A brake valve system for a pair of railroad freight cars (40) mechanically connected together in a substantially semi-permanent manner. Each of such pair of freight cars has a brake pipe (14) pneumatically connected together. The brake valve system comprises a brake control valve (12) disposed on a first one of such pair of cars and is pneumatically connected to the brake pipe and to a reservoir (16) disposed on the first one of the pair for applying and releasing brakes disposed on both of the pair of freight cars. A vent valve (36) is disposed on a second one of the freight cars and is pneumatically connected to the brake pipe disposed on the second one of the pair of cars for emergency venting of air from the brake pipes of the pair of cars for emergency application of the brakes of the pair of cars.