TM 5-5420-209-34
3-7. Boom Cylinder Assembly.
This task covers:
a. Test
b. Repair
INITIAL SETUP
Tools
Equipment Condition:
General Mechanic’s Tool Kit
Boom cylinder assembly removed
(NSN 5180-00-177-7033)
(TM 5-5420-209-12).
Materials/Parts
Solvent, Dry Cleaning (Item 2, Appendix B)
Rags, Wiping (Item 5, Appendix B)
Oil; Lubricating (Item 4, Appendix B)
a. Test.
WARNING
Dry cleaning solvent, PD-680, used to dean parts is potentially dangerous to personnel and
property. Avoid repeated and prolonged skin contact. Do not use near open flame or exces-
sive heat. Flash point of solvent is 100°F-138°F (38°C-60°C).
(1) Using suitable mounting and hydraulic test equipment secure cylinder with double acting hy-
draulic ports in upward position.
(2) Connect hydraulic pressure source to cylinder head port, next to the cylinder mounting fork, and
return line to cylinder port rod end.
When disconnecting any hydraulic line, open line slowly and protect face, as hydraulic oil
may spray out due to residual pressure in system.
(3) Operate hydraulic test system Continuously for at least ten minutes by repeating the following:
(a) Apply hydraulic pressure to cylinder head port and activate boom cylinder piston rod to the fully
extended position.
(b) Bleed air from rod end of cylinders necessary while piston rod is extending.
(c) Apply hydraulic pressure to cylinder rod port and activate piston rod to fully retracted position.
(d) Bleed air from cylinder head end of cylinder as necessary while the piston rod is retracting.
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