BMW X3 Service & Repair Manual: Replacing fluid in brake system

Necessary preliminary tasks:

• Remove left sensor opening

IMPORTANT: When carrying out repairs to the brake system, follow the procedure set out in BLEEDING BRAKE SYSTEM WITH DSC.

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 BRAKE BLEEDING PROCEDURE! Use only BMW-approved brake fluids.

Connect bleeder unit to expansion tank and switch on.

NOTE: Follow the applicable equipment manufacturer's Owner's Handbook.

Charging pressure should not exceed 2 bar.

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.

Switch off bleeder unit and remove from expansion tank.

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

Close expansion tank.

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