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REPAIR<br />
BACKHOES<br />
LOAD CHECK VALVES INSPECTION<br />
Procedure:<br />
Valve Plug<br />
ANTI-CAVITATION VALVE<br />
INSPECTION<br />
Procedure:<br />
Poppet<br />
Spring<br />
O-Ring<br />
Poppet<br />
Spring<br />
Plug<br />
NOTE:<br />
All six valve sections are equipped with load<br />
check valves.<br />
1. Check poppets, springs and seats for damage.<br />
Replace assembly as necessary.<br />
2. Use seal kit to replace O-rings and back-up rings.<br />
3. Tighten to 27 N•m (20 lb-ft).<br />
DIPPERSTICK CIRCUIT RELIEF<br />
VALVE INSPECTION<br />
M77721<br />
1. Be sure ball is free in retainer.<br />
2. Reinstall assembly with all new O-rings and backup<br />
rings from seal kit.<br />
BOOM CIRCUIT RELIEF VALVE<br />
INSPECTION<br />
Procedure:<br />
Ball Retainer<br />
Ball<br />
O-Ring<br />
M77719<br />
Spring<br />
Shim<br />
Plug<br />
Poppet<br />
Spring<br />
Cartridge<br />
Plug<br />
Poppet<br />
Spring<br />
Cartridge<br />
O-Ring<br />
Poppet<br />
M77720<br />
O-Ring<br />
Poppet<br />
1. Check parts for damage and contaminants.<br />
Replace complete assembly, if necessary.<br />
2. If not replaced, assemble with all new O-rings and<br />
back-up rings.<br />
3. Tighten cartridge to 27 N•m (20 lb-ft).<br />
4. Tighten plug to 19 N•m (168 lb-in.).<br />
NOTE:<br />
Install the same number and size shims that<br />
were removed. DO NOT change relief valve<br />
setting.<br />
1. Check parts for damage and contaminants.<br />
Replace complete assembly if necessary.<br />
2. If not replaced, assemble with new O-rings and<br />
back-up rings.<br />
3. Tighten cartridge to 27 N•m (20 lb-ft).<br />
4. Tighten plug to 19 N•m (168 lb-in.).<br />
NOTE:<br />
Spring<br />
M77718<br />
Install the same number of shims that were<br />
removed. DO NOT change relief valve setting.<br />
3-18 6/22/99
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