If your BMW brake pedal is soft when you press it, there is a good chance that air is trapped in the brake system.
Brake fluid does not compress, while air does. Thus any air in your BMW brake lines will make your brake pedal soft and your braking less efficient.
- BMW brakes may feel soft when pressing the brake pedal
- Spongy brake pad feeling
- BMW brake pedal sinks to the floor
What you will need
When bleeding the BMW brake system, you should work with the wheel farthest from the ABS pump.
The following videos show you how to manually bleed BMW brakes using the bleed valve at each brake caliper.
- Loosen your wheel lug nuts, secure, and jack up the car. Remove the wheel.
- Locate the brake bleeder screw behind the brake caliper.
- Connect a clear hose or place a small container near the bleed screw. Brake fluid will squirt from the tips of the bleed screw.
- Have a friend press the brake pedal and keep it pressed.
- While your friend is holding down on the brake pedal, use a brake bleeder wrench or a combination wrench to loosen the bleed screw. Wait until brake fluid comes out, then tighten the screw. Tighten the bleed screw before your friend releases the brake pedal.
- Have the friend pump the brake pedal a few times, then keep the brake pedal pressed.
- Loosen the brake screw and wait a few moments for the brake fluid to come out. Tighten the bleed screw while your friend continues to hold the brake pedal down.
- Repeat this procedure for all the brake calipers.
- Check the brake fluid and add BMW Brake Fluid if the level is below the MIN mark.
Bleed BMW DSC Pump
If your BMW brakes continue to feel soft (mushy), the next step would be to bleed the ABS pump, also known as the DSC pump, in BMW terms. To do so, you will need to use a BMW scanner to activate the DSC motor and bleed the system.
These steps will vary depending on the scanner that you are using.
- Connect your scanner to the OBD-II port under the dashboard.
- Turn on the ignition.
- Select your BMW model.
- Go to Body and select Dynamic Stability Contol or (DSC)
- Call up ECU functions or Adaptations.
- Perform DSC Pump Motor activation / Brake Bleeding.
Rheingold ISTA/D + ISTA/P
- Connect ISTA/D to your BMW and load the software.
- Select Vehicle Management in the upper bar.
- Select the Service Function.
- Select Chassis and Suspension
- Traction Control
- Brake Bleeding Routine
- Press Start on the bottom right.
Once you complete the BMW brake bleeding procedure, your brakes should feel much firmer. Monitor the brake fluid level in the next few days and ensure that you are not losing any brake fluid.