Reply to thread

Click here to become an Official Member of BMW Club Malaysia Download Form

Message: <blockquote data-quote="t2ribena" data-source="post: 503777" data-attributes="member: 3847">the rear brake backup circuit is a separate hydraulic line that is operated from the foot brake and it is not part (independant) of the integral brake circuit...this is on the newer Integral ABS II system...for the servo assisted system then it could be different as sufficient pressure is required before the servo system can function and the rear brake circuit being dependent on the primary integral circuit in this case it still points back to the pump/ servo system if it malfunction...this is one of the reason BMW redesign the integral system which is now on the newer bikes which has a backup system in case the integral function failed...the following is the schematic for the previous version (servo)...notice that the brake caliper circuit passes through the ABS pump/servo and this decoupling of the lever to caliper means that the system is fully dependent on the servo/ pump for its function unless there is a bypass system in the unit itself...<img src="http://i158.photobucket.com/albums/t114/t2ribena/02bmw05t.jpg" alt="" class="fr-fic fr-dii fr-draggable " style="" />below is the schematic of the newer system...notice that the foot brake circuit is connected directly to the rear caliper via a 2 to 1 brake line/valve (the other one is from the integral circuit), so in this system when you depress the foot brake, the fluid displacement directly activates the rear caliper. So when the integral brake fails, the rear brake is still functioning...unlike the earlier version...<img src="http://i158.photobucket.com/albums/t114/t2ribena/bmw-abs-system-2.jpg" alt="" class="fr-fic fr-dii fr-draggable " style="" /></blockquote>

Verification