Brake Clutch Service - BRADEN PD12C Series Installation Maintenance And Service Manual

BRAKE CLUTCH SERVICE

DISASSEMBLY
1. Remove the snap ring and sprag bushing retainer
from one end only.
NOTE: The brake clutch on PD17A hoists use a
stepped inner race, which eliminates one retaining ring
and bushing retainer. The larger end of the inner race
is toward the motor.
2. Pull the inner race out. Examine the race for scor-
ing, wear or indentations caused by the sprag cams.
3. Use a screwdriver and mallet to remove the sprag
bushing from one end of the outer race. There are
four special cut-outs in the bushing for this purpose.
Be careful not to damage the bushing inside sur-
face. If a bushing's inside surface is damaged or
shows wear, replace it.
4. Next, slide the sprag clutch out, inspect the sprag
clutch closely for abnormal wear, cracks, pitting or
corrosion. Check small clips for breakage or bright
spots; the signs of excessive wear. Unless the out-
er race or remaining sprag bushing is damaged or
shows excessive wear, there is no need for further
disassembly. If disassembly is necessary, remove
the bushing according to the procedure covered in
Step No. three (3). All brake clutch assembly parts
should be thoroughly cleaned and inspected before
assembly.
The polished surfaces of the races and sprag cams
must be perfectly smooth to insure positive engage-
ment of the clutch. The slightest defect may reduce
brake clutch effectiveness, which may lead to loss of
load control and result in property damage, personal
injury or death. It is generally recommended to re-
place the entire brake clutch assembly if any compo-
nent is defective.
ASSEMBLY
1. Press a sprag bushing into the outer race, using a
mechanical or hydraulic press. A fl at plate of ap-
proximately the same diameter as the bushing
fl ange outside diameter should be placed between
the press and bushing during assembly to pro-
tect the bushing. Be certain the bushing fl ange is
against the shoulder in the outer race.
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