GROUP 6A - DIESEL ITEMS QUICK SERV. INFO. - MISC.

(THIS BULLETIN CONTAINS SEVERAL ITEMS OF SERVICE INTEREST THAT MAY BE HELPFUL TO SERVICE TECHNICIANS. PAGE THROUGH TO DESIRED SUBJECT.

GR. 6A DIESEL OIL PUMP DRIVE

SHOULD AN OIL PUMP DRIVE SHAFT CONDITION BE ENCOUNTERED WHERE THE HEX IS ROUNDED OFF INSIDE THE VACUUM PUMP DRIVE GEAR, THE OIL PUMP DRIVE EXTENSION SHAFT, PART NUMBER 559127, AND THE VACUUM PUMP DRIVE UNIT, PART NUMBER 7832145, SHOULD BE REPLACED.

OCCASIONALLY, DIFFICULTY IN THE REMOVAL OF THE VACUUM PUMP MAY BE ENCOUNTERED AS THE OIL PUMP DRIVE SHAFT ROUNDS OUT IN THE VACUUM PUMP

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

GR. 6A DIESEL INJECTION PUMP SPECIAL TOOLS

THE LIFE OF THE BRISTOL TOOL FOR REMOVING CAM PINS FROM THE INJECTION PUMP CAN BE EXTENDED BY GRINDING A 60 DEG. CHAMFER ON THE END OF THE TOOL.

THIS DRIVE SHAFT SEAL INSTALLATION TOOL SHOULD BE POLISHED THE LENGTH OF THE TOOL TO REMOVE ANY ROUGHNESS. THIS WILL IMPROVE THE INSTALLATION OF THE SEALS. 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 SHAFT IN A ROTARY MOTION WHILE PULLING ON IT. IT WILL THEN COME OUT EASIER.

GR. 6A DIESEL INJECTION NOZZLE BODY LEAKS

NOZZLE BODY LEAKS MAY BE CORRECTED BY LOOSENING THE INLET FITTING AND RETORQUING. (DED 45 FT. LBS. -- CAV 19 FT. LBS.) IN THE EVENT THIS DOES NOT CORRECT THE LEAK, POLISHING THE INLET FITTING MAY CORRECT THE LEAK. REMOVE THE INLET FITTING, LAY A PIECE OF 600 GRIT SAND PAPER OR CROCUS 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 REASSEMBLE.

GR. 6A 1980-1981 DIESEL INJECTION LINE

1981 MODEL DIESEL INJECTION LINES WILL NOT FIT THE 1980 DIESEL. ALTHOUGH THE LINE FITTINGS INTERCHANGE, THEIR CONFIGURATION AND VOLUME DIFFER AS WITH THE FASTENING LOCATION ON THE VALVE COVER.

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.