41
1. Place the brake housing into a supporting structure
with the large end facing up. The supporting struc-
ture can be the motor end of the cable drum, the
hoist ring gear, or other square-cut tubular structure
that will allow the housing to clear the work surface
by a minimum of 2 in. (50 mm).
2. Insert the thrust washer into the pocket in the bot-
tom of the brake housing.
3. Insert the brake shaft into the brake housing. Take
care to keep from dropping the brake shaft and
damaging the thrust washer.
4. Place the large brake plate spacer into the bottom of
the brake housing.
5. Install a metal brake plate into the brake housing
against the spacer. Alternately, install the friction
discs and brake plates into the housing. Alignment
of the slots and holes in the brake plates is not crit-
ical.
NOTE:
When installing new brake plates, soak the
friction plates in new oil prior to installation.
6. Lubricate the o-rings and back-up rings with clean
oil and install them onto the brake piston.
NOTE:
T
he concave surface of the back-up ring
must be located next to the o-ring.
Let the assembly set for 10 minutes in order to allow
the seals to return to their original shape before fur-
ther assembly.
7. Here, the o-rings and back-up rings are shown cor-
rectly installed. The back-up rings must be located
outside the o-rings.
8. Lubricate the outside of the piston with clean oil or
light grease.
9. Using 3/8-16 UNC eyebolts inserted in the lifting
holes, lower the piston into the brake housing.
Ensure the piston is located squarely in the bore,
then, carefully press the piston into the bore to the
seals.
NOTE:
To aid assembly, use two (2) ½-13 UNC
bolts with large washers inserted into housing bolt
holes located 180° apart. Using two (2) heel bars
inserted under the washers, apply even pressure to
both heel bars to press the piston into place.
10. Insert twenty-five (25) brake springs into the piston.
11. If the bearing is loose or is being replaced, press it
fully into the bore in the cover.
12. Lubricate the o-ring and install it into the groove on
the end cover and install the cover. Position the
cover such that the vent and drain ports are located
90° from the brake release port on the side of the
brake housing. Apply Loc-Tite 242 to clean, dry bolt
threads and install the bolts and washers slowly and
evenly, in a criss-cross pattern, to avoid binding in
the assembly. Torque the bolts to 110 lb-ft (150 N-
m).
13. Connect a hand pump with a 0-2000 PSI (0-13,800
kPa) pressure gauge to the brake release port fit-
ting. Apply 800 PSI (5,500 kPa) and let the assem-
bly stand for 3-5 minutes. Turn the brake shaft by
hand to ensure the brake is released. If the brake
shaft will not turn, slowly increase the pressure in
the piston until it becomes free. If the pressure
drops, the seals must be checked to ensure they
were not damaged or rolled out of position during
assembly.
The brake piston weighs approximately 78 lbs (35
kg). Use the proper precautions when handling these
parts to eliminate the possibility of component dam-
age or personal injury.
If the end cover does not mate correctly to the hous-
ing, a brake plate may be out of position and may be
damaged.
CAUTION
The brake housing weighs approximately 145 lbs (66
kg). Use the proper precautions when handling these
parts to eliminate the possibility of component dam-
age or personal injury.
Back-up Ring
Back-up Ring
O-Ring
O-Ring