Brake Bleeding: Service and Repair
Bleeding brake system with DSC
Read and comply with General Information.
Remove heater bulkhead.
Observe filling and bleeding instructions when replacing or repairing:
- Brake master cylinder
- Hydraulic unit
- Components and connecting lines which are fitted between these assemblies.
- Precharging pump
After work has been carried out on the precharging pump, only the front-axle brake circuit has to be bled. Before flushing the brake system, activate the precharging pump once with the Diagnosis and Information System (DIS) (bleeder unit connected with max. 2 bar filling pressure).
- Connect DIS.
- Call up service function "Bleeding DSC Hydraulics".
- Connect brake fluid changer to expansion tank and switch ON.
Note:
Check relevant operating instructions for each device.
Charging pressure must not exceed 2 bar.
Flushing brake system completely
Attach bleed hose with container to bleed valve on rear right brake caliper.
Open bleed valve and flush until clear, bubble-free brake fluid emerges.
Close bleeder valve.
Follow same procedure on wheel brakes rear left, front right and front left.
Bleeding rear-axle brake circuit
Attach bleed hose with container to bleed valve on rear right brake caliper.
Open bleed valve.
Allow bleeding procedure with DIS to take its course with bleed valve open.
After procedure is completed, press brake pedal down fully 5 times; clear, bubble-free brake fluid must emerge.
Close bleeder valve.
Repeat procedure at rear left.
Bleeding front-axle brake circuit
Attach bleed hose with container to bleed valve on front right brake caliper.
Open bleed valve.
Allow bleeding procedure with DIS to take its course with bleed valve open.
After procedure is completed, press brake pedal down fully 5 times; clear, bubble-free brake fluid must emerge.
Close bleeder valve.
Repeat procedure at front left.
Switch off brake fluid changer and remove from expansion tank.
Check brake fluid level.
Close expansion tank.
Note: Take care of rubber gasket (1) in lid.