350 DIESEL CYLINDER HEAD GASKET LEAK PROCEDURE

350 DIESEL CYLINDER HEAD GASKET LEAK REPAIR PROCEDURES 1980-81 WHEN CYLINDER HEAD GASKET REPLACEMENTS ARE BEING MADE FOR ANY REASON ON 1980 AND 1981 MODEL DIESEL ENGINES, IT IS IMPORTANT THAT THE MOST CURRENT PROCEDURES AND THE LATEST DESIGN PARTS BE USED TO CORRECT THE CONDITION. THIS BULLETIN COMBINES THE LATEST DIAGNOSIS, REPAIR AND PARTS INFORMATION FOR USE IN MAKING A HEAD GASKET LEAK DIAGNOSIS OR REPLACEMENT ON THE 350 DIESEL ENGINE.

OVERHEATING OR NO HEAT

AN OVERHEATING OR NO HEAT FROM THE HEATER CONDITION MAY BE CAUSED BY A COMPRESSION LEAK IN THE HEAD GASKET. THIS WILL BE EVIDENT BY AIR BUBBLES IN THE COOLANT RECOVERY TANK. TO DETERMINE WHICH HEAD GASKET IS LEAKING, LOWER THE COOLANT LEVEL AND REMOVE THE THERMOSTAT HOUSING AND THE BELTS ON THE WATER PUMP. START THE ENGINE AND OBSERVE THE COOLANT IN THE INTAKE MANIFOLD TO DETERMINE WHICH SIDE THE BUBBLES ARE COMING FROM.

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.