24 Dealer Service
MAN0306 (Rev. 6/16/2006)
ADJUST CONTROL VALVE LINKAGE
Reconnect control linkage to valve.
Control handles should be positioned as shown.
When completing a maintenance function on the valve,
perform a functional test by placing control handles in
their various positions and make certain the correct
operation occurs corresponding to the decals on the
operator's console. Pay specific attention to the float
position of the boom. Do not operate backhoe if func-
tions differ from the decal.
If the functions differ from the decal, check to make
sure control linkage is correctly installed and check
plumbing schematics to make sure hoses are correctly
connected.
Figure 18. Control Lever Adjustment
HYDRAULIC CYLINDER REPAIR
General Hydraulic Repair Information
A clean working area is essential for any hydraulic
repair.
All parts must be carefully cleaned before reassembly.
We recommend that when repairing hydraulic compo-
nents, you always replace existing seals with new
ones. Clean all components in solvent and blow dry
with low pressure air.
Boom, Dipperstick, Bucket & Stabilizer
Cylinders
The only repair parts available for these cylinders are
seal kits. If damage occurs to one of the cylinder com-
ponents, replace the cylinder.
Figure 19. Boom, Dipper, Bucket, Stabilizer Cylinder
Disassemble
Remove retaining ring (G) from barrel (2). Slide rod
assembly (3) out of barrel. Inspect inside of cylinder
barrel and rod surface for any scratches or scouring.
Small scratches can be removed with fine crocus cloth.
If scratches cannot be repaired, replace entire cylinder.
Clamp tube end of rod assembly in vise. Use a small
torch to heat nut (4) and break down the thread-locking
compound. Remove nut. Remove piston (5) and rod
guide (1) from rod assembly. Clean threads on rod
assembly and nut. Discard all seals.
Assemble
Lubricate new seals with clean oil. Install O-ring (D)
and back up ring (E) in the outer groove of guide (1).
Note the position of the backup ring. Install rod seal (F)
in inner groove of rod guide. Note that the lips of the
seal should be toward the piston side of the guide.
Install wiper (H) with lip pointed outward from guide.
Slide rod guide onto rod assembly.
Install O-ring (B) and seal (A) on piston (5). Apply oil to
threads on rod assembly. Slide O-ring (C) over threads.
Install piston. Apply permanent type thread-locking
compound to rod threads and install nut. Torque nut to
125-135 lbs-ft.
Lubricate seals, slide rod assembly into tube and install
snap ring (G) to complete assembly.
1. Rod guide
2. Barrel
3. Rod assembly
4. Nut
5. Piston
A. Seal
B. O-ring
C. O-ring
D. O-ring
E. Backup ring
F. Rod seal
G. Retaining ring
H. Wiper
