SMU - SECTION 6B - COOLING AND RADIATOR - DIESEL ENGINE. Chevrolet Tahoe

SUBJECT: SERVICE MANUAL UPDATE - SECTION 6B - COOLING AND RADIATOR - DIESEL ENGINE THERMOSTAT

MODELS: 1996 CHEVROLET AND GMC TRUCK C/K MODELS

THIS BULLETIN UPDATES THE THERMOSTAT REPLACEMENT PROCEDURE IN SECTION 6B, COOLING AND RADIATOR, OF THE 1996 C/K SERVICE MANUAL. DURING THE MODEL YEAR THE 6.5L DIESEL ENGINE FEATURED EITHER A SINGLE OR DUAL THERMOSTAT SYSTEM. THIS PROCEDURE ADDRESSES BOTH THE SINGLE AND DUAL THERMOSTAT SYSTEMS.

THERMOSTAT REPLACEMENT DIESEL ENGINES

REMOVE OR DISCONNECT (FIGURE 1)

1. DRAIN THE COOLING SYSTEM UNTIL THE RADIATOR COOLANT LEVEL IS BELOW THE THERMOSTAT(S). 2. UPPER RADIATOR (INLET) HOSE. 3. BOLT, STUD, AND THE COOLANT OUTLET. 4. GASKET IF SINGLE THERMOSTAT. SEALS ON THERMOSTATS IF DUAL THERMOSTAT STYLE. 5. THERMOSTAT(S) FROM HOUSING.

CLEAN * THERMOSTAT HOUSING AND COOLANT OUTLET SEALING SURFACES.

INSTALL OR CONNECT (FIGURE 1)

1. THERMOSTAT(S) INTO HOUSING.

IMPORTANT: * THE SINGLE THERMOSTAT DESIGN UTILIZES A BLOCKING THERMOSTAT AND WILL HAVE A SPRING ON THE THERMOSTAT. THE DUAL THERMOSTAT DESIGN UTILIZES A NON-BLOCKING THERMOSTAT AND WILL NOT HAVE A SPRING ON THE THERMOSTAT.

* WITH THE DUAL THERMOSTAT DESIGN, THE SEALS MUST BE INSTALLED ON THE THERMOSTATS BEFORE THEY ARE INSTALLED. THE SEALS HAVE A SPLIT INNER EDGE AND GO OVER THE FLANGE ON THE THERMOSTATS. THE SIDE OF THE SEAL WITH THE SMALL BEAD SHOULD BE INSTALLED TOWARD THE THERMOSTAT HOUSING.

2. GASKET IF SINGLE THERMOSTAT. 3. COOLANT OUTLET. 4. BOLT AND STUD.

TIGHTEN * BOLT AND STUD TO 42 N.M (31 LB FT).

5. UPPER RADIATOR (INLET) HOSE. 6. FILL THE COOLING SYSTEM. 7. START THE ENGINE AND RUN IT WITH THE RADIATOR CAP REMOVED, UNTIL THE UPPER RADIATOR HOSE BECOMES HOT (THERMOSTAT IS OPEN). 8. WITH THE ENGINE IDLING, ADD COOLANT TO THE RADIATOR UNTIL THE COOLANT LEVEL REACHES THE BOTTOM OF THE FILLER NECK. 9. RADIATOR CAP TO THE RADIATOR, MAKING SURE THE ARROWS LINE UP WITH THE OVERFLOW TUBE. 10. CHECK FOR LEAKS.

FIGURES: 1 ATTACHMENTS: 0

Object Number: 82694 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.