A fluid system for a vehicle is provided. The fluid system is configured to couple to a chassis of the vehicle. A frame assembly of the fluid system is configured to couple with the chassis directly or with another component that is coupled, directly or indirectly, with the chassis. A cowling of the fluid system can enclose a fuel pressure vessel and an auxiliary fluid vessel. The auxiliary fluid vessel is configured to be placed in fluid communication with the component powered or operated by the fluid therein.