JLG 340AJ, Service And Maintenance Manual

Page: 167 / 370

SECTION 5 - HYDRAULICS
3121259 – JLG Lift – 5-7
c. After the Rod assembly is pulled from the barrel,
unscrew the head using a spanner wrench.
d. After disassembling the rod assembly, place it on a
support.
IF THE CYLINDER IS AT A VERTICAL POSITION FOR DISASSEMBLY, GIVE ATTEN-
TION TO THE FOLLOWING; WHEN THE HEAD IS UNSCREWED AND THE ROD
ASSEMBLY IS PULLED FROM THE BARREL, THERE IS A SPACE BETWEEN THE
HEAD AND PISTON. IT IS POSSIBLE FOR THE HEAD TO SUDDENLY SLIDE
DOWN, POSSIBLY CAUSING INJURY. TO PREVENT THIS, THE HEAD SHOULD BE
PUSHED AGAINST THE PISTON BEFORE PROCEEDING.
IF A CYLINDER IS AT A HORIZONTAL POSITION FOR DISASSEMBLY, GIVE
ATTENTION TO THE FOLLOWING; IT IS POSSIBLE FOR THE ROD TO FALL AND BE
DAMAGED WHEN REMOVED FROM THE BARREL IF NOT PROPERLY SUP-
PORTED. PLACE SUPPORT UNDER THE BARREL AS SHOWN BELOW.
5. Place the Rod assembly on blocking as shown below.
Use the pin hole to keep it from rotating.
6. Unscrew the Piston Nut.
a. Unscrew the set screw. Caulking is used to lock the
setscrew so grind the caulking area and then
unscrew the set screw.
b. Remove the steel ball
c. Unscrew the piston nut. The piston nut is secured
with a torque specified in Table 5-4, Piston Nut
Torque. 1.5 x this torque is needed to remove the
nut. If the stronger torque is needed, use a power
wrench operated by a hydraulic unit
NOTE: If it is not a set screw type, continue with the disassembly of
the piston nut.
7. Remove the PISTON NUT, PISTON and GLAND in
sequence.