JLG M400 Service Manual Service Manual - Manual (Page 172)

SECTION 5 - HYDRAULICS
5-18 – JLG Lift – 3121827
NOTE: When installing the tapered bushing, piston and mat-
ing end of rod must be free of oil.
WHEN REBUILDING THE STEER, LOWER LIFT, LEVEL CYLINDER,
OR UPPER LIFT CYLINDER, APPLY LOCTITE #242 TO TAPERED
BUSHING BOLTS, THEN TIGHTEN SECURELY.
11. Assemble the tapered bushing loosely into the pis-
ton and insert JLG cap screws (not vendor cap
screws) through the drilled holes in the bushing and
into the tapped holes in the piston.
12. Tighten the cap screws evenly and progressively in
rotation to the specified torque value. (See Table 5-1,
Cylinder Head and Tapered Bushing Torque Specifi-
cations.)
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
contact with the bushing in the spaces between
the cap screws.
b. Tap each space once; this means the tapered
bushing is tapped 3 times as there are 3 spaces
between the cap screws.
14. Retorque the cap screws evenly and progressively
in rotation to the specified torque value. (See Table
5-1, Cylinder Head and Tapered Bushing Torque
Specifications.)
15. Remove the cylinder rod from the holding fixture.
16. Place new guide locks and seals in the applicable
outside diameter grooves of the cylinder piston.
(See Figure 5-19., Piston Seal Kit Installation)
17. Position the cylinder barrel in a suitable holding fix-
ture.
EXTREME CARE SHOULD BE TAKEN WHEN INSTALLING THE CYL-
INDER 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
supporting the rod, insert the piston end into the
barrel cylinder. Ensure that the piston loading o-ring
and seal ring are not damaged or dislodged.
Figure 5-20. Tapered Bushing Installation
Figure 5-21. Seating the Tapered Bearing
Figure 5-22. Poly-Pak Piston Seal Installation