GMC C30 1977: SERVICE BRAKES, HYDRAULIC:POWER ASSIST:VACUUM

General Information

NHTSA Campaign ID Number: 77V119000

Make Model Year
GMC C30 1977
Date Owners Notified Date Received by ODI Date Added to Database
1977-08-10 1977-08-10 1979-10-12

Manufacturers Involved: General Motors, LLC

Component: SERVICE BRAKES, HYDRAULIC:POWER ASSIST:VACUUM

Potential Number Of Units Affected: 1232

Report Initiator: MFR MFR Report

Summary

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.

Remedy

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.