John Deere — PTO driveline is stopped before making adjustments,

A John Deere service procedure — check it applies to your exact model before use.

Procedure

4.5 L and 6.8 L Level 14 Electronic Fuel System 022808 PN=13 Safety 01 000 8 DX,RCAP –19–04JUN90–1/1 Service Cooling System Safely TS281 –UN–23AUG88 Explosive release of fluids from pressurized cooling system can cause serious burns. Shut off engine. Only remove filler cap when cool enough to touch with bare hands. Slowly loosen cap to first stop to relieve pressure before removing completely. DX,READ –19–03MAR93–1/1 Follow Safety Instructions TS201 –UN–23AUG88 Carefully read all safety messages in this manual and on your machine safety signs. Keep safety signs in good condition. Replace missing or damaged safety signs. Be sure new equipment components and repair parts include the current safety signs. Replacement safety signs are available from your John Deere dealer. Learn how to operate the machine and how to use controls properly. Do not let anyone operate without instruction. Keep your machine in proper working condition. Unauthorized modifications to the machine may impair the function and/or safety and affect machine life. If you do not understand any part of this manual and need assistance, contact your John Deere dealer. CTM320 (22FEB08) 01-000-8
4.5 L and 6.8 L Level 14 Electronic Fuel System 022808 PN=14 Safety 01 000 9 DX,REPAIR –19–17FEB99–1/1 Use Proper Tools TS779 –UN–08NOV89 Use tools appropriate to the work. Makeshift tools and procedures can create safety hazards. Use power tools only to loosen threaded parts and fasteners. For loosening and tightening hardware, use the correct size tools. DO NOT use U.S. measurement tools on metric fasteners. Avoid bodily injury caused by slipping wrenches. Use only service parts meeting John Deere specifications. DX,SAFE,TOOLS –19–10OCT97–1/1 Construct Dealer-Made Tools Safely LX1016749 –UN–01JUL97 Faulty or broken tools can result in serious injury. When constructing tools, use proper, quality materials, and good workmanship. Do not weld tools unless you have the proper equipment and experience to perform the job. CTM320 (22FEB08) 01-000-9
4.5 L and 6.8 L Level 14 Electronic Fuel System 022808 PN=15 Safety 01 000 10 DX,SERV –19–17FEB99–1/1 Practice Safe Maintenance TS218 –UN–23AUG88 Understand service procedure before doing work. Keep area clean and dry. Never lubricate, service, or adjust machine while it is moving. Keep hands, feet , and clothing from power-driven parts. Disengage all power and operate controls to relieve pressure. Lower equipment to the ground. Stop the engine. Remove the key. Allow machine to cool. Securely support any machine elements that must be raised for service work. Keep all parts in good condition and properly installed. Fix damage immediately. Replace worn or broken parts. Remove any buildup of grease, oil, or debris. On self-propelled equipment, disconnect battery ground cable (-) before making adjustments on electrical systems or welding on machine. On towed implements, disconnect wiring harnesses from tractor before servicing electrical system components or welding on machine. DX,SIGNAL –19–03MAR93–1/1 Understand Signal Words TS187 –19–30SEP88 A signal word—DANGER, WARNING, or CAUTION—is used with the safety-alert symbol. DANGER identifies the most serious hazards. DANGER or WARNING safety signs are located near specific hazards. General precautions are listed on CAUTION safety signs. CAUTION also calls attention to safety messages in this manual. CTM320 (22FEB08) 01-000-10
4.5 L and 6.8 L Level 14 Electronic Fuel System 022808 PN=16 Safety 01 000 11 DX,SIGNS1 –19–04JUN90–1/1 Replace Safety Signs TS201 –UN–23AUG88 Replace missing or damaged safety signs. See the machine operator’s manual for correct safety sign placement. DX,SPARKS –19–03MAR93–1/1 Prevent Battery Explosions TS204 –UN–23AUG88 Keep sparks, lighted matches, and open flame away from the top of battery. Battery gas can explode. Never check battery charge by placing a metal object across the posts. Use a volt-meter or hydrometer. Do not charge a frozen battery; it may explode. Warm battery to 16°C (60°F). DX,SPRAY –19–16APR92–1/1 Protect Against High Pressure Spray TS1343 –UN–18MAR92 Spray from high pressure nozzles can penetrate the skin and cause serious injury. Keep spray from contacting hands or body. If an accident occurs, see a doctor immediately. Any high pressure spray injected into the skin must be surgically removed within a few hours or gangrene may result. Doctors unfamiliar with this type of injury should reference a knowledgeable medical source. Such information is available from Deere & Company Medical Department in Moline, Illinois, U.S.A. CTM320 (22FEB08) 01-000-11
4.5 L and 6.8 L Level 14 Electronic Fuel System 022808 PN=17 Safety 01 000 12 DX,TORCH –19–10DEC04–1/1 Avoid Heating Near Pressurized Fluid Lines TS953 –UN–15MAY90 Flammable spray can be generated by heating near pressurized fluid lines, resulting in severe burns to yourself and bystanders. Do not heat by welding, soldering, or using a torch near pressurized fluid lines or other flam mable materials. Pressurized lines can accidentally burst when heat goes beyond the immediate flame area. DX,WEAR –19–10SEP90–1/1 Wear Protective Clothing TS206 –UN–23AUG88 Wear close fitting clothing and safety equipment appropriate to the job. Prolonged exposure to loud noise can cause impairment or loss of hearing.

Source: manual:ctm320.pdf. Figures and steps are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.