every time you apply the the brakes unless you turn engine off not while driving just build up pressure at the master cylinder then the brakes are fine any where from 2 days to 2 weeks and then the problem shows up again,I took it to the dealer and the tech said that was nothing wrong with the brakes and that they were working normal the master brake cyclinder has never worked quite right since the right front caliper seized up and both front calipers were replace and the brake system was flushed dodge dealers use what they call acceptable brake fluid but looks like recycled fluid as opposed to the clear dot 3 and manufacture says if dot3 brake fluid is not available to use dot4 but I still have the pedal drop when brakes are applied.