JLG G6-42P Service Manual - Manual (Page 330)

38
Section 4
Assembly and Installation
6. Apply high torque liquid adhesive, Loctite 271 or
Three Bond 1305, to capscrew threads. Install
return springs and return spring capscrews.
Tighten to 80-115 lb-in (9.0-13.0 N•m).
Figure 4.49.
Hydraulic Apply Brake
Housing Functional Test
NOTE
• This test procedure is only for the hydraulic
apply brake system.
• To perform this test, it is necessary to use a
device which permits the observation of
possible leaks through oil seals and if the
piston return system is working. For an
accurate evaluation, the device must allow
piston displacement of 0.157 to 0.197 inch
(4-5 mm).
1. Connect brake housing assembly into hydraulic
system equipped with 1000 psi (69 bar)
manometer.
2. Activate the cylinder at least five times with 600
psi (41.4 bar). Check for leaks.
• If there are no leaks, proceed to Step 3.
• If there are leaks, disassemble brake housing
assembly, find and correct the problem.
3. Wait five minutes, then apply 600 psi (41.4 bar) to
the cylinder again.
Figure 4.49
Assemble Hydraulic Apply
Brake Housing Assembly
NOTE
• To assemble three function brake, see
page 39.
• To assemble ball and ramp brake, see page 43.
1. Check to see if the piston lodging surfaces on
brake housing is free of sharp edges, nicks and
burrs. Repair any damage if possible or replace
the part.
2. Repeat Step 1 on outer surfaces of brake piston.
3. Apply a thin film of oil, SAE W140 or SAE 90, to
piston and bore. Apply a dense layer of oil to
brake housing chamfer.
4. Carefully install piston oil seals.
NOTE
Before pressing piston into brake housing, rotate
piston 15 to 20 degrees. If piston does not turn
easily, disassemble the piston and find the cause
of the interference.
5. With a manual press, carefully install piston into
brake housing. Do not damage oil seals. If there
is resistance in installing the piston, do not
proceed. Figure 4.48.
Figure 4.48
BRAKE
HOUSING
RETURN
SPRING
SPRING
CAPSCREW
BRAKE
PISTON
OIL
SEAL
T