NHTSA Campaign Id 81V095000; Date: Aug. 10, 1981
1980 Buick Skylark; 1980 Chevrolet Citation; 1980 Oldsmobile Omega; 1980 Pontiac Phoenix
Component: Service Brakes, Hydraulic:foundation Components:differential Proportional Valve
Manufactured by: General Motors Corp.
Affected Units:: 47,371
Under certain conditions, the rear brakes could lock up without prior warning during high deceleration braking. The problem may be caused by defective proportioner valves in the braking system.
The dealer will inspect the brake system proportioner valves and if necessary install new valves.
Vehicle description: passenger vehicles with manual transmissions. System: service brakes; rear brakes. Consequences of defect: rear brake lockup could cause a loss of vehicle controland an accident.
Date Owners notified by Manufacturer: Aug 25, 1981
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