1978 MOTOR COACH MC5B Recall

Campaign:: 77V186000 on 10/11/1979
Component:: Service brakes, air:supply
Affected:: 1,182
Defect:: The involved vehicles do not conform to federal motor vehicle safety standard no. 121, "air brake systems". the two "o" rings that are supplied along with the new shuttle valves are of a buna "v" quality. these rings are fully functional in normal climate conditions, however, in extremely cold environments, slight leaks may develop. this valve acts as a seal between the cylinder heads of the shuttle valve and the piston. in time this seal may expand or "pucker up", making it possible for the shuttle to become trapped in an emergency braking situation.
Correction:: The dealer will replace all defective "o" rings with ones having extreme cold resistance properties.
Notes:: Vehicle description: motor homes equipped with new shuttle valves.system: service brakes; air control valve.consequences of defect: in this event, the brakes once "on" will not releaseand loss of vehicle control and an accident could result.note: driver should be alerted to this condition by a flashing light, buzzer,and a low reading on the air gauge.