Ive found some info in the technical manuals, it does say each caliper needs bleeding 5 times!! This ties in with what Maxitrol said.
Pre-bleed:
- Connect Brake filler/bleeder unit VAS 5234 .
Bleeding sequence:
1 - Bleed left front and right front brake caliper together
simultaneously
2 - Bleed left rear and right rear brake caliper together
simultaneously
- With bleeder bottle hoses attached, leave bleeder valves
open long enough that brake fluid exits without bubbles.
The hydraulic unit must be bled again with tester VAS
5051 via function "Basic settings" .
Initiate basic setting (to bleed brake system):
VAS 5051 , connecting and selecting functions 45-3,
Connecting Vehicle Diagnostic, Testing and Information
System VAS 5051 and selecting functions .
- Then bleed brake system
Bleeding (normal):
Adhere strictly to work sequence when bleeding brake
system.
- Connect Brake filler/bleeder unit VAS 5234 .
- Open bleeder valves in prescribed sequence and bleed
brake caliper.
1 - Left front brake caliper
2 - Right front brake caliper
3 - Left rear brake caliper
4 - Right rear brake caliper
Use suitable bleeder hose. It must fit tightly on bleeder
valve so that no air can enter brake system.
- With bleeder bottle hose attached, leave bleeder valve
open long enough that brake fluid exits without bubbles.
Subsequent bleeding
A second technician is required to assist:
- Depress brake pedal forcefully and hold.
- Open bleeder valve at brake caliper.
- Press brake pedal down onto stop.
- Close bleeder valve with pedal held down.
- Release brake pedal slowly.
This bleeding procedure must be performed 5 times
per brake caliper.
Bleeding sequence:
1 - Left front brake caliper
2 - Right front brake caliper
3 - Left rear brake caliper
4 - Right rear brake caliper
A road test must be performed after bleeding. During
this, at least one ABS regulation must be performed!
Jas