One embodiment of the present invention provides a system that facilitates generating random data-encryption keys for data files. The braking system includes a braking ECU on each trailer and a communication interface being provided so that the braking ECU on a first trailer and the braking ECU on a second trailer are able to communicate with one another. The core is then combined with a polymer matrix and extruded or molded to form a structure having the desired shape. There is also a method for accommodating changes in volume of hydraulic fluid within the main chamber of the hydraulic pump housing.