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

[bluegrassvroom]

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

Thanks Lars - exactly what i was looking for. It sounds like this is what one poster did in a post a few months ago when their car lost braking ability. I'll let you know if i ever have to utilize this. My car's in the shop now for this issue. Hopefully it never happens again...

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[Nmoranda]

I picked up my car and it dumped rain for the next week straight. I text my SA and dramatically said “did Porsche forget brakes on my car, I’m going to die”. It hasn’t rained since but those 4-5 days weren’t fun.

 

[garlokleung]

Hi, have you checked this recall for the brake?
https://static.nhtsa.gov/odi/rcl/2021/RCLRPT-21V697-6539.PDF

 

[bluegrassvroom]

so an update - Porsche had my car about a week. It rained steadily several days they had it - on top of them testing it thoroughly around the dealership, they had two different advisors/technicians drive it home to see if they could reproduce the issue (i'd let sixteen people drive it home if they could fix it). They never could.

They DID take it seriously and did a litany of checks and tests to try and figure it out - and if I were in their shoes, not being able to reproduce it - I'm not sure what I'D DO if someone told me this but the techs never experienced it

Fast forward about a week - it rained pretty good here the other day. Not POURED, but STEADY rain for hours and hours.

I went to pull into a driveway to turn around - couldn't have been going more than 5 or 8 miles an hour, if that. Car simply - wouldn't stop. period. went at LEAST half a car length past where i planned on it. Driveway was clear - but what if.... another car was there, or there was a garage there, or a grandma walking with a baby stroller or.... for a car to go WAY PAST your predicted stopping point WHEN GOING VERY SLOWLY - YIKES.

@02bluesuperroo - i felt your pain reading your posts - but i initially thought OH, THAT'S SERIOUS BUT NOT NEARLY AS BAD AS IT HAPPEINGIN ON THE ROAD AT A LIGHT - well, let me apologize - because after having it happen, although it HOPEFULLY wouldn't cause anyone's death, it could CERTAINLY end up with tens and tens of thousand in property damage AND some AWFULLY hurt pedestrians... or a combination of the two
[per posting at: https://www.taycanforum.com/forum/t...e-have-my-family-sue-porsche.9048/post-128804 ]

So, unfortunately, the story continues. I don't think hosing down tires, driving around the block, hosing down tires, driving around the block, etc etc will repeat it for the dealer (although i hoped it would - that was my initial idea for them). Hopefully i can get it to them on the next super rainy day and force someone to ride around with me until it happens. Although, i guess, technically, they'd need to be driving.

 

[bluegrassvroom]

I picked up my car and it dumped rain for the next week straight. I text my SA and dramatically said “did Porsche forget brakes on my car, I’m going to die”. It hasn’t rained since but those 4-5 days weren’t fun.

did your SA ever come up with reasons your Car was sold "without brakes"? That made me chuckle - but for anyone who's experienced the issue - THAT'S WHAT IT'S LIKE. It's like they removed the Taycan brakes and installed a POWER WHEELS CAR'S BRAKES

I wonder if we can 'downgrade' our brakes and get our $3490 back and have functioning brakes???

 

[mrdrummergoalie]

My 2 cents... I notice the same thing, particularly after a carwash. It is consistent and reproducible. Oh, and more than a bit scary. Regular Brakes.

 

[TaycanHero]

I know this is anecdotal as my driving time is 15 miles vs five figures for actual owners, but...

Curiously I have only ever driven a Taycan 4S CT once for a test drive. It wasn't raining but roads were wet. High single digit Celsius air temperature.

Came up to some traffic lights on a 70mph road. I obviously applied brakes in good time as is normal, but I was taken by surprise where the brakes felt mushy and I must have travelled about 1.5m farther than expected. This did not happen anywhere else on the test drive.

Thankfully the car ahead of me had enough space, but it could have been embarrassing not least with the test drive plates on show in the front window ?

I got back to the dealer thinking: why does my Mercedes EQA AMG Line, which makes no claims to its driving performance, have superior stopping power?

It weighs almost the same as the Taycan as well, and bounces around the road like an obese elephant.

Initially I thought maybe I wasn't applying the brakes with enough force, but on reading this article and others on the Taycan forum*, I wonder if there is a bigger issue for some cars, which is why other owners are not reporting these problems.

It could be very dangerous as the OP explains - and have Porsche acknowledged there might be a problem?

*The other thread on this forum about this issue explained for some Taycan's, the brakes need bleeding. It is difficult to diagnose, but "air" is trapped and that needs to be bled, which then provides razor sharp braking once again ?‍

 

[Toodal00]

I know this is anecdotal as my driving time is 15 miles vs five figures for actual owners, but...

Curiously I have only ever driven a Taycan 4S CT once for a test drive. It wasn't raining but roads were wet. High single digit Celsius air temperature.

Came up to some traffic lights on a 70mph road. I obviously applied brakes in good time as is normal, but I was taken by surprise where the brakes felt mushy and I must have travelled about 1.5m farther than expected. This did not happen anywhere else on the test drive.

Thankfully the car ahead of me had enough space, but it could have been embarrassing not least with the test drive plates on show in the front window ?

I got back to the dealer thinking: why does my Mercedes EQA AMG Line, which makes no claims to its driving performance, have superior stopping power?

It weighs almost the same as the Taycan as well, and bounces around the road like an obese elephant.

Initially I thought maybe I wasn't applying the brakes with enough force, but on reading this article and others on the Taycan forum*, I wonder if there is a bigger issue for some cars, which is why other owners are not reporting these problems.

It could be very dangerous as the OP explains - and have Porsche acknowledged there might be a problem?

*The other thread on this forum about this issue explained for some Taycan's, the brakes need bleeding. It is difficult to diagnose, but "air" is trapped and that needs to be bled, which then provides razor sharp braking once again ?‍

can you send me the other forum with this info on it. im having a hard time finding it .thank you

 

[TaycanHero]

can you send me the other forum with this info on it. im having a hard time finding it .thank you

Sure, it's here:

https://www.taycanforum.com/forum/threads/there’s-a-goat-stuck-in-my-front-brakes.8523/

 

[Windpower]

I went to pull into a driveway to turn around - couldn't have been going more than 5 or 8 miles an hour, if that. Car simply - wouldn't stop. period.

Can you tell us which mode you were in? Normal or Sport?
Also, which regen mode were you in? Off, On or Auto?
The reason why I ask is that the braking acts differently in the different modes. I run in Sport and Recoup On. When I brake, the motor is mostly used to slow the car down and it takes some time to get used to.

 

[bluegrassvroom]

Can you tell us which mode you were in? Normal or Sport?
Also, which regen mode were you in? Off, On or Auto?
The reason why I ask is that the braking acts differently in the different modes. I run in Sport and Recoup On. When I brake, the motor is mostly used to slow the car down and it takes some time to get used to.

i run in Normal mode, sport suspension, recoup OFF

i've had it 6-7 months now - it only does this in heavy rains - never once when dry

 

[atebit]

Take it to the dealer, there is a bulletin on this. I’ve had mine in once already, the “phase I” solution (flush/fill/bleed) only worked for less than six weeks, so it’s going back for a total brake overhaul.

 

[bluegrassvroom]

**UPDATE AFTER GOING TO PORSCHE SERVICE**

SO - update - went to the dealer earlier this week. Was predicted to POUR all day. They wanted to ride with me and see what they could observe when the brake issue reared up

while i was waiting for the right person to ride along with me - it was monsoon-ing outside. Of course once we got ready to hop in the car - it was 'just' lightly raining. Normally the brakes ONLY act up in medium to heavy rain.

we drove around a good 30 minutes - it kinda sorta did it once or twice - then the rain started letting up and i KNEW i was doomed - i'd have wasted a trip there and not be able to reproduce the brake issue

a block before returning to the dealer - we took a swing through a parking lot. it had some standing water - so i drove through it, and afterwards - NO BRAKES!!!!! Ok, ok, not quite 'no brakes' but at least the brake issue happened.

it was also a pretty serious puddle/pond - i'd imagine up to 3" deep, about the length of the car, so i could stop in it and let the car marinate in the water...

it was VERY reproducible - sometimes if i went through the water at 5-7 mph, the brakes wouldn't work correctly just 10 feet past the water. Sometimes it would brake fine then, we'd do a U-Turn, head back to the water, slow down to do another U-Turn and BRAKES ACTED UP AT THAT STOP (say 50-60 feet after the puddle). Sometimes the brakes did work at the puddle and also for the U-turn stop.

We must have done it a dozen or so times myself, and the Service Rep (manager?) did it several times as well. - HERE ARE THE OBSERVATIONS MADE when we knew it was coming. when road driving, even in heavy rain - it didn't happen all the time - normally once per trip in the heavy rain (in say, 10-12 slow downs) - so it was difficult to observe what was happening (when you're worried about staying alive and not wrecking) but when there's two peopel and you knwo it's about to happen, you can notice:

-THE REGENERATIVE BRAKING IS NOT TRIGGERING, it is solely mechanical braking

-IT IS NOT MECHANICAL BRAKING like the first 1, 2, 3 times when you drive your car (when you first hop int he car, your first brake or two or three is 100% mechanical, but the brake pedal feels the same as when regen is on, AND you know, the car actually stops)

-The sound is like the sound of your brakes TRYING to brake you after a car wash but slipping and not gripping properly

My new description of the issue: imagine if the first 30% of a NORMAL brake pedal push is FULLY regen braking, then the next 30-40% is a combination of some regen, some mechanical braking. And the last 30% of the brake pedal gives you 100% mechanical braking. Imagine there are servos or something that give you that brake pedal resistance feel - the device actually making the brake pedal push back against your foot. imagine there's one for the regen braking, and another for the mechanical braking. They normally work in a synchronized way where you feel a constant pressure when applying the brakes and engaging the brake pedal. OK, now imagine, something told the REGEN braking system - to 1) do not apply regen braking and 2) do not apply resistance to the brake pedal for that travel distance that is normally 'regen braking' brake pedal usage. so the brake pedal has no resistance the first 30-50% of it's travel distance. that's what the feeling is when this issue is happening: there is no regen braking AND there is no 'brake pedal feel' during that portion of the brake pedal travel

~ ~ ~ ~ ~ ~

As repeatable as it was that day - the service advisor wanted to take ANOTHER Taycan out (4S, like mine, PSCB, like mine, and same wheels even) - THE OTHER TAYCAN PERFORMED THE SAME IN THE SAME SITUATION. YES, A DIFFERENT TAYCAN ON THEIR LOT DID THE SAME THING AND HAD THE SAME BRAKING ISSUES IN THAT PUDDLE

I felt vindicated - A) I wasn't crazy [at least in 'imaging' this happening] and B) it's NOT JUST ON MY CAR

~ ~ ~ ~ ~ ~

I was told there are sensors in the wheel wells for different reasons -for suspension, braking, etc -

one could HYPOTHOSIZE that something somewhere was telling the Taycan NOT TO USE REGEN BRAKING. but for whatever reason, it wasn't telling the mechanical brakes "Hey, do what you normally do when the car is first turned on"

who knows why, who knows what -and nothing beyond these observations is known. I could conjecture, i could imagine, but i don't know, the service advisor didn't, no telling if anyone at Porsche does at this point.

I'm ok with the car deciding, based on telematics and sensor readings and reading tea leaves to NOT engage the regen brakes. BUT - the car needs to engage the mechanical braking like it does when first turned on and give the driver the same feel and the same stopping ability when using 100% mechanical braking. But as-is, it's dangerous. It's dangerous when going through a puddle at 5mph (it was IMMEDIATELY before a main road, and more than once the car stopped past the intended stopping target (sidewalk distance) and went right up to or into the street - and we knew it was going to happen)

Take that same issue - brakes giving the car and driver only a fraction of the stopping power - apply it randomly during wet street driving, and in 1 out of 12 wet stops, you get zero regen braking and your car only gives you a fraction of the physical mechanical braking. It might be when you're trying to stop at a light. It might be when you're trying to park in a spot (imaging overshooting your parking spot 1 of 12 times - by 5-10 feet). It might be when you have to brake in an emergency.

SO far they've taken this seriously and responded appropriately. Hopefully they can come up with a fix, because right now i don't feel safe in this car in the rain, and i wouldn't recommend other people driving it in the rain either

 

[Nmoranda]

Thanks for the update. It rarely ever rains here so I haven’t experienced it again. My dealership wasn’t aware of anyone else with the issue. I’m going to follow your journey here if you don’t mind updating as you know more.

 

[luuk]

Today, after taking my car through a car wash (self-service pressure guns), where I sprayed at the wheels/brake discs, I experienced the same brake failure issue described in this thread immediately after leaving the car wash. The problem disappeared after 2 brake applications at relatively low speeds. But man is this concerning and absolutely unsafe.

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