ABS Brake Bleeding: How-To Guide

Hi everyone!

When I was changing the brake fluid in my vehicle, the fluid reservoir of the braking system ran empty (the helper was careless). Now, I have bled the entire system with pressure applied to the reservoir. However, the brake pedal still feels spongy, indicating that there is still air in the braking system, possibly trapped in the ABS.
I read that there are ABS systems where you need to bypass a relay or access them via diagnostics to bleed the air out. What do I need to do with mine?
Printing on the ABS unit: Bosch 0 265 201 043.

I hope you can help me.

Hey everyone,

It's like it's cursed! First, I tried to figure out which ABS it is. But no luck! I couldn't find anything about it, neither in various DIY books nor on the internet. And on the Bosch website http://www.bosch-automotive.com/ecat-online, you get an error message when you click on the hydraulic unit.
Then I tried to get a repair manual from www.erwin.audi.com. A brake repair manual costs 18.50€, which is still affordable.
But: I couldn't find anything on that website for the brakes of my vehicle. And this is what customer service said about it:

erWin wrote:

Unfortunately, we are unable to find a corresponding document for you. We only provide Erwin (siehe Fehlerdatenbank) with IT support and logistical assistance.

Dann wird noch lang erklärt wie man auf der Seite navigiert. Great - thank you!

I'm slowly starting to feel lost. I hope one of you knows something.

Hi,
I once read somewhere that it might help to bleed the braking system with ABS while the engine is running. Maybe it will work.

Best regards from Berlin.
Olli.

Okay, this is getting very speculative, but for the C4 models of the same era, the ABS system could only be activated if it also had the EDS function. So, if the same technology is used in the B4 and C4 models...

Hey guys!

How about venting it to relieve the pressure?

Best regards,

Hi guys!

How about venting it to relieve the pressure?

Greetz

Hello,
Can it also be done without pressure?
Best regards,
Günther.

Thank you for the (even if only small) help!

@ Christians:
I wouldn't be surprised if the same thing is involved.
Kannst du bitte mal den Aufdruck auf deinem ABS ablesen? Steht da auch Bosch 0 265 201 043? Or do you have EDS?

@Troubleshooter:
How about reading?

wolfi_b wrote:

Now I have bled everything with pressure at the expansion tank.

Okay, I finally managed to do it.

Okay, so I bled the system again (without starting the engine or turning on the ignition). And all I did was repeatedly press the brake pedal while bleeding the system – that's the whole trick.