Bleed brake system

AR42.10-P-0010MB

Bleed brake system

10.11.11

 Danger!

Risk of poisoning caused by swallowing brake fluid. Risk of injury caused by brake fluid coming into contact with skin and eyes.

Only pour brake fluid into suitable and appropriately marked containers. Wear protective clothing and eye protection when handling brake fluid.

AS42.50-Z-0001-01A



Notes on handling brake fluid

AH42.50-P-0001-01A



Notes on repairs to brake system

AH42.00-P-0003-01A



The brake fluid expansion reservoir must not be completely drained to ensure that air does not enter the system. If the brake fluid reservoir is completely emptied, the entire bleeding procedure must be repeated.

The brake system can only be bled with two people attending.

1

Remove wiper arms

AR82.30-P-6100M

2

Remove water repellent

 Fastened with 4 expansion rivets.

Pre-ventilation

3

Switch off ignition

4

Reduce pressure in pressure reservoir

 Fully depress brake pedal 30 times.

5

Unscrew brake circuit closure cap (10c) on brake circuit expansion reservoir and fill expansion reservoir when unpressurized

 Do not connect the filling and bleeding unit yet.

6

Connect filling and bleeding device to plug of expansion reservoir and switch on

 Pay attention to manufacturer's operating instructions.

Brake fluid change unit

gotis://B_42/43.2_01

 Bleed pressure approx. 2 bar.

7

Perform the bleed procedure at all brake calipers

 Start at the brake caliper with the longest feed line.

At each brake caliper allow approx. 80 cm3 brake fluid to escape free of bubbles.

If necessary close the bleed screw once or twice in the process in order to create a short-term pressure buildup to force out any hidden air pockets.

 Bleed screw to brake caliper

*BA42.10-P-1002-10G

 Bleed screw to brake caliper

*BA42.10-P-1002-12G

8

Bleed brake booster hydraulic unit via the brake circuit bleed screw (11b)

 Allow approx. 80 cm3 brake fluid to escape free of bubbles.

If necessary close the bleed screw once or twice in the process in order to create a short-term pressure buildup to force out any hidden air pockets.

 Brake circuit bleed screw (11b)

*BA42.50-P-1001-01B

9

Switch off filling and bleeding device and remove cap on brake circuit

Bleeding booster circuit

10

Unscrew booster circuit closure cap (10d) and fill booster circuit expansion reservoir when not pressurized

 Do not connect the filling and bleeding unit yet.

11

Connect filling and bleeding device to booster circuit expansion reservoir and switch on

 Pay attention to manufacturer's operating instructions.

 Bleed pressure approx. 2 bar.

12

Switch on ignition and simultaneously switch off filling and bleeding unit

 The booster circuit pump starts up.

13

When the booster circuit pump has been switched off, fully depress the brake pedal approx. 10 times

 Booster circuit pump starts up again.

14

After switching off the hydraulic unit booster circuit pump again, bleed via booster circuit bleed screw (11a) with brake pedal pressed down

 Carefully open bleed screw (high pressure). Secure bleed hose to prevent it from slipping.

15

Close booster circuit bleed screw (11a) again and slowly ease off brake pedal

 Repeat this procedure until brake fluid emerges free of bubbles (approx. 80 cm3 ).

 Booster circuit bleed screw (11a)

*BA42.50-P-1001-01B

16

Switch off ignition

Bleeding brake circuit

17

Connect filling and bleeding device to brake circuit plug and switch on

 Pay attention to manufacturer's operating instructions.

 Bleed pressure approx. 2 bar.

18

Switch on ignition

 The booster circuit pump starts up. Wait for the pump to cut out: do not switch off the ignition.

19

Bleed brake calipers at the rear axle

 Start at the brake caliper with the longest feed line.

Exert pressure on brake pedal and open bleed screw while fully depressing the brake pedal. Close bleed screw again and gradually release brake pedal. Repeat this procedure until brake fluid emerges free of bubbles.

 Bleed screw to brake caliper

*BA42.10-P-1002-12G

20

Bleed brake calipers on front axle

 Start at the brake caliper with the longest feed line.

Exert pressure on brake pedal and open bleed screw while fully depressing the brake pedal. Close bleed screw again and gradually release brake pedal. Repeat this procedure until brake fluid emerges free of bubbles (approx. 80 cm3 ).

 Bleed screw to brake caliper

*BA42.10-P-1002-10G

21

Bleed brake booster hydraulic unit via the brake circuit bleed screw (11b)

Exert pressure on brake pedal and open brake circuit bleed screw (11b) while fully depressing the brake pedal. Close brake circuit bleed screw (11b) again and gradually release brake pedal. Repeat this procedure until brake fluid emerges free of bubbles (approx. 80 cm3 ).

 Brake circuit bleed screw (11b)

*BA42.50-P-1001-01B

22

Switch off ignition

23

Switch off and disconnect filling and bleeding unit

24

Reduce pressure in reservoir by fully depressing brake pedal up to 30 times

 While pressing the brake pedal, check the fluid level in the expansion reservoir; stop pressing brake pedal and extract brake fluid, if necessary.

25

Correct brake fluid level in expansion reservoir of booster circuit

 Fill booster circuit up to "MAX" mark.

The fluid level may drop below the "MIN" mark when the ignition is switched on.

26

Correct brake fluid level in expansion reservoir of brake circuit

 Fill brake circuit to between the "MAX" and "MIN" marks depending on the condition of the brake disks and linings.

27

Screw on cap

Number

Designation

Model 220
except
model 08/18/074/174/
179,
model 220
without special protection

Model 220
with special protection,
Model 220.08/18/074/
174/179

BA42.10-P-1002-10G

Bleed screw to brake caliper

Nm

7

14

Number

Designation

Model
220
without
special protection,
except
model
074/174

Model
220 with
special protection,
Model
220.074/174

BA42.10-P-1002-12G

Bleed screw to brake caliper

Nm

7

14

Number

Designation

Model
220
with code
Z07

BA42.50-P-1001-01B

Bleed screw on brake booster hydraulic unit

Nm

12