User Manual

SECTION 2 - PROCEDURES
2-34 – JLG Lift – 3120884
2.18 DRIVE BRAKE - MICO
Disassembly
1. Remove pressure plate (3) from cover (21) by
removing cap screws (1) and wa shers (2).
PRESSURE PLATE IS UNDER SPRING TENSION OF APPROXI-
MATELY 680 KGF (1500 LBS). THE FOUR CAP SCREWS SHOULD
BE LOOSENED EVENLY TO RELIEVE T HIS FO RCE. IF A HYDRAU-
LIC PRESS IS AVAILABLE, 1361 KGF (3000 LBS) MINIMUM, THE
PRESSURE PLATE CAN BE HELD IN POSITION WHILE REMOV-
ING THE CAP SCREWS AND WASHERS
2. Remove case seal (4) from co ver (21) .
3. Remove pisto n (7) fr om pressu re pla te (3).
4. Remove o-ring (5), back-up ring (6), o-ring (8) and
bac k-up ring (9 ) from piston (7).
5. Remove stack assembly, consisting of stator disc
(11), sensor ri ng (12), ro tor disc (13), and plate (1 4)
from cover (20).
6. Remove dowel pins (20), springs (15) and spring
retainer (16) from cover (21). Note number and pat-
tern of springs.
7. Remove retaining rin g (17) from cover (21).
8. Remove shaft (10) by pressing or using a soft mallet
on male end of shaft (10).
9. Remove retaining ring (19) and bearing (18) from
shaft (10).
10. Press rotary oil seal (22) from cover (21).
Assembly.
NOTE: Lubricate all rubber components from the repair kit
with clean type fluid used in the system.
1. Clean all parts thoroughly before assembly.
2. Press new rotary seal (22) into cover (21). Note
directio n of s eal.
3. Install new bearing (18) and retaining ring (19) on
shaft (10).
4. Install shaft assembly and retaining ring (17) in
cover (21)
5. Install dowel pins (20), spring retainer (16) and
springs (15) in cover plate (21). Be sure to use the
same number of springs and spring pattern as
recorded during disassembly.
6. Position plate (14) on springs (15).
NOTE: Disc (13 &11) and plate (14) must remain dry dur-
ing installation. No oil residue must be allowed
to contaminate disc surfaces.
7. Place a new friction disc (13) on shaft (10) until it
contacts plate (14). Install stator disc (11).
8. 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. Insert piston ( 7) into pressu re plate
(3). Be careful not to shear o-rings or back-up rings.
9. Install new case seal (4) in cover (21).
10. Position pressure plate (3) on cover (21) aligning
dowel pins (20) with holes in pressure plate.
11. Install cap screws (1) and washers (2) and tighten
evenly to draw pressure plate (3) to cover (21).
Torque cap screws 74.6 N-m (55 lb.-ft.).
NOTE: A hydraulic press will simplify installation of
pressure plate on cover. Clamp pressure plate in
position while tightening the cap screws.
IF HYDROSTATIC BENCH TESTING IS PERFORMED ON THE
BRAKE ASSEMBLY, RELEASE PRESSURE SHO ULD NOT EXCEED
137.9 BAR (2000 PSI) UNLESS TWO ADDITIONAL BOLTS ARE
USED FOR SUPPLEMENTAL CLAMPING.
Bleeding
I
1. Install brake in system and connect pressure lines.
2. Bleed pressure release section of brake by pressur-
izing side inlet port and allowing air to escape from
top port. Pressure should not exceed 6.9 bar (100
lb) during bleedin g.
3. Apply suffici ent p ressure to release b rake and check
for proper operation in system.