United States 77V119000
General Motors, LLC
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 owners should 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.
Units 1232