JLG 40H Service Manual User Manual
Page 101
SECTION 2 - PROCEDURES
3120240
– JLG Lift –
2-81
2.31 SWING BRAKE, MICO. (MACHINES
BUILT FROM MAY 1992 TO S/N 33476)
(SEE FIGURE 2-45.)
Disassembly.
1.
Remove end cover 2 from housing 21 by removing
capscrews 1.
END COVER IS UNDER SPRING TENSION OF APPROXIMATELY
2000 POUNDS (907 KG). THE FOUR CAPSCREWS SHOULD BE
LOOSENED EVENLY TO RELIEVE THIS FORCE. IF A HYDRAULIC
PRESS IS AVAILABLE (3000 LBS (1362 KG) MAXIMUM), THE
COVER CAN BE HELD IN POSITION WHILE REMOVING THE CAP-
SCREWS.
2.
Remove case seal 4 from housing 21 then remove
bleeder screw 3 from end cover 2.
3.
Remove piston 7 from end cover 2.
4.
Remove o-ring 5, back-up ring 6, o-ring 8 and back-
up ring 9 from piston 7.
5.
Remove separators 13 from housing 21.
6.
Remove stack assembly, consisting of shaft 11,
return plate 14, and friction discs 12, from housing
21.
7.
Remove dowel pins 20, springs 15,16 and spring
retainer 17 from housing 21.
8.
Remove retaining ring 18 from housing 21.
9.
Remove shaft by pressing or using a soft mallet on
male end of shaft 10.
10.
Remove retaining ring 22 and bearing 19 from shaft
10.
11.
Press rotary oil seal 23 from housing 21.
Inspection.
Clean all parts thoroughly.
1.
Closely inspect all parts for excessive wear, cracks
and chips. Replace parts as necessary.
2.
Discard seals and o-rings.
3.
Closely inspect bearings and bearing contact sur-
faces. Replace as necessary.
NOTE: Bearings may be re-used if, after thorough inspec-
tion, they are found to be in good condition.
Assembly.
NOTE: Lubricate all seals and o-rings with clean hydraulic
oil prior to assembly.
1.
Clean all parts thoroughly before assembly.
2.
Press new rotary oil seal 23 into housing 21. Note
direction of seal.
3.
Install new bearing 19 and retaining ring 22 on shaft
10.
4.
Insert shaft assembly and retaining ring 18 in hous-
ing 21.
5.
Insert dowel pins 20, spring retainer 17 and springs
15,16 in housing 21.
6.
Position new large diameter return plate 14 in hous-
ing with tab guided by dowel pins 20 until disc rests
on springs 15,16.
DISC 15,19 AND FRICTION DISCS 17 SHOULD REMAIN DRY DUR-
ING INSTALLATION. NO OIL RESIDUE SHOULD BE ALLOWED TO
CONTAMINATE DISC SURFACES. PLACE A NEW FRICTION DISC
12 ON SHAFT 10 UNTIL IT CONTACTS RETURN PLATE 14.
7.
Place a new friction disc 12 on shaft 10 until it con-
tacts return plate 14.
8.
Add additional new discs 11 and new friction discs
12 as required to complete assembly.
9.
Insert separators 13 in holes of return plate 14.
10.
Install new o-ring 5, new back-up ring 6, new o-ring
8 and new back-up ring 9 on piston 7. Note order of
o-rings and back-up rings. Insert piston 7 into end
cover 2 being careful not to shear o-rings or back-up
rings.
11.
Install new case seal 4 in housing 21 then install
bleeder screw 3 in end cover 2.
12.
Position end cover 2 on housing 21 aligning dowel
pins 20 with holes in end cover.
13.
Install capscrews 1 and tighten evenly to draw end
cover 2 to housing 21. Torque capscrews to 55 ft.
lbs. (75 NM).
NOTE: If available a hydraulic press will simplify installation
of end cover on housing. Clamp cover in position
while tightening the capscrews.
14.
If hydrostatic bench testing is performed on the
brake assembly, release pressure should not
exceed 2000 psi (137 Bar) unless two additional
bolts are used for supplemental clamping.