AR42.10-P-0009T Bleed Brake System Without Star Diagnosis
Bleed Brake System Without STAR DIAGNOSIS
DANGER:
- Risk of injury. When working on the SBC brake system, body parts may be jammed or crushed and skin and eye injuries may result due to brake fluid escaping under high pressure.
- Disable the SBC self-test
- Risk of poisoning from swallowing brake fluid. Risk of injury from brake fluid coming into contact with skin and eyes.
- Pour brake fluid only into suitable and appropriately marked containers. Wear protective clothing and eye protection when handling brake fluid.
- Risk of death. Death may result if vehicle slips or topples from the lifting platform.
- Align vehicle between the columns of the lifting platform and position the four support plates at the lifting platform support points specified by the vehicle manufacturer.
CAUTION:
- See brake fluid notes
- See notes on repairs to brake system
- Brake lining replacement and brake fluid change must not be carried out simultaneously.
- Before working on the SBC brake system the sequence of the SBC self-test must be prevented, as this leads to the brake pistons moving out automatically.
- When working on the SBC brake system the brake pedal must not be pressed under any circumstances as this leads to the brake pistons moving out automatically. Inadvertent operation of the brake pedal must be prevented reliably by suitable measures.
- When working on the SBC brake system no persons or animals must stay in the vehicle.
NOTE:
- Before starting work it is absolutely essential to read through the complete work description as the operations have to be completed in rapid succession. To carry out the operations correctly a second person must be present as within the work procedure certain signals cannot be seen by one person
- If the work procedure is revised or if the time requirements cannot be adhered to, the operations cannot be carried out correctly.
1 Position the vehicle on the two-pillar or four-pillar lifting platform
2 Open driver-side side window
3 Switch off all the vehicle's electrical consumers and remove the key from the ignition switch
NOTE: Vehicles with code (889) Keyless Go: Press starting-stop button repeatedly until the ignition is switched off.
4 Unlock engine hood and close the vehicle doors
5 Open engine hood
6 Raise the vehicle until all the wheels can be rotated freely
7 Close vehicle doors and allow the vehicle to be locked globally for min. 30 seconds (t1)
NOTE:
- Vehicles with code (889) Keyless Go: remove Keyless Go cards or key from the vehicle and store outside of transmitter range (for at least 2 minutes).
- During this time the run-on of the SBC brake system elapses.
8 Unlock vehicle
NOTE:
- From now on the brake pedal must not be pressed anymore.
- An SBC self-test may proceed.
9 Connect a battery charger to the rear on-board electrical system battery and switch on
NOTE:
- Connect the negative terminal of the battery charger to the body ground (not to the negative terminal of the battery) so that the battery control module detects the charging of the battery.
- It must be possible to raise the vehicle with the battery charger connected.
10 Connect brake fluid replacement unit
NOTE:
- Pay attention to manufacturer's operating instructions.
- It must be possible to raise the vehicle with the brake fluid changing equipment connected.
- The brake fluid changing unit must reach a pressure of 2 to 3 bar.
- Brake fluid replacement unit
Bleed front brakes
11 Remove the front wheels
- If there is difficult access to the bleed screws
12 Switch on brake fluid replacement unit
13 Connect bleed bottle to the bleed screw of the front left brake caliper (1). Open, close bleed screw
NOTE: Leave bleed screw open until new brake fluid flows through the bleed bottle hose free of bubbles.
14 Connect bleed bottle hose to the bleed screw of the front right brake caliper (2). Open, close bleed screw
NOTE: Leave bleed screw open until new brake fluid flows through the bleed bottle hose free of bubbles.
15 Switch brake fluid replacement unit depressurized
NOTE: Switching off the brake fluid replacement unit is not sufficient, the residual pressure is only reduced by disconnecting the brake fluid replacement unit.
16 Fit front wheels
- When the front wheels are removed.
Bleed rear brakes
17 Remove right rear wheel
- In the event of difficult access to the bleed screw.
18 Connect bleed bottle hose to the bleed screw of the rear right brake caliper (3)
NOTE: Keep ready a suitable tool for opening the bleed screw. Do not open the bleed screw yet.
19 Ignition On (Z2)
NOTE: Through the open side window. Vehicles with code (889) Keyless Go : Do not activate any Keyless-Go functions for the following operations.
20 Switch off ignition (Z0), wait for 1 to 5 seconds (t2) and switch ignition on again (Z2)
NOTE: Do not start engine! The ignition remains switched on for the further steps.
21 Rotate left rear wheel quickly and evenly in the running direction
NOTE: Rotate wheel for min. 3 seconds (t3) (1 to 2 revolution/s (n)), then bring the wheel to a standstill.
22 Rotate left front wheel quickly and evenly in the running direction
NOTE:
- The left front wheel must be rotated max. 60 seconds (t5) after the left rear wheel Rotate wheel (1 to 2 revolution/s (n)) until it is braked automatically.
- The stop lamps flashing on and off 3 times confirms successful activation, the brake fluid change routine is started. The front brake pads are applied several times.
- Steps 23 and 24 must be carried out within 40 seconds of the stop lamps finishing flashing on and off 3 times
23 Switch on brake fluid changing equipment
NOTE: Subject the SBC brake system to a pressure of 2.0 to 3.0 bar.
24 Open bleed screw of right rear brake caliper (3)
NOTE:
- Extremely high pressure in the bleed bottle hose, secure or hold it to prevent it from slipping off.
- The high-pressure pump only starts to deliver after 40 seconds have elapsed since the flashing of the stop lamps.
- The bleed screw must be opened within the 40 seconds, otherwise the brake fluid change routine is terminated, do not open the bleed screw anymore. Start again with step 20.
25 150 seconds (t6) after stop lamps flash on and off 3 times (step 22), close the bleed screw of the right rear brake caliper (3)
NOTE: The procedure of the brake fluid change routine ends automatically in the event of problems the brake fluid change routine can be terminated prematurely by closing the bleed screw. It is absolutely essential to carry out steps 35 to 37 before repeating the brake fluid change routine.
26 Connect bleed bottle hose to the bleed screw of the left rear brake caliper
27 Remove left rear wheel
- In the event of poor access to the bleed screw.
28 Open, close bleed screw of left rear brake caliper (4)
NOTE: Leave bleed screw open until new brake fluid flows through the bleed bottle hose free of bubbles.
29.1 Remove rear part section of lower engine compartment paneling
29.2 Remove bottom part of rear noise encapsulation
30 Remove cap on clutch housing and open, close bleed screw of central clutch operator (5)
NOTE: Leave bleed screw open until new brake fluid flows out free of bubbles.
31 Fit cap to clutch housing
32.1 Install rear part section of lower engine compartment paneling
32.2 Install rear bottom part of noise encapsulation
33 Switch off brake fluid replacement unit and disconnect at brake fluid reservoir
NOTE: Switching off the brake fluid replacement unit is not sufficient, the residual pressure is only reduced by disconnecting the brake fluid replacement unit.
34 Fit rear wheels
- When rear wheels are removed.
End the brake fluid changing routine
35 Get into the vehicle
NOTE: The brake pedal must not be operated.
36 Ignition off (Z0), press the brake pedal rapidly and with maximum foot force after 1 second (t7)
NOTE:
- This checks the bleed status of the left front brake circuit.
- A slight pressure pulse must be noticeable at the brake pedal.
- Should this not be the case, carry out step 37 nevertheless.
37 Release brake pedal, after 1 second (t7) press the brake pedal quickly and with maximum force until the brake pedal is pushed back
NOTE:
- This checks the bleed status of the right front brake circuit.
- The brake pedal is pushed back by the SBC system by approx. 4 to 10 mm.
- If the brake pedal was pushed back twice as described in steps 36 and 37 the process is completed successfully.
- Repeat bleeding procedure a maximum of once as of step 7, otherwise, bleed brake system using STAR DIAGNOSIS.
38 Disconnect battery charger.
39 Start the engine, depress brake pedal 5 to 10 times, switch off engine and switch on ignition
NOTE: If bleeding is successful no error message appears in the instrument cluster, otherwise, repeat bleeding procedure a maximum of once as of step 7, if the error message was erased the bleeding procedure was successful. If the error message continues to appear in the instrument cluster, carry out steps 7 and 8, otherwise, bleed brake system using STAR DIAGNOSIS.
40 Check brake fluid level in brake fluid expansion reservoir and correct if necessary
CAUTION:
- Only tighten the brake fluid reservoir cap slightly.
- If the brake fluid reservoir cap is tightened excessively, problems with the venting of the brake fluid reservoir may occur.