WATER LEAK HEATER CASE TO COWL INSTALL DEFLECTOR

SOME EARLY 1981 C-K TRUCKS MAY EXHIBIT A WATER LEAK AT THE ATTACHMENT OF THE HEATER CASE TO THE INSIDE OF THE COWL PANEL. THIS COULD OCCUR WHEN WATER RUNS INTO THE RIGHT HAND HOOD HINGE HOLE ON THE TOP SURFACE OF COWL, AND IS DRAWN INTO THE HEATER CASE BY THE BLOWER FAN. IT THEN PASSES INTO THE HEATER DISTRIBUTOR ASSEMBLY AND COULD LEAK INTO THE CAB AT MOUNTING POINTS ON THE COWL OR FROM THE DISTRIBUTOR DUCT. THIS CONDITION WAS CORRECTED IN PRODUCTION APPROXIMATELY 9/8/80 BY THE ADDITION OF A DEFECTOR TO THE RIGHT HAND HOOD HINGE HOLE TO DIVERT WATER AWAY FROM THE HEATER BLOWER INTAKE AREA. VEHICLES AFFECTED BY THIS WATER LEAK CAN BE CORRECTED BY INSTALLING P/N 14039898 DEFLECTOR AS FOLLOWS: 1.RAISE HOOD. REMOVE ATTACHING SCREWS ALONG FRONT EDGE OF COWL VENT PANEL. SPACE PANEL UPWARD WITH A PIECE OF WOOD TO PROVIDE ACCESS TO INSTALLATION AREA. REMOVE AND DISCARD RECTANGULAR SECTION OF FOAM RUBBER WHICH IS CEMENTED TO TOP SURFACE OF W/S FRAME PANEL (COWL) ADJACENT TO RIGHT HAND HOOD HINGE HOLE. 2.INSERT WATER DEFLECTOR INTO RIGHT HAND HOOD HINGE HOLE WITH CURVED EDGE FORWARD, (SEE ILLUSTRATION) POINTS C & D FLUSH WITH FRONT FACE OF COWL PANEL, AND POINTS D & A PARALLEL AND FLUSH WITH HOOD HINGE HOLE. POSITION DEFLECTOR POINT E OUTBOARD OF VENT BEZEL BY INSERTING A 12" SCREW DRIVER DOWN THE HINGE HOLE AND PUSHING END OF DEFLECTOR OUTBOARD TOWARD FENDER. IF DEFLECTOR END IS ALLOWED TO ROLL UP ON VENT BEZEL WATER COULD BE DIRECTED NEAR VENT DOOR RESULTING IN A LEAK WHEN DOOR IS OPEN. 3.APPLY TWO ROWS OF STRIP CAULK, 3M P/N 8578 OR EQUIVALENT, TO BOTTOM PERIPHERY OF DEFLECTOR FROM A TO D. SLIDE DEFLECTOR BETWEEN TOP OF COWL AND VENT PANEL AS SHOWN AND PRESS DOWN OVER CAULK AREA TO PROVIDE GOOD SEAL BETWEEN DEFLECTOR AND COWL. DRIVE A HOLE IN TOP OF COWL AT POINT C (EXISTING HOLE IN DEFLECTOR) USING AN AWL AND INSTALL HEX HEAD TAPPING SCREW, P/N 11504446. HOLE AT POINT B IS NOT USED. 4.APPLY A STRIP OF CAULK FROM POINT B TO POINT C TO SEAL EDGE OF DEFLECTOR TO COWL PANEL. 5.REINSTALL VENT PANEL SCREWS. * ILLUSTRATION *

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.