If there are no obvious leaks, stomp on the pedal real hard to try to reset the shuttle valve in the distrib block. However, the fact that it came on WHILE driving rather than right after you bled the system is more an indication of a leak rather than a shuttle valve that got off center due to the bleeding process. But never know til you look! If it is on and you have a leak - you still have either front or rear brakes (assuming they aren't ALL leaking
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