ARM 2D4221 - Caterpillar

It is possible for the frame of the harvester head to fall when parked in the vertical position. To avoid personal injury or death and equipment damage, fasten the safety chain to the frame and the felling link. Secure the chain in an appropriate manner.
Note: The hydraulic system has accumulators that are located in the lines. After the power has been shut off always wait at least 30 seconds before you work on the harvester head.Use hydraulic oil of high quality. The oil must meet the "DIN HLP" standard. Use "ISO VG 68" oil in the summer. Use "ISO VG 32" oil in the winter. Use "ISO VG 46" oil year-round. Avoid contamination: Fill the tank through the return filter.Only use replacement hoses that have been plugged at both ends.Check the pressure to the head at port (MP) .The pressure to the minor block is adjusted by the pressure reducer (R1) in the major block. The pressure can be read at pressure test point (M1), located on the right hand side of the minor block.Checking the Condition of the Accumulator
Personal injury can result from hydraulic oil pressure and hot oil.Hydraulic oil pressure can remain in the hydraulic system after the engine has been stopped. Serious injury can be caused if this pressure is not released before any service is done on the hydraulic system.Make sure all of the attachments have been lowered, oil is cool before removing any components or lines. Remove the oil filler cap only when the engine is stopped, and the filler cap is cool enough to touch with your bare hand.
In order to avoid high stresses in the feed roller arms and the feed roller motors, the accumulator needs to work properly.In order to check the accumulator, unscrew and remove the accumulator. Only a small amount of oil should come out of the accumulator when the accumulator is removed. Check the bladder by pressing gently with a blunt object into the accumulator.A strong resistance should be felt, when the bladder of the accumulator is pressed. The accumulator is faulty if there is no resistance. Replace the accumulator.Adjusting the Pressure Reducing Valves
Connect a pressure gauge to the test point in order to check a function of the system.
Loosen the locknut on the pressure reducing valve. Adjust the pressure with the screw. The pressure will increase when the screw is turned clockwise. The pressure will decrease when the screw is turned counterclockwise. Tighten the locknut after the adjustment.Hydraulic Pressure Setting
Illustration 3 g00766266
Location of Pressure Settings
Table 1
Function     Test Point     Reducer Valve     Reduced Pressure     Shock Valve     Shock Pressure    
Main pressure (1)     MP        
28000 kPa (4060 psi)     FC1    
30000 kPa (4350 psi)    
Forward feed (2)     MF         (1)     FC2    
32000 kPa (4640 psi)    
Reverse feed (2)     MR         (1)     FC2    
32000 kPa (4640 psi)    
Servo pressure