SUBSECTION 8D
BOOM HOIST BRAKES
Figure 8D-2. Boom Hoist Planetary Brake
(2100N458)
When the linings are new and the brake is in proper adjust-
ment, the length of the cylinder piston extension, with the
brake set (hydraulic pressure applied), should be 1/2 inch.
When the brake lining starts to wear, this dimension will in-
crease (with the brake set). See the Operator's Manual for
the method of adjusting the brakes for normal lining wear.
Figure 8D-2. Boom Hoist Planetary Brake (2100N458)
The boom hoist planetary should be relined when brake lin-
ing thickness reaches 3/16 inch as measured at the dead
end of the band.
3. With the engine shut down, operate a control lever until
all hydraulic pressure is exhausted from the system.
REMOVAL. To remove the boom hoist brake band, proceed
as follows (see Figure 8D-5):
4. Disconnect and cap the hydraulic lines from the boom
hoist brake and the boom hoist planetary brake cylinders.
1 . Lower the boom and support it on blocking. Make sure all
Plug all connections where hydraulic lines were removed.
tension is removed from the boom hoist rope.
5. Remove the upper deck panel immediately to the right of
2. Shut down the engine and move the boom hoist lever
the access door. This will make access to the boom hoist
forward to release the boom hoist brake. With the brake re-
brakes easier. If necessary, remove the sheet metal shroud
leased, slide pin (71) through the slot in bracket (65) and on
between the boom hoist drum and the main hoist drum.
through the drilled hole in bracket (70) as shown in Figure
8D-3. This will lock the brake in the released position.
6. Release the tension in springs (17) by loosening jam nuts
(20). Remove springs (17) from pin (21). Remove pin (21)
NOTE
from the band lever.
If adequate pressure is not available to release the
7. Remove brake band adjusting bolts (10 and 77) and
brake, the engine will have to be started to build sys-
springs (09 and 76) by removing nuts (07 and 74).
tem pressure.
8. Disengage boom hoist pawls (53 and 56) from the
Also, the assembly pin (71) may be made from 3/8
ratchets as follows:
inch steel rod stock cut to a length of 6 inches.
8D-2
