User's Manual

VM-1 Control Valve Manifold
B-W Pc. No. 283039
Ford Part No. DOHA 1B200-C
3. The VM-1 Control Valve manifold is located on the engine side of the firewall and is
bolted to an air manifold which extends through the firewall. Sealing of the ports
between the VM-1 manifold and the air manifold is accomplished by o-rings.
The manifold houses three valves that serve the trailer braking system. The valves are:
A. The SS-1 Valve (Service Line Shut-Off) which operates in conjunction with the
dash mounted PP-3 Tractor Protection Control Valve to manually or
automatically close and retain sufficient air pressure in the tractor to apply
service brakes.
B. A Double Check Valve which permits either primary or secondary circuit air
pressure from the Dual Brake Valve to normally actuate trailer service brakes.
C. A Double Check Valve which permits use of the TC-2 Trailer Control Valve to
control only trailer brakes.
In addition to ports necessary for the function of the above described valves, the VM-1
Manifold also provides ports for installation of the Service Stop Light Switch, front axle
Limiting Control Valve and TE-1 Trailer Emergency Stop Light Switch.