BMW X3 Service & Repair Manual: Bleeding brake system with dsc

Necessary preliminary tasks:

• Remove left sensor opening.
• Read and comply with GENERAL INFORMATION.

IMPORTANT: Under certain circumstances it is not possible after the brake system is opened to bleed the brake system fully at the rear EMF brake calipers. If there is still residual air in the rear brake calipers after normal bleeding, it will be necessary to work through an ADDITIONAL BLEEDING PROCEDURE!

When replacing or repairing, observe the filling and bleeding instructions for the following parts:

• Tandem brake master cylinder.
• Hydraulic unit.
• Components and lines which are fitted between these assemblies.

Connect bleeder unit with max. 2 bar filling pressure.

A second person is needed for this repair work.

Use only BMW-approved brake fluids.

Connect diagnosis and information system.

Select path: Service functions - Chassis/Suspension - Traction control systems - Bleeding procedure.

IMPORTANT: Check relevant equipment manufacturer's operating instructions for each device.

Charging pressure should not exceed 2 bar.

Connect bleeder unit to expansion tank and switch on.

Completely bleed the brake system.

Connect bleeder hose with collecting tray to bleeder valve on rear right brake caliper.

Open bleeder valve and purge until clear, bubble-free brake fluid emerges.

Close vent valve.

Follow same procedure on rear left, front right and front left wheel brake.

IMPORTANT: In vehicles with 6-piston fixed caliper brakes two vent valves per brake caliper are installed on the front axle! In each case start by bleeding at the outer vent valve and then bleed at the inner vent valve.

Bleed the rear axle brake circuit. Connect bleeder hose with collecting tray to bleeder valve on rear right brake caliper.

Open vent valve.

Run brake bleeding procedure using the diagnosis and information system with the vent valve open.

After completing routine, press brake pedal 5 times to floor; clear and bubble-free brake fluid must flow out.

Close vent valve.

Repeat procedure at rear left.

Bleed front-axle brake circuit.

Connect vent hose with collecting vessel to vent valve on front right brake caliper.

Open vent valve.

IMPORTANT: In vehicles with 6-piston fixed caliper brakes two vent valves per brake caliper are installed on the front axle! In each case start by bleeding at the outer vent valve and then bleed at the inner vent valve.

Run brake bleeding procedure using the diagnosis and information system with the vent valve open.

After completing routine, press brake pedal 5 times to floor, clear and bubble-free brake fluid must flow out.

Close vent valve.

Repeat procedure at front left.

Switch off bleeder unit and remove from expansion tank.

Check brake fluid level. If necessary, top up/draw off to "MAX" level.

Close expansion tank.

NOTE: Pay attention to gasket (1) in sealing cap.