Hi there. Got an A6 C8 2019

In may this year the message "Brake servo restricted. You can continue driving. Please contact workshop "

Took 2 weeks for audi dealership to book me in, meanwhile I was driving the car 150 miles a day, with a very bad braking: the car shaking when braking,  brake pedal shake as well.

I changed the sensor, and I could feel the car shaking when braking over 50 miles/h from the moment i drive off from dealership. Book it in again, audi dealership said I need to change the discs and pads.

I went with a private service. After changing them, the car brakes just fine. Roughly 2 weeks after and over2k miles done , the brake shaking appears again.

Went to a different private service, they said the same:i need to change the discs and pads, maybe the other where bought broken,  it happens they said. Change them again, couple of weeks later and over 2k miles done same issue.

I'm going to audi dealership and they said because i haven't used genuine audi parts that happened . So here I am, change the discs and pads the 3rd time in 4 months.

2 weeks later, and over 2k miles done? Yes, same problem. 

Is anyone in here heard something like this ?

Hello Sebastian,

Welcome to the forum, and sorry to hear about you ongoing issue. 
Logic would suggest that all the discs and pads just cannot be faulty. 
My stab at it:- 

Sticky callipers and/or slider pins. 
Kind regards,

Gareth. 

Sorry to hear about the brake issue.

About 18 months ago I also had the “Brake servo restricted. You can continue driving. Please contact workshop” message.  I took the car to my local Audi dealer who were fully aware of the problem - it seems the sensor going wrong is fairly common and it would be fixed under warranty.

They did ask me how long I had driven the car with the fault. They said the fault message wasn’t correct and that you can only press the brake pedal a certain number of times before the “ABS module” gets “wrecked”. Fortunately, I had only driven about 10 miles so all was fine once the sensor was replaced.

However, it seems you perhaps drove your car for some weeks with the sensor fault. If you have changed pads and discs many times and the brake shaking fault comes back it would seem unlikely they are the cause of the fault. 

In view of extended driving time with the original sensor fault might I suggest that the ABS module is looked at - maybe a different option to changing pads and discs yet again?