THE BRAKE PEDAL LOST ALL PRESSURE AND BRAKES DID NOT FUNCTION PROPERLY IMMEDIATELY AFTER HITTING SOME SMALL BUMP IN THE ROAD. THIS CAUSED A COLLISION WITH THE CAR IN FRONT OF MY VEHICLE. EVEN AFTER VEHICLE WAS REPAIRED FOLLOWING THIS COLLISION, MASTER CYLINDER REPLACEMENT, AND FULL BRAKE SERVICE, THIS ISSUE STILL PERSISTS. SMALL ROAD BUMPS MAKE THE BRAKES MOMENTARILY NON-FUNCTIONAL.