look for the washer that have sealing rings on them .some times the face is not square with the threaded part of the banjo the rings will crush this will help any off set .some times the washer is to damn hard and if flat with no sealing rings it will leak. if it is a reman caliper the sealing part can have a bad surface make sure your sealing washers are not to big and hanging out of the machine surfaces . and you are not cupping the washer