CONFIDENTIAL

In a stalled condition, while performing multiple functions (bucket and stick or stick and boom functions); when one of the implement control levers is returned from the stall condition and passes through into the neutral position, the control of that implement may become erratic. The intensity of the symptom varies as the stroke of the cylinder changes. The highest intensity occurs at the mid-stroke of the cylinder. Adjustment of the Gain/Response Control may not eliminate the erratic cylinder movement.

If a machine exhibits erratic implement hydraulic cylinder movement, calibrate all implement control system pressures and all valve pressure settings. Use the Vehicle Information Display System (VIDS) menu to confirm that the settings are correct. After confirmation that the pressures are set correctly, perform the following procedure:

1. Locate the three plugs identified in Illustration 1.
2. Remove the 9S-4191 Plug.
   
   Note: Work on only one hydraulic circuit at a time. Start with the bucket circuit when multiple circuits are affected.
3. Remove the 5J-5004 Orifice Plug (1) shown in Illustration 1, Section A. The plug has an orifice of 2.4 mm (0.094 in).
4. Install a new orifice that is one size smaller than the original. Continue installing a plug that is one size smaller, until the erratic movement is eliminated. Typical sizes are listed in the table.
   
   August 01, 2001
   Component Code(s) 5051
   
5. If the erratic implement hydraulic cylinder movement is eliminated in the bucket circuit and the erratic movement in the stick or boom circuit continues, repeat Step 2 through Step 4 on those hydraulic circuits respectively.

Reference: SEPD0282, Service Magazine, November 27, 1995,
Page 5, "Various Size Orifice Plugs Available Through Parts Department".

Note: Orifice sizes that are smaller than the 4J-9780 Orifice Plug 1.6 mm (0.062 in) may be tried. A smaller orifice could result in a slower implement control response time.

August 01, 2001
Component Code(s) 5051

Illustration 1. Main Control Valve
B. Stick Control Hydraulic Circuit
C. Boom Control Hydraulic Circuit
D. Bucket Control Hydraulic Circuit

August 01, 2001
Component Code(s) 5051

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