Wiper Seal Installation - JLG 400S Service And Maintenance Manual

SECTION 5 - BASIC HYDRAULICS INFORMATION & SCHEMATICS
2. Use a soft mallet to tap a new wiper seal into the appli-
cable cylinder head groove. Install new bearing, buffer
ring, backup ring and retaining ring into the applicable
inside diameter of the cylinder head groove.
Figure 5-64. Wiper Seal Installation
3. Place new o-rings and backup ring in the applicable out-
side diameter groove of the cylinder head.
O-RING
BACKUP RING
Figure 5-65. Installation of Head Seal Kit
4. Carefully install the cylinder head on the rod, ensuring
that the wiper seal, backup ring, retaining ring and rod
seals are not damaged or dislodged. Push the head
along the rod to the rod end, as applicable.
5. Using suitable protection, clamp the cylinder rod in a
vise or similar holding fixture as close to piston as possi-
ble.
6. Place a new o-ring in the inside diameter groove of
spacer. Install the spacer tube onto the cylinder rod.
7. Carefully thread the piston on the cylinder rod, hand
tight, ensuring that the o-ring and backup rings are not
damaged or dislodged. Secure using setscrew and ball.
Torque setscrew to 15 ft. lbs. (20 Nm).
8. Remove the cylinder rod from the holding fixture.
5-74
EXTREME CARE SHOULD BE TAKEN WHEN INSTALLING THE CYLINDER ROD,
HEAD AND PISTON. AVOID PULLING THE ROD OFF-CENTER, WHICH COULD
O-RING
CAUSE DAMAGE TO THE PISTON AND CYLINDER BARREL SURFACES.
MAF00260
9. Place new wear rings and piston seal in the outer piston
diameter groove. (A tube, with I.D. slightly larger than
the O.D. of the piston is recommended to install the
solid seal).
WEAR RING
PISTON SEAL
Figure 5-66. Piston Seal Kit Installation
10. Position the cylinder barrel in a suitable holding fixture.
11. 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 wear rings and
piston seal are not damaged or dislodged.
12. Continue pushing the rod into the barrel until the cylin-
der head can be inserted into the barrel cylinder.
13. Screw the cylinder head into the barrel using a hook
wrench and torque the cylinder head.
14. Caulk at the machined area of the cylinder barrel end so
that it locks the cylinder head in place and it does not
unscrew from the barrel.
Figure 5-67. Caulking
15. Install the new o-rings, plugs, check valve, cartridge
valves, pressure compensator valve and orifice plug in
the cylinder port block. Torque as per values shown in
Figure 5-60.
MAF00270
MAF00120
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