CAB INTERIOR TEMPERATURE STEPS TO AVOID HIGH CAB TEMP

VEHICLES OPERATING UNDER CONDITIONS SUCH AS LOW ROAD SPEED/HIGH DEMAND HORSEPOWER, PTO OPERATION OR EXTENDED IDLE TIME MAY EXPERIENCE HIGHER THAN NORMAL INTERIOR CAB TEMPERATURES. WHEN VEHICLES ARE ORDERED FOR APPLICATIONS WHICH RESULT IN THESE TYPES OF OPERATING CONDITIONS, SALES PERSONNEL CAN ASSURE MAXIMUM THERMAL INSULATION BY SPECIFYING SUCH OPTIONS AS RPO BYM (QUIET CUSTOM INTERIOR PACKAGE). ANOTHER RECOMMENDED OPTION IS HEAVY DUTY COOLING WHICH WILL DECREASE ENGINE OPERATING TEMPERATURES RESULTING IN LOWER HEAT INPUT TO THE CAB INTERIOR. THE USE OF TINTED GLASS AND THE STANDARD 330 SQ. IN. REAR GLASS WILL REDUCE THE EFFECTS OF DIRECT SUNLIGHT INTO THE CAB AND CONTRIBUTE TO THE REDUCTION OF CAB INTERIOR TEMPERATURES. IN SEVERE APPLICATIONS WHERE THESE COMPONENTS WERE NOT SPECIFIED FURTHER MODIFICATION MAY BE NECESSARY. AN IMMEDIATE BENEFIT IN REDUCTION OF CAB INTERIOR TEMPERATURES CAN BE REALIZED BY INSTALLING FULL CAB FLOOR INSULATION AND A PROTECTIVE MAT. PART NUMBERS FOR THE INSULATION AND MAT ARE LISTED UNDER PARTS INFORMATION BELOW. A SMALL CIRCULATION FAN INSTALLED UNDER THE DASH AREA DIRECTED AT THE FLOOR WILL CIRCULATE STAGNANT CAB INTERIOR AIR PRODUCING FURTHER REDUCTION IN TEMPERATURE. IF THE VEHICLE IS EQUIPPED WITH AN AUTOMATIC TRANSMISSION, THE FAN CAN BE MOUNTED OFF THE SHIFT TOWER. THE HEATER UNIT SHOULD BE EVALUATED, CHECKING FOR HOT AIR LEAKAGE PAST TEMPERATURE CONTROL DOORS WHEN DOORS ARE IN THE CLOSED POSITION. IF HOT AIR FLOW IS LEAKING PAST THE DOORS, A SHUT-OFF VALVE, PREVENTING HOT WATER FLOW TO THE HEATER CORE CAN BE INSTALLED. THE SHUT-OFF VALVES CAN BE PROCURED THROUGH A LOCAL PARTS SUPPLY. PARTS INFORMATION DESCRIPTION *INSULATION QUANTITY 2 PART NUMBER 8885795 DESCRIPTION REAR FLOOR MAT QUANTITY 1 PART NUMBER 2033775 DESCRIPTION CIRCULATION FAN QUANTITY 1 PART NUMBER 2234027 THESE PARTS CAN BE PROCURED THROUGH THE WDDGM ORDERING SYSTEM. *INSULATION MUST BE TRIMMED FOR PROPER FIT.

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.