2021 Porsche Taycan Brakes Problems

On September 5th I was driving my 2021 Taycan 4S on my way to the Gym at 4:15 am, at that time there hardly any traffic. As am merging on the 101 southbound at the nearest on ramp everything seemed ok, as am driving along at 60-65 mph, I came to a downhill and the car was gaining speed, I stepped on the brake pedal to slow it down and to my surprise the brake pedal went all the way down to the floor! I had no brakes and gaining speed, my first thought was if the brakes had failed I would either crash the car against the freeway sidewalks or try to find a place where I can crash without hurting other drivers, fortunately I kept on pressing the brake pedal and it built up some pressure to slow it down but not to stop it, I kept my cool, but I was shaking knowing that I had no brakes! after a few miles the car was slowing down and was able To get off the freeway and pulled into my gym’s parking lot that luckily has an uphill and it helped to slow it down to a complete stop. At this point there was no warnings or error on the dashboard until it came to a complete stop, the message read “PSM failure” and to visit the workshop, nothing about the brake failure that had just happened! And it was after 2 hours, the failure occurred at 4:15 am and that did not show up until 6:12 am. I went into my gym to calm myself down after this horrible experience and after an hour or so I went back to my car and that is when I saw the warning, after a while I called Porsche road assistance and left the car where it was because Porsche road assistance couldn’t send a tow truck quickly, I revived a call from the tow truck company at 9:00 am and met them at the location, I explained to the driver what had happened and as he drove the car out of the parking spot brake fluid started to spray,out of the driver side font caliper, and there was a poodle of brake fluid under the car.

The brakes had no air pressure when trying to slow down; Completely Totalled Which then caused a collision into another vehicle; The car had significant damage with inspection by Insurance adjuster and collision team; No warning lights and had been in the Porsche dealership for computer updates prior to incident.

This vehicle is fully electric, and it uses regeneration while braking. With regeneration on, the braking distance is much shorter than without. The driver does NOT have any means to turn regeneration off while braking. In some instances, the first time the braking system is engaged, regeneration does not kick in, and the braking distance is unexpectedly longer than usual. This has always happened after the car was off for a while and only during the first hard braking. I captured a video of one of these instances.

The brakes fail in wet conditions. Porsche Taycan has 2 brake systems- light braking is regenerative braking (converting mechanical energy into electricity) and for heavier braking the mechanical disc brakes take over IN THIS FAILURE SITUATION in wet conditions pressing the brake pedal does VERY LITTLE to slow the car. DURING THESE FAILURE SITUATIONS, there is 0 regenerative braking occurring. Normally if there is 0 regen braking mechanical brakes engage at 1% brake pedal press so the entirety of the brake pedal engages the mechanical brakes. DURING THIS FAILURE SITUATION, the mechanical braking system does not engage early so it does not begin to engage until near the end of the brake pedal travel. DURING THIS FAILURE EVENT, THE MECHANICAL BRAKES ARE ONLY AT MINIMAL STOPPING POWER (+/- 20%). It has been compared to the first stop after getting a car washed– one must ‘jam on’ their brakes in order to get their car to stop, after which it tends to stop well. Cars come from the car wash at 1-3 mph, so 10-20% braking power does not put the user in jeopardy. IN THESE FAILURE SITUATIONS THE PORSCHE TAYCAN only has 10-20% stopping power WHILE TRAVELLING ‘AT SPEED’ ON NORMAL ROADWAYS The first time this happened I was approaching a stop light in traffic. If the turn lane weren’t empty I WOULD HAVE CRASHED into the cars ahead of me; I jerked the car into the turn lane & eventually came to a stop, with the brake pedal pressed in at 100% for the entire time. It happens at speeds from 3-50 mph It HAS been reproduced with myself in the car by Porsche service, and by other people in their cars, it was reproduced on my car AND ALL OTHER TAYCANS ON THE LOT at the dealer – each car did it The dealer has done ‘everything in their power’ but it is still happening. I was told Porsche NA was investigating on their wet track at their Atlanta HQ, but that the cars ‘tested as designed’ No warning messages or errors –the regen braking gauge always shows 0% while this happens

The vehicle would loose braking pressure after a few minutes of driving. This occurred when the vehicle transitions from regenerative braking to standard braking. Dealer states it is a problem with the brake booster.