PLUGGED CATALYTIC CONVERTER REPLACEMENT INFORMATION

PLUGGED CATALYTIC CONVERTERS MAY OCCUR ON SOME 1981 VEHICLES EQUIPPED WITH FEDERAL 3.8L, 4.4L, 5.0L AND CALIFORNIA 5.0L ENGINES BUILT BY CHEVROLET. IF POOR ENGINE PERFORMANCE OR A NO START CONDITION IS EXPERIENCED, AND THE IGNITION, FUEL AND MECHANICAL SYSTEMS ARE OPERATING PROPERLY, THE DUAL BED BEAD CATALYTIC CONVERTER SHOULD BE REPLACED WITH THE APPROPRIATE THREE (3) WAY SINGLE BED BEAD CONVERTER (SEE PARTS LIST). THE REPLACEMENT CONVERTERS WILL CONNECT TO THE EXISTING EXHAUST SYSTEMS OF THE VARIOUS VEHICLES INVOLVED WITH SOME MODIFICATIONS. THE CONVERTER AIR SUPPLY SYSTEM, FROM THE AIR MANAGEMENT VALVE TO THE CONVERTER MUST BE MODIFIED. ALSO, A SERVICE MODIFICATION LABEL (FIGURE NO. 1) IS TO BE INSTALLED ON EACH VEHICLE. CATALYTIC CONVERTER REPLACEMENT 1. RAISE VEHICLE ON HOIST. 2. DISCONNECT AIR SUPPLY PIPE FROM CATALYTIC CONVERTER. 3. DISCONNECT INTERMEDIATE EXHAUST PIPE FROM CONVERTER. 4. DISCONNECT CONVERTER HANGER AT CONVERTER. 5. REMOVE THE FRONT EXHAUST CLAMP THEN REMOVE THE CONVERTER. 6. REVERSE THE REMOVAL PROCEDURE FOR INSTALLATION OF THE NEW SINGLE BED CATALYTIC CONVERTER. REFER TO FIGURES NO. 2 AND NO. 3 FOR THE PARTS AND INSTALLATION TORQUE REQUIREMENTS. 7. LOWER VEHICLE. CONVERTER AIR SUPPLY MODIFICATION 1. DISCONNECT DIVERT HOSE FROM THE CONVERTER AIR SUPPLY PIPE CHECK VALVE. REMOVE AND DISCARD AIR SUPPLY PIPE AND CHECK VALVE. ON CABALLERO, ALSO REMOVE AND DISCARD CONVERTER AIR SUPPLY HOSE FROM THE AIR MANAGEMENT VALVE. REFER TO FIGURE NO. 4. 2. CUT THE DIVERT HOSE TO THE AIR CLEANER (THE HOSE BETWEEN THE EXISTING "Y" CONNECTOR AND THE CONNECTOR AT THE AIR CLEANER) IN LENGTHS OF 2" AND 4-3/4". INSERT AN ADDITIONAL "Y" CONNECTOR, P/N 14031110, AS SHOWN IN FIGURE NO. 5. 3. CONNECT DIVERT HOSE FROM THE AIR MANAGEMENT VALVE TO THE "Y" AS FOLLOWS; CABALLERO USE HOSE, P/N 14045881, FROM STOCK. CUT HOSE AS REQUIRED TO PROVIDE A GOOD FIT BETWEEN THE AIR MANAGEMENT VALVE AND THE "Y" CONNECTOR. 4. CLEAN AN AREA NEAR THE VEHICLE EMISSION CONTROL LABEL WITH A DEGREASING TYPE CLEANING FLUID (NOT SOAP AND WATER) AND INSTALL THE SERVICE MODIFICATION LABEL, P/N 14060697. THIS VEHICLE HAS BEEN MODIFIED PURSUANT TO INSTRUCTIONS CONTAINED IN GMC TRUCK SERVICE BULLETIN NO. 82-B-34. PART NO. 14060697 FIGURE NO. 1 A SUPPLY OF LABELS WILL BE SENT TO EACH DEALER ALONG WITH BULLETINS IF ADDITIONAL LABELS ARE REQUIRED, ORDER THEM THROUGH: GMC TRUCK & COACH DIVISION ATTN: TECH. SERVICE BULLETIN COORDINATOR 660 SOUTH BLD., EAST PONTIAC, MICHIGAN 48053 PARTS LIST DESCRIPTION PART NUMBER REQ. PER VEHICLE CATALYTIC CONVERTER 8999642 1 "Y" CONNECTOR HOSE 14031110 1 HOSE CLAMP 1470030 2 HOSE 14045881 1 EXHAUST CLAMP 2-1/4" 1259609 1 BOLT (PIPE TO REAR CONV.) 11502877 2 BOLT (HANGER TO CONV.) 11504596 2 SERVICE MODIFICATION LABEL 14060697 1 FIGURE NO. 3 THIS IS A SUPPLEMENT TO TRUCK SERVICE BULLETIN 82-B-34. IF A 1981 VEHICLE HAS FAILED A DUAL BED BEAD CATALYTIC CONVERTER FOR ANY REASON, THE DUAL BED CONVERTER MUST BE REPLACED WITH A SINGLE BED BEAD CONVERTER AS DESCRIBED IN BULLETIN 82-B-34, DATED MARCH, 1982.

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.