Installation And Alignment Of Brush Block Assembly; Replacement Of De-Ice Boots - Cessna T182 Series Service Manual

MODEL 182 & T182 SERIES SERVICE MANUAL
d. If slip ring run-out is within limits specified in be slow enough to allow the solvent to undercut the
step "c". no corrective action is required. A small cement so that parts will not be damaged. To in-
amount of run-out may be corrected by varying the stall a propeller anti-ice boot. proceed as follows:
torque of the attachment bolts within the limits speci- a.
Clean the metal to be bonded with Methyl Ethyl
fied by the propeller manufacturer. Ketone, (MEK). For final cleaning, wipe the sol-
vent film off quickly with a clean, dry cloth before
14-62. INSTALLATION AND ALIGNMENT OF BRUSH
it has time to dry.
BLOCK ASSEMBLY.
(See figures 14-8 and 14-9.) b. Prepare a pattern the size of the boot, including
three inches of the boot strap. Draw a centerline
NOTE
(lengthwise) through the pattern.
c. Draw a line on the centerline of the leading edge
Installation of the brush block should be
of the blade. Position the pattern centerline over the
deferred, when possible, until after the leading edge centerline. Position pattern so bottom
slip ring, propeller, and related compo- of boot is 1/2"below spinner cutout.
Draw a line on
nents are installed. However, the brush the propeller hub on each side of the pattern boot
block assembly may be replaced without strap where it crosses the hub.
Check boot strap
removing the propeller. To avoid break-
position by fitting restraining strap on the hub and
age when installing the brush block as-
comparing its position with the marked position of
sembly, keep brushes retracted in brush
the strap.
block until slip ring and propeller assem-
d. Mask off an area 1/2" from each side and outer
blies have been installed.
end of the pattern, and remove the pattern.
Make sure that slip ring run-out has been
Apply cement at room temperature (65°-75°F).
corrected before attempting to align
For best results, allow to air dry for a mini-
brushes on slip ring. mum of one hour at 50°F or above when rela-
tive humidity is less than 75%. If the humidity
a. In order to get smooth, efficient and quiet trans- is 75% and 90%, allow additional drying time.
fer of electric power from the brushes to the slip ring,
Do not apply cement if relative humidity is
brush alignment must be checked and adjusted, if
higher than 90% or if the temperature is below
necessary to meet the following requirements.
50°F. Allow 12 hours cement curing time
1. Projection must be such that the distance before starting engine. Allow 24 hours cement
between the brush block and the slip ring is 0. 062
curing time before operating the de-icers.
(±0. 030-inch).
2. The brushes must be lined up with the slip e. Mix EC-1300L cement (Minnesota Mining & Mfg.
ring so that the entire face of each brush is in con-
Co.) thoroughly.
Surfaces shall be 65°F prior to
tact with the slip ring throughout the full 360° of slip
applying cement. During periods of high humidity,
ring rotation.
care shall be taken to prevent moisture condensation
3. The brushes must contact the slip ring at an
due to the cooling effect of the evaporating solvent.
angle of approximately 2° from perpendicular to the
This can be done by warming the area with a heat gun
slip ring surface, measured toward the direction of
or heat lamp. Apply one even brush coat of EC-1300L
rotation of the slip ring. cement to the cleaned metal surface.
Allow to air
b. Brush projection can normally be adjusted by dry for a minimum of one hour and then apply a sec-
loosening hardware attaching the brush block and
ond even brush coat of EC-1300L cement.
holding the brushes in the desired location while
f. Moisten a cloth with Methyl Ethyl Ketone and
retightening the hardware. Slotted holes are pro-
clean the unglazed back surface of the boot, changing
vided.
cloths frequently to avoid contamination of the cleaned
c. One method for face alignment is described in
area.
step "b". Another is to use shims between brush
g. Apply one even coat of EC-1300L cement to back
block and bracket Laminated metal shims are gen-
surface of boot. It is not necessary to cement more
erally provided. Layers of metal .003" are used to than 1/2" of the boot strap.
make up shims which are approximately 0. 20" thick h. Using a silver-colored pencil, mark a centerline
overall. Shims may be fabricated locally. along the leading edge of the propeller blade and a
d. Loosen mounting bolts and twist block while corresponding centerline on the cemented side of the
tightening to attain proper angular adjustment.
boot.
i. Reactivate the surface of the cement using a
Avoid excessive rubbing of cement, which would re-
Use care not to disturb other adjustments move the cement.
when adjusting angular alignment. j. Position the boot centerline on the propeller
leading edge, starting at the hub end of the position
14-63. REPLACEMENT OF DE-ICE BOOTS.
To marked. Make sure that boot strap will fall in the
remove or loosen installed de-ice boots, use toluol position marked. Tack the boot centerline to the
to soften the "cement line".
Apply a minimum leading edge of the propeller blade. If the boot is
amount of this solvent to the cement line as tension allowed to get off-center, pull up with a quick motion
is applied to peel back the boot.
Removal should and replace properly.
Roll firmly along centerline
14-24