at the dealer?

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[bluegrassvroom]

It's raining pretty good later this week - so today it's going in so they can test it during the rain (and get the all-season tires) - i'll let ya'll know how it goes - thanks for all the feedback so far. Sorry to all of you with the same (or similar issues)

 

[hoffa]

This happens to my car periodically as well. I have PSCB on my Taycan 4S.

I haven't quite figured out the conditions in which this occurs, but it is an "oh crap" moment when you're pulling to your garage and you have to stomp on the brakes to get the car to stop! For me it has happened in the summer and winter. Most of my drives are relatively short (15 min?). I've noticed the car likes to polish the brakes before it turns on regen, so I have gotten into the habit of braking a bit harder until regen kicks in.

 

[rpd]

It's raining pretty good later this week - so today it's going in so they can test it during the rain (and get the all-season tires) - i'll let ya'll know how it goes - thanks for all the feedback so far. Sorry to all of you with the same (or similar issues)

I'm experiencing the same issue... any update?

Thanks!

 

[bluegrassvroom]

I'm experiencing the same issue... any update?

Thanks!

they've got it at the shop now. rained pretty good wednesday (?) and they drove it a bit - they didn't experience the spongy brakes but are still checking potential causes thoroughly. They're taking it pretty seriously

do you have the PSCB, @rpd? I'm thinking that's the main thing similar cars have in common

BTW - have a Cayenne loaner. don't love a lot about it - BUT THE REAR VIEW CAMERA isn't this stupid, comically exaggerated/stretched view. Still befuddled why they did that...

 

[rpd]

they've got it at the shop now. rained pretty good wednesday (?) and they drove it a bit - they didn't experience the spongy brakes but are still checking potential causes thoroughly. They're taking it pretty seriously

do you have the PSCB, @rpd? I'm thinking that's the main thing similar cars have in common

BTW - have a Cayenne loaner. don't love a lot about it - BUT THE REAR VIEW CAMERA isn't this stupid, comically exaggerated/stretched view. Still befuddled why they did that...

I have a 2021 Turbo S so I'm pretty sure they come with the PCCB's standard?

But it's raining here in PA and I noticed exactly what your original post described!

 

[bluegrassvroom]

I have a 2021 Turbo S so I'm pretty sure they come with the PCCB's standard?

But it's raining here in PA and I noticed exactly what your original post described!

yeah - i'd make an appointment if i were you. sooner the better. i'll post any resolutions to this board and you can use that to show your people.

here's what i'm not sure some people (including my service advisor??) understand - when this happens, it's NOT like the brakes are being applied and they're light in their braking power. To me, the brake pedal is VERY , hmm..., non-responsive - it sinks in ALL THE WAY and to me- seems like it's not activating the mechanical braking at all. i normally use 10-20%, MAYBE 30% of the brake pedal's potential travel distance. there's no reason i should be pressing the brake pedal IN AT A FULL 100% AND NOT COMING TO A STOP WHATSOEVER.

I'm hoping they can solve this without me stating what i feel i have to do if this continues and can't be fixed - but it's simply not safe and i can't drive a car that doesn't have reliable brakes in all conditions. It's not an annoyance, it's not a preference. It's literally a life and death situation

 

[mas_gts]

I'll add some anecdotal experience in relation to PSCB. This thread jogged my memory. Whilst I was test driving different taycans last year to narrow down on which options to select for my build. I do recall somewhat 'spongy' brakes in the taycan that had PSCB vs the one that had STD. In the end I went with the STD brakes as that was going to be more than sufficient for my usecase, but it did have an impact on my decision making.

I will caveat above as just my personal experience and quite possibly a one-off but thought it was worth mentioning.

Perhaps we should ask if anyone with STD brakes notices this 'spongy' brakes sensation?

 

[rpd]

yeah - i'd make an appointment if i were you. sooner the better. i'll post any resolutions to this board and you can use that to show your people.

here's what i'm not sure some people (including my service advisor??) understand - when this happens, it's NOT like the brakes are being applied and they're light in their braking power. To me, the brake pedal is VERY , hmm..., non-responsive - it sinks in ALL THE WAY and to me- seems like it's not activating the mechanical braking at all. i normally use 10-20%, MAYBE 30% of the brake pedal's potential travel distance. there's no reason i should be pressing the brake pedal IN AT A FULL 100% AND NOT COMING TO A STOP WHATSOEVER.

I'm hoping they can solve this without me stating what i feel i have to do if this continues and can't be fixed - but it's simply not safe and i can't drive a car that doesn't have reliable brakes in all conditions. It's not an annoyance, it's not a preference. It's literally a life and death situation

Exactly the same braking sensation I am getting today. I first noticed it trying to come to a complete stop and REALLY had to push as hard as I could on the brake pedal.

I won't drive it in the rain until I get it in the shop. I've never experience this issue in dry conditions.

Thanks for your original post!

 

[notsofast]

I also noticed that the PSCB calipers on the 2020 4s were significantly larger than mine, something my sales advisor had no explanation for. I don't know what to do at this point, this is a really bad safety issue that Porsche doesn't seem to want to rectify.

IIRC the PSCB brakes were changed for MY2021. They went from 10 piston to 6 piston calipers in the front. Supposedly the smaller ones were sufficient and reduce unsprung weight. That's why yours are smaller.

 

[bluegrassvroom]

EMERGENCY BRAKE - is there one we can apply while driving if this happens?

i came across a post from a while back, someone (UK?) saying if they hadn't applied the E-Brakes they would have hit the car in front of them. I direct messaged that person to ask HOW TO APPLY THEM (no response to DM)

do ya'll know? Am I an idiot - did i overlook a lever, button, something easy? can it be done while moving?

 

[rpd]

Exactly the same braking sensation I am getting today. I first noticed it trying to come to a complete stop and REALLY had to push as hard as I could on the brake pedal.

I won't drive it in the rain until I get it in the shop. I've never experience this issue in dry conditions.

Thanks for your original post!

So I was reading some very old Porsche threads where drivers were talking about PCCB problems in the rain or when wet.... seems like its an undocumented feature of them .

Anyone with PCCB's experience a similar issue? Maybe I'll start a separate thread...

 

[Genau]

EMERGENCY BRAKE - is there one we can apply while driving if this happens?

https://www.taycanforum.com/forum/t...rake-while-the-car-is-moving.9120/post-130203

 

[Lars]

EMERGENCY BRAKE - is there one we can apply while driving if this happens?

i came across a post from a while back, someone (UK?) saying if they hadn't applied the E-Brakes they would have hit the car in front of them. I direct messaged that person to ask HOW TO APPLY THEM (no response to DM)

do ya'll know? Am I an idiot - did i overlook a lever, button, something easy? can it be done while moving?

I think this is what you are after. I found it in one of the threads I remembered reading before.

 

[Tsingtao]

I think this is what you are after. I found it in one of the threads I remembered reading before.

It would be beyond awesome if someone on this forum -- probably with a leased Taycan -- would try the emergency procedure outlined above (maybe at about 70 mph?) and video what happens along the way.

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