JLG 40H Service Manual - Manual (Page 95)

SECTION 2 - PROCEDURES
3120240 – JLG Lift –
2-75
2.28 SWING DRIVE BRAKE, AUSCO
(MACHINES BUILT PRIOR TO MAY
1992). (SEE FIGURE 2-41.)
Disassembly.
1. With shaft protruding downward, remove bolts 22
alternately and evenly to reduce spring tension.
2. Remove power plate 21 and gasket 2.
3. Bearing 18 is pressed onto shaft 7 and must be
removed before removal of rotating discs 11 and
stationary discs 12.
4. Further disassembly is not recommended unless
necessary for the replacement of specific parts.
5. If further disassembly is required, remove shaft 7
and stack sub-assembly from housing 1 by lightly
tapping or pressing on the small external spline end
of the shaft and removing the shaft, bearings and
stack from housing.
6. Remove bearing 18, stationary disc 12, rotating disc
11, springs 10 and primary disc 9.
7. Remove bearing 3 from shaft using care not to dam-
age seal 4. Remove seal 4.
8. Remove springs 6 and spring retainer 5 from hous-
ing.
9. Remove piston 13 from power plate by introducing
low pressure air (15 PSI) into hydraulic inlet. Direct
piston away from operator.
10. Remove o-rings 15,17 and back-up rings 14,16 from
piston O.D. and I.D. grooves. Back-up rings will be
damaged and should not be removed if replacement
is not planned.
11. Pressure relief valve 23 can be removed and
inspected to assure spring loaded ball moves freely
and is contamination free.
Cleaning and Inspection.
1. Clean all parts thoroughly.
2. Closely inspect all parts for excessive wear, cracks,
and chips. Replace parts as necessary.
3. Discard seals and o-rings.
4. Closely inspect bearings and bearing contact sur-
faces. Replace as necessary.
NOTE: Bearings may be reused if, after thorough inspection,
they are found to be in good condition.
Assembly.
NOTE: Lubricate all seals, o-rings, cylinder of the power
plate and piston with clean hydraulic oil prior to
assembly.
1. Assemble piston 13 into power plate 21 using a
shop press, being careful not to damage the o-rings
or back-up rings. Visually align the center of the cut-
outs in piston 13 with torque pin 8 holes in power
plate 21. Avoid pushing the piston all the way to the
bottom of the cylinder in the power plate. Try to keep
the top surface of the piston flush to 1/8"(0.32 cm)
elow the machined surface of the power plate.
2. When pressing the bearing onto the shaft, press on
the inner race of the bearing and support the shaft
properly.
3. Rotating discs must be clean and dry. Worn or
heavily scored rotating discs must be replaced.
4. Press bearings 3 into housing 1. Bearing must be
seated against shoulder in housing.
5. Using a shop press install seal 4 by pressing evenly
around O.D. of seal. Use care to avoid cocking.
6. Install shaft 7 into housing. Support the inner race of
bearing 3 when pressing shaft into bearing.
7. Install gasket 2. Align properly. After installing all the
remaining internal components of the brake, install
bearing 18. Properly support the shaft when press-
ing the bearing onto shaft.