TM 55-203
The width of this paddle must be somewhat less than
the cylinder wall. Form this portion into the cylinder
the width of the slide valve seat in the bushing. Place a
while the sleeve or rod is being gradually raised, taking
small quantity of the graphite on the chamois skin and
special care not to crimp or otherwise damage the
rub the surfaces specified until they show a dark copper
packing cup Then pull upward and outward on the
color. There must be no free graphite allowed to remain
sleeve or rod until it is in horizontal position. Push the
on the valves or seats and they must be free from any
piston to its release position and then raise the sleeve or
oil or grease before the graphite is applied.
rod to the top of the cylinder to determine whether the
(4) Oiling piston Before the cleaned piston is
expander (if used) is in its proper position, which will be
indicated by freedom of movement.
replaced in the piston bushing, press the side of the
d. Triple Valve Lubrication
packing ring opposite the scarf to the bottom of its
groove, then introduce three drops of approved triple
(1) Cleaning.
Under ordinary service
valve oil in the groove through the ring scarf opening,
conditions, the triple valve should be thoroughly cleaned
after which restore the ring to its normal position and
and lubricated every 15 months. The proper interval is
carefully rotate it in its groove to distribute the oil.
best determined for each particular case by a careful
Position the ring scarf approximately 1 inch either side
inspection and trial. Where conditions are severe and
of the piston top center Next, place three drops of the
the triple valve exposed to extremes of weather, dirt,
triple valve oil in the clean, dry bushing and distribute it
etc, more frequent inspections will, no doubt, be found
over the entire surface in a manner to avoid introducing
necessary. Where the valve is protected and not
dirt or other grit. Then insert the piston and slide valve
subjected to hard usage,-the interval may be
in the body, leaving them in release position, after which
lengthened. The piston, slide valve, graduating valve,
place three additional drops of tripe valve oil in the
and bushings must be thoroughly cleaned so as to
cylinder bushing and again distribute it on the bushing
remove all dirt, oil, gum, or grease. Benzine, gasoline,
surface as previously described. No lubricant should be
or other approved cleaning fluid can be used for this
used on the quick action parts.
purpose. The piston packing ring and its groove should
be cleaned without removing the ring from the piston
8-25. General Information for Carmen and Trainmen
groove. This can be done by dipping the piston in the
cleaning fluid and then moving the ring around in the
groove. This operation should be repeated until the
a. Releasing Brakes. In releasing an individual
groove and ring are thoroughly cleaned, after which the
brake by means of the release valve on the auxiliary
excess cleaning fluid can be blown away or dried by
reservoir, the brake pipe being charged, the release
using an air jet.
valve should be held open only until the exhaust is
(2) Loosening rings. Where rings are stuck
heard to start. In this way, if the auxiliary reservoir
with dirt too tightly to be moved in the groove, it may be
pressure is reduced much below that ,in the brake pipe,
necessary to soak the ring in penetrating oil and then
the piston will go to retarded release position and the
tap the ring gently with a hard block. For this purpose, a
release will be slower. Where there is no air in the
maple or hickory wooden block about 1 by 1 by 4 inches
brake pipe, the brake must be released by holding the
(with square ends) should be used to tap the ring so as
release valve open until all the air has escaped. When
to drive it flush with the top edge of the groove. This
it is found necessary to cut out the brake, close the
tapping should start at one side of the ring joint and
cutout cock in the brake pipe branch pipe and bleed the
progress around the piston in short steps until the ring is
auxiliary reservoir.
loosened sufficiently to be moved in the groove. If this
procedure will not loosen the ring, it is evident that the
b. Road Troubles
groove is binding, in which case, the groove must be -
coniditioned and a new ring fitted.
(1) Common defects.
The most serious
(3) Glazing valves.
The face of the
defects that might cause trouble on the road are leaky
graduating valve, the upper surface of the slide valve
slide valve, leaky check valve case gasket, leaky triple
(which is the graduating valve seat), the slide valve
valve body gasket, leaky emergency
face, the slide valve seat, and the upper portion of the
bushing (slide valve spring bearing) must be glazed with
the best grade of very fine, pure, dry airbrake graphite.
To apply the graphite, it will be found convenient to use
a small wooden paddle about 8 inches long having a
small piece of chamois skin glued to the paddle end.
8-55
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