Service Brakes, Hydraulic:power Assist:vacuum

NHTSA recall 77V119000 · announced August 10, 1977 · filed by General Motors Corp. · 1,232 units affected

The problem

ON THE INVOLVED VEHICLES, THE NUTS WHICH ATTACH THE BRAKE MASTER CYLINDER TO THE HYDRO-BOOST UNIT MAY HAVE BEEN OVER-TIGHTENED. THIS COULD HAVE CAUSED STRIPPED THREADS AND CRACKED ATTACHING FLANGES. SHOULD THESE NUTS FAIL, THE PARTS MAY SEPARATE AND LOSS OF SERVICE BRAKES WOULD RESULT.

What to do

DEALER WILL INSPECT FOR CRACKS IN THE ATTACHING FLANGES; UNITS WITH CRACKS PRESENT WILL BE REPLACED. IF NO CRACKS ARE FOUND, THE STUDS WILL BE REMOVED AND THE HOLES DRILLED OUT. THE UNIT WILL BE REASSEMBLED USING BOLTS AND NUTS IN PLACE OF THE EXISTING STUDS.

Notes

VEHICLE DESCRIPTION: LIGHT TRUCKS.SYSTEM: SERVICE BRAKES; MASTER CYLINDER TO HYDRO-BOOST UNIT ATTACHING NUTS.CONSEQUENCES OF DEFECT: LOSS OF BRAKING CAPABILITY COULD OCCUR WITHOUT PRIORWARNING AND COULD CAUSE LOSS OF VEHICLE CONTROL AND AN ACCIDENT.

Vehicles covered by this recall

• 1977 Chevrolet C30
• 1977 Gmc C30

Source: National Highway Traffic Safety Administration public recall data. This page reports official records and is not legal, medical, or repair advice.