Service Manual

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ELECTRICAL SYSTEM 7-23
Brush Spring Inspection
l inspection the brush springs for pitting, cracks, rusting and burrs.
Replace the spring if necessary.
l inspect the springs for weakened conditions and distortion. Replace
the springs if necessary.
*If the brush springs are able to press the brushes firmly into place, they
may be considered serviceable. If they cannot, replace them.
Armature Inspection
0 Inspect the surface of the commutator.
*If it is scratched or dirty, polish it with a piece of very fine emery cloth,
and clean out the grooves.
l Measure the depth of the grooves between the commutator segments.
*If the grooves are shallower than the specified limit, undercut the
insulating material to the standard depth 0.5 to 0.8 mm (0.012 to
0.031 in) using a thin file.
*If the grooves are only dirty, clean them carefully.
Commutator Groove Depth Limit
Less than 0.2 mm (0.008 in)
1. Bad 4. 0.2 mm (0.008 in) limit
-2. Segment
5. Mica
3. Good
OMeasure the commutator outside diameter at several points.
*If the diameter is less than the service limit, replace the armature with
a new one.
Commutator Outside Diameter
Service Limit: 27 mm (1.06 in)
@Support the armature in an alignment jig at each end of the shaft as
shown. Position a dial indicator perpendicular to the commutator.
0 Rotate the armature slowly and read the commutator runout.
*If runout is more than the service limit, turn down the commutator or
replace the armature with a new one.
Commutator Runout
Service Limit: 0.4 mm (0.016 in)