Piper PA-24 Comanche Service Manual page 642

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PIPER COMANCHE SERVICE MANUAL
TABLE IX-VII. TROUBLESHOOTING
(cont)
Trouble
Couse Remeely
Motor fails to operate.
(cont)
A new brush should
be
run in until at least SO
percent seated
i
however,
if facilities are not avail-
able for running in brushes,
then the brush should be
properly seated by insert-
ing a strip of number 0000
sandpaper between the
brush and commutator,
with the sanded side next
to the brush. Pull sand-
paper in the direction of
rotation, being careful to
keep it in the same contou
as the commutator.
CAUTION
Do not use coarse
sandpaper or emery
cloth. After seating,
clean thoroughly to
remove all sand and
metal particles to
prevent excess! ve
wear. Keep motor
bearing free from
sand or metal par-
ticles.
Dirty commutator.
If commutator is rough or
dirty. smooth and polish
with number 0000 sand-
paper, If too rough and
pitted, remove and turn
down: Blowout all par-
ticles.
Shorted, grounded, or Remove and replace with an
open armature.
armature known to
be
in
lood
condition.
ELECTRICAL SYSTEM
ISSUED: 8/18/72
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