Bleeding brakes advice

My car is an Audi A8 4E and recently I installed new pads and discs all round. While doing the work I noticed that the short brake line connected to the front caliper from the flexi line was corroded. Thinking it may be an inspection failure I decided to replace this short pipe on both fronts. They were that corroded they broke when I removed them. The flexi pipe was capped off with a bleeder screw so fluid did not escape. I don't have the tools to bend pipe so bought original from Audi, less then £9 for each so very reasonable. Then I had to wait as no UK stock. In the meantime I cleaned the calipers. Parts arrive, attach the front calipers, bleed them. And this is where I may have messed up... The brake fluid reservoir went just below the min and I may have air in the master cylinder, and I do have a spongy pedal. Reading the general internet most say to remove the MC and bench bleed. Reading VW/Audi forums about master cylinders people have just bleed on the car with no problems. The ABS is ESP 5.7 in the A8 4E. So should I just connect up my pressure bleeder and flush the system and few times with new fluid to remove the air?

The only brake bleeding info from Elsa is below, and there's no mention of pre priming a new MC before installation.

Unlike ESP 5.3, ESP 5.7 does not incorporate hydraulic pump -V156-. It is therefore not necessary to bleed the pre-charging pump with the diagnostic tester.

Click to expand...

Just to add for Uwe and RT, second time I've used VCDS for rear electronic brake work/pads on the 4E with no problems at all

mattylondon said:

So should I just connect up my pressure bleeder and flush the system and few times with new fluid to remove the air?

Click to expand...

I would start there and if it call it good if it fixes the sponginess.

If not, you could try running the pump via Output Tests (not 100% sure whether the module supports it though), and another tactic is to find a slipper surface such as a gravel road or wet grass, where you can force the ABS into full activity without tearing up your tires.

-Uwe-

Bleed brakes manual strategy & while the car is running at idle.

Thanks for the reply Uwe and Jack. I'll have time this coming weekend to get the system bled. As for the output test, I don't want to try that as the 4E gets that odd error code in the ABS module. Other A8 owners just can't clear it.

http://wiki.ross-tech.com/wiki/index.php/00003

Gravity bleed sometimes help things work out well........

Pressure bleed the system at 2 bar.
In this order.
1. n/s/f
2. o/s/f
3. n/s/r
4. o/s/r
Then you will have a perfect pedal.

Just something that came to mind while I was reading this thread.. does anyone think a pneumatic brake bleeder would work on these cars?
I used to use mine on my older Porsches and it was a godsend.

Thoughts?