DUST INTRUSION PAST AIR FILTER (INSTALL DUAL STUD COVER). Chevrolet Astro

SUBJECT: DUST INTRUSION PAST AIR FILTER DURING OFF-ROAD USE (INSTALL DUAL STUD AIR CLEANER COVER)

MODELS: 1986-93 CHEVROLET AND GMC S/T TRUCKS AND M/L VANS 1992 CHEVROLET AND GMC C/K AND P TRUCKS AND G VANS 1991-92 OLDSMOBILE BRAVADA WITH 4.3L TBI ENGINES (RPO LB4 - VIN Z)

************************************************************* * THIS BULLETIN CANCELS AND SUPERSEDES CORPORATE BULLETIN * * 036001R. PREVIOUS DIVISIONAL PUBLICATION NUMBERS WERE: * * CHEVROLET 91-21-6 * * GMC TRUCK 91-6-06 * * GM OF CANADA 90-643-102 * *************************************************************

CONDITION:

SOME OWNERS OPERATING THEIR VEHICLE OFF ROAD OR IN EXTREMELY DUSTY CONDITIONS MAY EXPERIENCE DUST INTRUSION PAST THE AIR CLEANER ELEMENT.

CORRECTION:

THE DUST INTRUSION MAY BE REDUCED OR ELIMINATED BY INSTALLING A DUAL STUD AIR CLEANER COVER.

SERVICE PROCEDURE:

THE FOLLOWING STEPS SHOULD BE USED TO INSTALL A DUAL STUD AIR CLEANER LID (SEE FIGURE 1):

1. REMOVE AIR CLEANER. 2. REMOVE AND DISCARD OLD AIR CLEANER STUD. 3. REMOVE ADAPTER RING FROM THROTTLE BODY. 4. REMOVE AND DISCARD TWO REAR THROTTLE BODY ATTACHING BOLTS. 5. INSTALL TWO NEW TBI HOLD DOWN BOLTS. TORQUE THE BOLTS TO 16 N.M (12 LBS. FT.). 6. INSTALL ADAPTER RING ON THROTTLE BODY. 7. INSTALL TWO NEW AIR CLEANER STUDS INTO TOP OF TBI HOLD DOWN BOLTS. TORQUE STUDS TO 5 N.M (4 LBS. FT.). 8. INSTALL LOWER AIR CLEANER BODY. 9. REINSTALL AIR FILTER ELEMENT. 10. INSTALL NEW AIR CLEANER LID USING TWO NEW WING NUTS.

SERVICE PARTS INFORMATION: FOR S/T AND C/K TRUCKS, USE THE FOLLOWING PARTS LIST:

PART NUMBER DESCRIPTION QUANTITY ----------- ----------- -------- 10105373 BOLT, TBI HOLD DOWN (REAR) 2 10118792 NUT, WING 2 25098971 LID ASSEMBLY 1 10187639 STUD, AIR CLEANER - 143 MM 2

FOR M/L AND G/P TRUCKS, USE THE FOLLOWING PARTS LIST:

PART NUMBER DESCRIPTION QUANTITY ----------- ----------- -------- 10105373 BOLT, TBI HOLD DOWN (REAR) 2 10118792 NUT, WING 2 25098971 LID ASSEMBLY 1 10187640 STUD, AIR CLEANER - 170 MM 2

PARTS ARE CURRENTLY AVAILABLE FROM GMSPO.

WARRANTY INFORMATION:

FOR VEHICLES REPAIRED UNDER WARRANTY, USE:

LABOR LABOR TIME OPERATION VEHICLE (HOURS) --------- ------- ---------- T1604 S/T 0.2 M/L 0.4 C/K 0.2 G 0.5 P 0.4

FIGURES: 1

Object Number: 84097 Size: FS

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.