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TM5-2420-222-34
14-11.
BACKHOE CROWD VALVE REPAIR (Con’t).
3.
Clean all other metal parts with dry cleaning solvent. Dry thoroughly with compressed air.
4.
Clean bellows with rags dampened with water and detergent solution. Rinse with clean water. Dry thoroughly with
clean, dry rags.
5.
Inspect spool spring (4) for cracks, breaks, and abnormal bends. Using spring tester and torque wrench, apply 27
lb (120 N) of force and measure compressed length of spring. Compressed length must be 1.1875 in.
6.
Inspect spring (19) for cracks, breaks, and abnormal bends. Using portable spring resiliency tester and
machinist’s rule, apply 8 oz (2.2 N) of force and measure compressed length of spring. Compressed length must
be 0.8125 in. (20.6375 mm).
NOTE
Valve body and valve are a matched set. If either part Is damaged, both must be
replaced.
7.
Inspect valve (14) for burrs and rough spots.
8.
Inspect all other metal parts for cracks, breaks, and abnormal bends. Inspect threaded parts for damaged
threads.
c.
REPAIR
1.
Remove rough spots or burrs from valve (14) using 600 grit abrasive cloth.
2.
Restore damaged threads using pipe threading or screw threading set.
d
ASSEMBLY
1.
Coat two new preformed packings (21) and new backup washers (22) with hydraulic fluid.
TA701588
14-58
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