Moin dear MTler, I have a Sprinter 903 with which the brake pedal is very soft, so also very low braking performance. I have aired the system several times, also with the Star diagnosis. It is good every time for 1-2 days afterwards and then the brake pedal becomes soft again. Brake lines and hoses etc. everything is tight, there is no brake fluid missing. I exclude vacuum system because the pedal would otherwise be hard or then it wouldn’t be better after the airing. Has anyone had this before? The HBZ is already new. I suspect a defect in the ABS control block. Would I be happy about some answers. MfG