PISTON ASSEM. 9N1549 - Caterpillar

Always perform service on the Harvester Head from the side or the rear of the work tool.Could cause serious injury or death from improperly servicing the Harvester Head.
Perform the following required steps before performing any maintenance procedure:
Secure the Harvester Head in the upright position with a chain
Lower the Harvester Head to the ground
If equipped, engage the parking brake on the host machine
Stop the engine on the host machine. Remove the engine start switch key before exiting the machine
Turn the battery disconnect switch to the OFF position
Relieve the hydraulic pressure on all functions by moving the joystick and control levers to relieve pressure
Purge all air from the reservoirRefer to the Operation and Maintenance Manual of the host machine for additional information.
Illustration 1 g02660882
(A) Upper fixed knife (B) Upper arm knife blades (C) Lower arm knife blades (D) Lower fixed knife
Inspect the upper fixed knife (A), upper arm knife blades (B), lower arm knife blades (C) and lower fixed knife (D), for nicked, gapped, or rolled edges.
If sharpening of the knife blades is required, refer to, "Delimbing Knife Cutting Edges - Sharpen".