MISCELLANEOUS DIESEL INFO. MULTIPLE SUBJECTS

THIS BULLETIN CONTAINS MULTIPLE SUBJECTS. PAGE THROUGH TO DESIRED SUBJECT.

DIESEL - BASIC SERVICE ENGINE

FUTURE 1980 MODEL DIESEL BASIC SERVICE ENGINES WILL HAVE 1981 FEATURES IN- CORPORATED; THESE FEATURES ARE 1981 CRANKSHAFTS, ROD BEARINGS AND MAIN BEARING CAP BOLTS. 1981 SERVICE PROCEDURES MUST BE OBSERVED WHEN SERVICING THESE COMPONENTS. THESE ENGINES CAN BE IDENTIFIED BY NOTING THE DISPLACEMENT CASTING CODE ON THE SIDE OF THE BLOCK. ALL DIESEL ENGINE BLOCKS WITH 1981 FEATURES WILL BE MARKED 350DX.

DIESEL INJECTION PUMP SPECIAL TOOLS

THE LIFE OF THE BRISTOL TOOL, ROOSA MASTER NUMBER 15499, FOR REMOVING CAM PIN FROM THE INJECTION PUMP CAN BE EXTENDED BY GRINDING A 60 DEG. CHAMFER ON THE END OF THE TOOL.

THE DRIVE SHAFT SEAL INSTALLATION TOOL, ROOSA MASTER NUMBER 22727, SHOULD BE POLISHED THE LENGTH OF THE TOOL TO REMOVE ANY ROUGHNESS WHICH WILL IM- PROVE THE INSTALLATION OF THE SEALS.

INJECTION PUMP DRIVE SHAFT REMOVAL

THE 1981 INJECTION PUMP DRIVE SHAFT IS HELD IN PLACE WITH AN "O" RING ON THE SHAFT. IT IS DIFFICULT TO REMOVE IF PULLED STRAIGHT OUT. DO NOT TURN THE SHAFT, BUT MOVE THE END OF THE SHAFT IN A ROTARY MOTION WHILE PULLING ON IT.

DIESEL INJECTION NOZZLE BODY LEAKS

NOZZLE BODY LEAKS MAY BE CORRECTED BY LOOSENING THE INLET FITTING AND RE- TORQUING. (DED 45 FT. LBS. - CAV 19 FT. LBS.) IN THE EVENT THIS DOES NOT CORRECT THE LEAK, POLISHING THE INLET FITTING MAY CORRRECT THE LEAK. REMOVE THE INLET FITTING, LAY A PIECE OF 600 GRIT SAND PAPER OR CORCUS CLOTH ON A HARD FLAT SURFACE. PRESS AND ROTATE THE END OF THE INLET FITTING AGAINST THE PAPER, ROTATE BACK AND FORTH ABOUT 6 TIMES. FLUSH WITH DIESEL FUEL AND RE- ASSEMBLE.

DIESEL OIL PUMP DRIVE

WHEN AN OIL PUMP DRIVE SHAFT CONDITION IS ENCOUNTERED WHERE THE HEX IS ROUND- ED OFF INSIDE THE VACUUM PUMP DRIVE GEAR, THE OIL PUMP DRIVE EXTENSION SHAFT, PART NUMBER 7832145, SHOULD BE REPLACED.

OCCASIONALLY DIFFICULTY IN THE REMOVAL OF THE VACUUM PUMP IS ENCOUNTERED AS THE OIL PUMP DRIVE SHAFT ROUNDS OUT IN THE VACUUM PUMP. TO EASE REMOVAL WHEN THIS IS ENCOUNTERED, ROTATE THE ENGINE BACKWARDS APPROXIMATELY 1/4 TURN AND THEN REMOVE VACUUM PUMP.

IF THE OIL PUMP DRIVE SHAFT AND GEAR ASSEMBLY ARE TO BE REPLACED, USE PART NUMBER 22511730 FOR ALL DIESEL MODELS.

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.