Valve unit for modulating the pressure in pneumatic brake system

The invention relates to a valve unit (1, 1') for modulating the pressure in a pneumatic brake system, said valve unit comprising a brake pressure inlet (3), a brake pressure outlet (4), a bleed outlet (5), at least one pneumatically controllable main valve (6, 7), and a pilot valve (8, 9) designed as a solenoid valve and associated with the main valve (6, 7), all of said parts of the valve unit being arranged in a valve housing (2', 2') which is sub-divided, by means of a joint face (10) running largely horizontally in the assembled position, into a main housing (11, 11') and a housing cover (12). In order to be able to secure the housing cover (12) to the main housing (11, 11') in a compact and inexpensive manner, a clip element (62.1) is provided which is secured to the main housing (11, 11') in the assembled state, and a largely flat pressure plate (63) of said clip element (62.1) rests against a flat outer wall (64) of the housing cover (12) such that an elastic pre-loading force is generated, the flat o