Usage:
CONFIDENTIAL TIBU4363-00
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TECHNICAL INFORMATION BULLETIN |
OCTOBER 6, 2004 |
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EXCAVATORS |
320C (DBG343-Up, EGA302-Up, EGL317-Up, GLA796-Up, JTG468-Up)
322C (EMR341-Up, MAR284-Up)
325C (CRB717-Up, CSJ877-Up, DTF280-Up, JLD313-Up) EXCAVATORS
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Component Code(s) 5067, 5117, 5147, 5811 |
SUBJECT: 320C, 322C, AND 325C EXCAVATORS ARE EXPERIENCING BOOM LOWERING CONTROL VALVE OPERATIONAL PROBLEMS
PROBLEM:
Reports indicate that the boom lowering check valves in the Smart Boom Circuit are not functioning properly resulting in the following conditions:
· Boom down hesitation
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Slow boom operation
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No boom down modulation
SOLUTION:
Replace the original 8J-6815 Orifice Plugs that are located inside the 233-0759 Boom Lowering Control Valves with new orifice plugs. Use the information that follows in order to replace the original orifice plugs. Illustrations 1 and 2 show the locations of the components. Table 1 lists the new orifice plug to be installed.
Illustration 1. Location of the Boom Lowering Control Valves on the Boom Cylinders
(A) 233-0759 Boom Lowering Control Valves
Illustration 2. Top view of the Boom Lowering Control Valve
(A) 233-0759 Boom Lowering Control Valve
(B) 183-7263 Plug Assembly
(C) 8J-6815 Orifice Plug
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Required Parts |
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Part Number |
Description |
Quantity |
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Orifice Plug |
2 |
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Table 1.
1. Remove 183-7263 Plug Assembly (B) from 233-0759 Boom Lowering
Control Valve (A).
2. Remove the original 8J-6815 Orifice Plug (C). Clean the thread body thoroughly.
3. Install the new 114-8229 Orifice Plug. Tighten the orifice plug to a torque of 10 ± 1 N× m (89 ± 9 lb in).
4. Reinstall the 183-7263 Plug Assembly (B). Tighten the plug to a torque of 16 ± 1.5 N× m (12 ± 1.1 lb ft).
5. Repeat Steps 1 through 4 for the other Boom Lowering Control Valve.
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ALL RIGHTS RESERVED