JLG 1850SJ Service Manual - Manual (Page 213)

SECTION 5 - BASIC HYDRAULIC INFORMATION & HYDRAULIC SCHEMATICS
3121619 – JLG Lift – 5-43
CLEANING AND INSPECTION
1. Clean parts thoroughly with approved cleaning solvent.
2. Inspect rod for scoring, tapering, ovality, or other dam-
age. If necessary, dress rod with Scotch Brite or equiva-
lent. Replace rod if necessary.
3. Inspect inner surface of barrel for scoring or other dam-
age. Check inside diameter for tapering or ovality.
Replace if necessary.
4. Inspect threaded portion of barrel for damage. Dress
threads as necessary.
5. Inspect piston surface for damage, scoring, or distortion.
Dress piston surface or replace piston as necessary.
6. Inspect seal and O-ring grooves in piston for burrs and
sharp edges. Dress surfaces as necessary.
7. Inspect cylinder head inside diameter for scoring or
other damage, and for ovality and tapering. Replace as
necessary.
8. Inspect threaded portion of head for damage. Dress
threads as necessary.
9. Inspect seal and O-ring grooves in head for burrs and
sharp edges. Dress applicable surfaces as necessary.
10. Inspect cylinder head outside diameter for scoring,
damage, ovality, and tapering. Replace as necessary.
11. Inspect oil ports for blockage or presence of dirt or other
foreign material. Repair as necessary.
ASSEMBLY
NOTE: Use proper cylinder seal kit for cylinder assembly. See your
JLG Parts Manual.
Apply a light film of hydraulic oil to all components before
assembly.
1. Position cylinder barrel in a suitable holding fixture.
2. Use seal tool to install new rod seal into applicable cylin-
der head gland groove.
IMPROPER SEAL INSTALLATION CAN CAUSE CYLINDER LEAKS AND IMPROPER
CYLINDER OPERATION.
3. Install O-ring (7), back-up ring (6), and O-ring (5) in appli-
cable outside diameter groove of cylinder head (8).
3. Install two wear rings (9), seal (10), and rod wiper (11) to
inside grooves of cylinder head.
4. Install seal (2) and wear ring (3) to piston end of rod (1).
INSERTING ROD OFF-CENTER CAN DAMAGE PISTON AND CYLINDER BARREL
SURFACES. USE EXTREME CARE WHEN INSTALLING C YLINDER ROD, HEAD,
AND PISTON.
NOTE: Apply anti-seize compound to cylinder head threads.
5. Insert piston end into barrel cylinder. Do not damage or
dislodge piston loading O-ring and seal ring. Push rod in
barrel as far as possible without excess force.
6. Slide cylinder head assembly (8) over rod and screw into
barrel. Tighten cylinder head with pin spanner wrench.
.
.
Figure 5-78. Cylinder Head Installation