also, wenn Ihr ASC+T System habt, da kann man lange machen, bis das entlueftet ist ohne Spezialwerkzeug.
Hier eine englische Beschreibung:
Bleeding brake system with ABS/ASC+T
34 00 048 Bleeding brake system with ABS/ASC+T
Note:
Conform with filling and bleeding procedures when replacing or repairing the
- Tandem-brake master cylinder
- Hydraulic unit ABS/ASC+T
- Accumulator ASC+T
- and components which are installed between these units.
The procedures of "Bleeding brakes with ABS",refer to 34 00 047 are also applicable for ASC+T vehicles when performing other jobs on the braking system (e.g. replacing brake calipers).
Caution!
Note "General Data", refer to 34 00 ...
1. Connect bleeder on expansion tank
Note:
Check relevant Owner's Manual for each device.
Charging pressure should not exceed 2 bar.
2. Bleed braking system in advance
Connect bleeder hose with bottle to rear-right brake caliper.
Open breather valve and flush brake system, flush volume
approx. 50 cm 3 (brake fluid must emerge without bubbles).
Close bleeder valve.
Bleed brakes in the same manner at left rear, right front and left front.
3. Bleed hydraulic unit ABS/ASC+T
Connect BMW Service Tester to vehicle diagnosis connector.
Select number 50 "Teves Slip Control System" from control-unit overview, followed by number 5 "Special Functions" from the menu and finally number 1 "Bleeding Routine for ASC+T".
4. Bleed braking system
Connect bleeder hose with bottle to rear-right brake caliper.
Open bleeder valve and flush braking system while operating brake pedal as far as it will go at least 10 times (escaping brake fluid must be free of air bubbles).
Keep brake pedal pressed down, close bleeder valve and
release brake pedal.
Bleed brakes in the same manner at left rear, right front and left front.
Installation:
Use dust caps on bleeder valves.
5. Bleed accumulator ASC+T (only vehicles up to 09.93)
Remove liner from inside of front-left wheel house.
Connect bleeder hose with bottle to bleeder valve
(accumulator).
Caution!
Pressure in accumulator will be approximately 120 bar.
Carefully open bleeder valve. Start bleeding routine in selected menu item of special functions (BMW Service Tester) and flush accumulator until escaping brake fluid is free of air bubbles.
If necessary, repeat bleeding routine several times.
Close bleeder valve.
Install dust cap.
Install liner on inside of wheel house.
6. Remove bleeder
Check and, if necessary, correct brake-fluid level.
Screw cap on expansion tank (ensure that rubber seal (1) is installed in cap).
with drawings here
http://adkusters.hobby-site.com/TIS%.../34_00_048.pdf
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Important tip for bleeding ASC+T
Bleed hydraulic unit ABS/ASC+T:
On my 12/1992 750iL with ASC+T, I had no idea how to access the bleeder screw on top of the hydraulic control unit to bleed the hydraulic system. I spent two hours trying to just touch it by reaching under the master cylinder, but there's a MUCH easier way!
Release the plastic clips on the two large black plastic electrical connectors along the left side (near the diagnostic connector) and lift them up and forward. Then you'll have clear access to the bleeder screw. You can just get a short 11 mm wrench on it to crack it loose, but first make sure you attach the pressure bleeder and the bleeder hose and the engine is running. You must bleed this first before the rear brakes.
I followed the steps described in the Bentley manual and it worked out fine.
Another warning/tip: when you bleed the front breaks by pumping the brakes, watch the fluid level VERY CAREFULLY! The fluid drains out in only 5-10 pedal pumps. I ran out of brake fluid and had to start over twice before I figured this out. The whole process of bleeding the brake system - I had to because I disconnected the master cylinder while replacing all the hydraulic hoses - takes about two hours doing it alone.
I had removed the master cylinder to gain access to replace some hydraulic hoses. After installing the MC, I didn't bleed it. Instead I just followed the Bentley manual for pressure bleeding the hydraulic control unit, then rear brakes (3 steps: regular pressure bleed, pumping pedal pressure bleed, ASC+T switch on/off while rear wheels spinning), then front brakes. This worked fine.
Actually, I have replaced many MC's and have never bench or car bled them. I just fill it with fluid and bleed the brakes. Not saying this isn't ever necessary, but has always worked for me.
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An even easier way to bleed the ASC+T. Put the rear on jack stands and run the car in gear. It senses "wheel slip" and engages the traction control like mad. Bleeding is done in a matter of seconds.
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