JLG 24RS Service Manual - Manual (Page 68)

SECTION 3 - CHASSIS & TURNTABLE
3-30 – JLG Lift – 3121287
Brake Chart, check to see if it has the proper number of springs
using the Spring Checking Procedure. Increase to maximum
pressure (refer to Table 3-3, Swing Brake Chart) and hold at
that pressure for one minute. If the brake does not leak or lose
pressure, the unit has passed the brake test. If the brake loses
pressure, attempt to repair the leak using the leak repair pro-
cedure at end of this procedure.
While the brake is still released, roll check the unit for one rev-
olution of the output member by rotating the tool. Bleed off
pressure slowly while rotating the Roll Test Tool.
Record the pressure at which the brake locks up. Using a clean
rag, wipe off excess fluid from around the brake port and
install the pipe plug.
SPRING CHECKING PROCEDURE
Install two Flat Socket Head Cap Screws 0.250-20 UNC, ½"
length into holes in the brake piston. Tighten the bolts evenly
to ensure that the brake piston remains straight while being
compressed into the brake cavity of the brake housing.
Carefully remove the retaining ring from the brake housing.
Slowly remove the bolts evenly from the input brake. Remove
the pressure plate from the end of the input brake and count
the number of springs in the brake. If the number of springs
matches the number in Table 3-3, Swing Brake Chart, go to the
next step. If number of springs does not matches the number
in Table 3-3, Swing Brake Chart, install the correct number of
springs.
Install the Pressure Plate using two 0.250-20 UNC flat Socket
Head Cap Screws. Tighten bolts evenly to ensure that pressure
plate (8M) does not get wedged to the brake cylinder.
Install the large retaining ring into groove in housing making
sure that it is seated properly. Remove all bolts from the brake
piston and discard.
USE CAUTION WHEN REMOVING THE BOLTS AS THEY ARE SUBJECT TO
SPRING PRESSURE. MAKE SURE THE RETAINING RING IS SECURED
BEFORE REMOVING BOLTS.
Re-test the input brake. If release and/or lockup pressures still
do not match the brake chart, then contact the Oerlikon Fair-
field service department.
Table 3-3. Swing Brake Chart
Number
of
Springs
Release
Pressure
Minimum
(psi)
Release
Pressure
Maximum
(psi)
Full
Release
Pressure
(psi)
Maximum
Release
Pressure
(psi)
Brake
Torque
(in-lbs)
8 90 147 157 2000 556