Firenza L4-121 2.0L (1983)
Technical Service Bulletin # 83C6
Date: 831001
Campaign - Brake Proportioner Valve Separated From M/C
SUBJECT
BRAKE PROPORTIONER VALVE MAY
NUMBER: 83-C-6
SEPARATE FROM MASTER CYLINDER
DATE:
Oct.. 17, 1983
MODELS/YEARS
1983 CUTLASS CIERAS, OMEGAS
SECTION: 5
AND FIRENZAS
CONDITION
General Motors has determined that a defect which relates to motor vehicle safety exists on some 1983 Cutlass Ciera, Omega and Firenza cars. The
brake proportioner valves used on some of these vehicles may break and separate from the master cylinder. This would result in a brake fluid leak and a
partial loss of the brake system. These vehicles are equipped with a dual braking system; part of the system will still work and allow the vehicle to be
stopped, but over a greater distance. Partial loss of the brake system at a time when minimum stopping distance is required could result in a vehicle crash
without prior warning.
Vehicles, Dealer & Service Information
VEHICLES INVOLVED
Involved are certain 1983 Cutlass Cieras, Omegas and Firenzas within the following serial numbers.
SERIES
ASSEMBLY PLANT
BEGINNING
UP TO & INCLUDING
Cutlass Ciera
Doraville
DD334506
DD373389
DD376496
DD377072
DD377632
DD378204
DD384484
DD385283
Omega
Willow Run
DW311071
DW324706
DW324963
DW326249
DW327012
DW327771
DW328852
DW329505
DW331770
DW332404
DW332842
DW333260
Firenza
Leeds
DK305993
DK315268
DK318264
DK319592
DEALER ACTION
To prevent the possibility of this condition occurring on vehicles involved, dealers are to inspect to determine if a vehicle has suspect proportioner valves
as instructed in the Service Procedure of this bulletin. ALL suspect valves are to be replaced.
Dealers are to service all vehicles subject to this campaign at no charge to owners, regardless of mileage, age of vehicle, or ownership, from this time
forward.
Whenever a vehicle subject to this campaign is taken into your new or used vehicle inventory, or it is in your dealership for service in the future, you
should take the steps necessary to be sure the campaign correction has been made before reselling or releasing the vehicle.
Owners of vehicles recently sold from your new vehicle inventory are to be contacted by the dealer, and arrangements made to make the required
modification according to instructions contained in this bulletin.
SERVICE PROCEDURE
PART I Inspection of Proportioner Valves
1.
Open vehicle hood and cover left-front fender.
2.
It may be necessary to clean the ends of the front and rear brake proportioner valves located in the master cylinder for inspection. If this is
required, wipe valves clean using brake fluid. Do not use a solvent to clean the valves. as it could enter the small notches (vents) of valves
and cause damage to the internal seals of the valves.
