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

[Archimedes]

Seems to me something is very wrong with your car.

I've never experienced that in 28K miles.

I’ve only got 6500 miles, but I’ve been driving it in the rain a fair bit lately and haven’t had any issues whatsoever either. Would be quite concerning to me though if I did.

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[TaycanCook]

Ive noticed that when I hit a bump while braking (think minor pothole), the brake pedal depresses deeper suddenly. Like the brakes lose pressure and finds pressure at a lower point.

 

[submatrix]

I actually hit this a couple days ago too, for the first time. I was only going a few mph, so not that worrying, but it felt kind of jarring since I was trying to come to stop behind another car and suddenly, instead of the usual regen resistance I'm so used to, it was if there was no regen resistance at all and my foot depressed all the way to the mechanical brakes (or so I have to assume, given what I know about how the Taycan's regen+braking system works).

Not sure exactly what was going on at the time as far as road conditions/wetness goes.

 

[bluegrassvroom]

Darn, I experienced this today for the first time (2020 turbo, no update). Quite scary!

I was at a car wash and used pressure wash especially on the wheels. After turning out of the spot the brakes did nothing until i pressed much further on the brake pedal. Was going very slow but almost hit the car in front of me.

After this, braking worked fine again. Still love my car but wanted to add my experience here in case Porsche can figure out how this happens

now imagine that - but instead of 2mph (3.2 kph) you're going 35-45 mph on a semi busy road with periodic stoplights and all of the sudden - no brakes when you go to slow down

 

[HelpCarsMark]

Had this happen to me after just leaving home in the rain, I wonder if it happens when the system isn't warmed through? I noticed the regen on the dash hardly moved if at all.

 

[800v]

now imagine that - but instead of 2mph (3.2 kph) you're going 35-45 mph on a semi busy road with periodic stoplights and all of the sudden - no brakes when you go to slow down

Yikes! But I have a feeling there are two separate problems reading this thread:

1. The spongy brakes at slow speed in combination with water (and a sharp turn?) seems common and possibly an error in the software/sensor/brake blending/etc. and should be addressed by Porsche. (for example, Luuk and Benji_OOS experienced the same as me)

2. Your situation with the spongy brakes at higher speed seems less common and perhaps some other problem; like the brake fluids need to be flushed (as remarked here).

Of course, I might be all wrong about this

 

[bluegrassvroom]

Yikes! But I have a feeling there are two separate problems reading this thread:

1. The spongy brakes at slow speed in combination with water (and a sharp turn?) seems common and possibly an error in the software/sensor/brake blending/etc. and should be addressed by Porsche. (for example, Luuk and Benji_OOS experienced the same as me)

2. Your situation with the spongy brakes at higher speed seems less common and perhaps some other problem; like the brake fluids need to be flushed (as remarked here).

Of course, I might be all wrong about this

you're wrong. the same thing i experience MAINLY at low speeds going through water and turning sharply, or at a car wash, i also DO experience at higher speeds in heavy rains or jsut after heavy rains when the roads have standing water - as do other people

regardless - is it ok for a $10,000 car to not stop at low speeds? It's CERTAINLY not ok for a $100,000+ car to not stop at low speeds, not to mention at higher speeds- especially after i've documented it with the manufacturer nearly a year ago.

I'm bundling this information and videos and sending it to the NHTSA ( National Highway Traffic Safety Administration in the US) and i'd recommend other people experiencing this do the same thing (to their respective governing automobile safety authorities). Porsche NA has long enough to investigate and respond to me, and have chosen not to, and i've got it documented they're investigating/working on the problem.

sorry not sorry if this involves everyone here getting a serious safety recall on your Taycans...

 

[DerekS]

you're wrong. the same thing i experience MAINLY at low speeds going through water and turning sharply, or at a car wash, i also DO experience at higher speeds in heavy rains or jsut after heavy rains when the roads have standing water - as do other people

regardless - is it ok for a $10,000 car to not stop at low speeds? It's CERTAINLY not ok for a $100,000+ car to not stop at low speeds, not to mention at higher speeds- especially after i've documented it with the manufacturer nearly a year ago.

I'm bundling this information and videos and sending it to the NHTSA ( National Highway Traffic Safety Administration in the US) and i'd recommend other people experiencing this do the same thing (to their respective governing automobile safety authorities). Porsche NA has long enough to investigate and respond to me, and have chosen not to, and i've got it documented they're investigating/working on the problem.

sorry not sorry if this involves everyone here getting a serious safety recall on your Taycans...

Just get your car fixed. Something is wrong.

 

[bluegrassvroom]

i've tried. and tried

they can't find anythign wrong

unless we go through a several inch deep puddle near their lot, and then it happens. each time. in every taycan they've tried it in

they don't know what to do - waiting on Porsche N.A.

 

[bsclywilly]

i've tried. and tried

they can't find anythign wrong

unless we go through a several inch deep puddle near their lot, and then it happens. each time. in every taycan they've tried it in

they don't know what to do - waiting on Porsche N.A.

It sounds like your problem is related to when the mechanical brakes are activated which happens at low speed, and after water is detected (any speed), to clear the rotor surfaces.

Some troubleshooting advice I can give is to determine if your issue is related to your mechanical brakes or not. Next time, at speed, shift in to neutral first then apply the brakes. This will turn off the regen system and you can see if you're getting the same feeling. If it's a problem, then likely you just need to have the brakes bled. If the braking feels firm with normal pedal travel, then likely there is an issue with the brake blending system. There is a brake stiffness learning process that occurs every time you plug in to charge that allows the electric brake booster to learn how much force is required to match the regen and mechanical braking effect, that may not be working properly.

Regardless, I would still insist that your shop bleed your brakes anyways to take out that variable, if they haven't already.

 

[sailboat310]

Like some who have posted on this thread, I had nearly had two rear end accidents today. When I first got my 21 Turbo, I had the spongy brake feel a couple times after a car wash, but after a few hard brakes, it went away. After 11,000 miles, it came back today.

I live in Chicago and we had a pretty bad storm last week, which ironically I had ablsolutely no issues, but now that it is back to the mid-50's today with wet salty snowmelt, I had the spongy brake issue again. When driving to work, once the regen brake switched to the mechanical brakes, there was a loud groaning and shuddering when coming to a stop. So I drove pretty slowly. When trying to enter the highway ramp going probably less than 10mph, the car in front slowed down and I had smash the brakes while it glided then slammed to a halt less than 1 ft from the car ahead of me. Even after that hard stomp on the brakes, I had to stop WAY earlier to accommodate the extended glide then shuddering to a stop.

At lunch, the groaning and shuddering was about half what it was in the morning. The second near accident happened while making a left turn on green arrow, a car from the opposite direction decides to pull a right turn wide right into my lane. I had to stomp the brakes again which led to another glide then full on brakes while the entire car shook and shuddered like it was coming apart. Luckily the car behind me swerved around me.

No matter what I do, this spongy brake feel will not go away. I called the Porsche service center explaining my situation, and all the said was it was fine as long as there is no light showing on the dash. I called to two different service centers and they all said it was normal.

I've tried restarting the car, trying some hard stops, spraying down the wheels again with water (maybe so the car could recalculate the pressure settings) all to no avail. Just want to comment that this only happens at low speed braking, not at high speeds. Waiting to see if the service center can escalate the call so I can get it towed to their service center.... they need some sort of regional approval for that....which sounds kind of fishy.

Anyone find any solutions?

 

[bluegrassvroom]

[snip]

Anyone find any solutions?

unfortunately, not. I just had the major software update (i live a bit away from the dealer, so i don't go in for every minor update)- the dealer was hoping it would fix it. i've NOT DRIVEN it during this snow and ice and rain - been using my wife's Audi SUV - i've only had it about 3 weeks since the service update and haven't had it in the wet conditions that normally precede the brake issue. Told my service advisor if it happened again, i'd call him, then porsche NA, then the NHTSA (USA's car safety regulation governmental group that leads auto recalls) and put in an official complaint. It's a serious, repeatable issue on multiple cars that has gone unfixed. and it may lead to a bad injury (or worse). ANd Porsche NA knows about it and has reproduced it at their facility - and i'm assuming, has deemed it not worth fixing

if anyone wants me to include their contact on the heap of documentation i'm sending to the NHTSA - DM and i will. I'll reference this thread in it.

i';m not threatening or blackmailing Porsche - just letting them know it's a safety issues that has to get addressed AND REMEDIED

 

[sailboat310]

I just had the software update about 8 days ago right before the big storm. I hope the new software has nothing to do with this.....

 

[Archimedes]

I’ve been driving in the rain constantly the past few weeks, including periods of heavy rain and through standing water. I’ve never experienced this issue. Either it isn’t a problem with every Taycan or it happens really randomly/infrequently.

 

[DerekS]

I've been in massively torrential downpours on road trips.

Never have I experienced a loss of braking, and I agree I'd be really upset if I did.

I hope the affected people can get their cars fixed. If your dealer can't do anything, find a better dealer.

Of all the things that are nitpicks or gripes, braking is a massive safety issue and if your car isn't doing it, it's broken.

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