Pneumatic Down Force

1. CAUTION: Avoid serious injury from exploding parts due to over-pressurization or operating the system without all components in place.

   • Do not inflate system above 1779 N (400 lb. down force) (827 kPa (8.2 bar) (120 psi)).
   • Do not remove pressure relief valve.
   • Do not pressurize system unless all row unit components are in place.
   
   

   IMPORTANT: Do not lower machine with zero air pressure in system. Maintain 76—120 N (17—27 lb. down force) (34 kPa to 55 kPa (0.3 bar to 0.5 bar) (5 psi to 8 psi)) in system or air springs can kink. If air spring kinks, raise machine and pressurize the system until air springs straighten out.

   IMPORTANT: Do not operate if a pinched or unrolled air spring occurs. Lower system pressure until air springs can be rolled by hand. Roll air spring back over lower piston. Incremental lowering of machine is required to start air spring rolling over lower piston.

   NOTE: It is normal for system air pressure to drop when frame is raised and increase when frame is lowered.

   NOTE: Some additional down force on row units that follow in tractor tire tracks can be required. An extra single down force spring can be installed on these row units, without affecting other row units. See your John Deere™ dealer for more information.

   
   A68216-UN-22JUL10

   Properly Rolled Air Spring

   
   A66834-UN-25MAR10

   Properly Rolled Air Spring (Twin Row Planters)

   
   A68217-UN-22JUL10

   Improperly Rolled Air Spring

   
   A66835-UN-25MAR10

   Improperly Rolled Air Spring (Twin Row Planters)

   
   A68379-UN-26JUL10

   Single Rank Valve Block

   
   A72712-UN-21SEP11

   Dual Rank Valve Block

   A - Valve Stem

   B - Handle (If Equipped)

   C - Manual Overrides

   Ensure handle (B) (if equipped) is horizontal when operating planter.

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2. A fill valve (A) has been provided to charge the air spring circuit with shop air in the event of a compressor system failure.

3. Manual overrides (C) are provided to increase or decrease air spring pressure in the event of a down force control system failure. Air spring pressure can be checked with a tire pressure gauge at fill valve (A).