The invention relates to a valve unit for modulating the pressure in a pneumatic brake system, comprising a brake pressure inlet, a brake pressure outlet, a vent outlet, a diaphragm inlet valve, a diaphragm outlet valve, and a pilot valve for each diaphragm valve, the pilot valves being arranged in an elongate valve housing (having a main housing and a housing cover. The inlet valve pilot valve and the outlet valve pilot valve are arranged substantially centrally above the diaphragms of the inlet valve and the outlet valve in the housing cover and with the actuation axes of the pilot valves running parallel to the parting plane, and the housing cover includes a central insert which has valve bores and control channels and into which the solenoids and the mechanical components of the pilot valves are inserted, the central insert being encapsulated with a plastic material.