JLG 1200SJP Service Maintenance Manual page 340

SECTION 5 - HYDRAULICS
10. Thread piston onto rod until it abuts the spacer end and
install the tapered bushing.
NOTE: When installing the tapered bushing, piston and mating
end of rod must be free of oil.
WHEN REBUILDING THE TELESCOPE, LIFT, JIB, LEVEL, AXLE LOCKOUT OR AXLE
EXTENSION CYLINDERS, TIGHTEN SECURELY. (SEE TABLE 5-1)
11. Assemble the tapered bushing loosely into the piston
and insert JLG capscrews (not vendor capscrews)
through the drilled holes in the bushing and into the
tapped holes in the piston.
Figure 5-19. Tapered Bushing Installation
12. Tighten the capscrews evenly and progressively in rota-
tion to the specified torque value. (See Table 5-1, Cylin-
der Head and Tapered Bushing Torque Specifications).
13. After the screws have been torqued, tap the tapered
bushing with a hammer (16 to 24 oz.) and brass shaft
(approximately 3/4" in diameter) as follows;
a. Place the shaft against the cylinder rod and in con-
tact with the bushing in the spaces between the
capscrews.
5-16
b. Tap each space once; this means the tapered bush-
ing is tapped 3 times as there are 3 spaces between
the capscrews.
Figure 5-20. Seating the Tapered Bearing
14. Retorque the capscrews evenly and progressively in
rotation to the specified torque value. (See Table 5-1,
Cylinder Head and Tapered Bushing Torque Specifica-
tions).
15. Remove the cylinder rod from the holding fixture.
16. Place new guide locks and seals in the applicable out-
side diameter grooves of the cylinder piston. (See Figure
5-18., Piston Seal Kit Installation)
17. Position the cylinder barrel in a suitable holding fixture.
EXTREME CARE SHOULD BE TAKEN WHEN INSTALLING THE CYLINDER ROD,
HEAD, AND PISTON. AVOID PULLING THE ROD OFF-CENTER, WHICH COULD
CAUSE DAMAGE TO THE PISTON AND CYLINDER BARREL SURFACES.
18. With barrel clamped securely, and while adequately sup-
porting the rod, insert the piston end into the barrel cyl-
inder. Ensure that the piston loading o-ring and seal ring
are not damaged or dislodged.
19. Continue pushing the rod into the barrel until the cylin-
der head gland can be inserted into the barrel cylinder.
– JLG Lift – 3121142