Usage:
CONFIDENTIAL TIBU4215-01
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TECHNICAL INFORMATION BULLETIN |
May 26, 2004 |
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EXCAVATORS |
345B (BFG 1-404) 345B Series II MH (APB 1-259, DET 1-109, CDY 1-312) 345B Series II (ALB 1-353, CCC 1-875, CDJ 1-201, AGS 1-1870, DCW 1-314) EXCAVATORS |
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Component Code(s) 5051 |
SUBJECT: IMPROVED CLEARANCE FOR MAIN CONTROL VALVE STEMS ON CERTAIN
EXCAVATORS
PROBLEM:
When the joystick is returned to NEUTRAL position, the machine may continue to move. These powered movements occur only at the start of the machine when the valve is cold. These powered movements happen when the oil is warmed up using only a few functions, (using only the tracks for example) before using another function (swing for example).
This may be due to a tight clearance between the stem and the body of the main valve.
The tolerance between the valve body and the valve stem has been increased. The increased tolerance prevents the stems from sticking in the body of the valve, which prevents powered movements on the machine.
The following machines will be corrected at the factory.
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Effectivity of New Tolerance on Machines |
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Model |
Effectivity |
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AGS ALB APB CCC CDJ DCW DET 2SW 7KS BFG CDY |
1871-Up 354-Up 260-Up 876-Up 202-Up 315-Up 110-Up 1-Up 1-Up 405-Up 313-Up |
SOLUTION:
If stems are sticking in the body of the valve, please contact your product support group to investigate the possibility to change the involved stems of the valve.
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Tolerance Between Stem and Body |
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Part Name |
Former Tolerance |
New Tolerance |
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Left Travel Stem Right Travel Stem Boom 1 Stem Boom 2 Stem Stick 2 Stem |
0.014 to 0.020 mm |
0.016 to 0.020 mm |
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Swing Stem Stick 1 Stem Bucket Stem Attachment |
0.012 to 0.018 mm |
0.014 to 0.018 mm |
Note: The tolerance between the stem and body for the Straight Travel Stem did not change. The tolerance remains 0.021 to 0.027 mm.
COPYRIGHT 2004 CATERPILLAR
ALL RIGHTS RESERVED