MCi Crusader II 1989 Maintenance Manual page 153

Date
1-1-89.
Page. _. __
4_-2_3 _ _
MC-9 MAINTENANCE MANUAL
Figure 4-27. Test Fitting Remote From
Pressure Regulator Valve.
TEST EQUIPMENT REQUIRED
A
tee
litting and plug are installed in the outlet port of the
pressure regulating valve. This enables installation of a test
gauge for adjusting or checking the pressure regulating valve
setting.
The following items of equipment are required to check the
pressure regulating valve air pressures.
A. TMCIMCI Part No. 16C-2-95 • Charging Hose· {Yellow
Jack Hose) HCL-36.
B. TMCIMCI Part No. 16C-2-96 - Pressure Gauge. 0-400
lbs. with R-12 and R-22 Pressure Scales (No. 172 CA 2½").
NOTE: Any suitable gauge and hose may
be used for this procedure. The above
gauge and hose can
be found In
Air Condi•
tloning Test Kit No. 16C-2-92.
Operators who do not already have the test kit in their inven-
tory may purchase the required items. They are available from
Universal Coach Parts, Inc .• Northlake, Illinois and in Canada
.lrom Motor Coach Industries. Service Parts Division.
TEST PROCEDURE
1. Remove the dust cap lrom the test fitting. Attach pressure
gauge No. 16C-2-96 to the test point by means of the pressure
hose No. 16C-2-95. If the pressure reading is not correct. per-
lorm steps 2 and 3. If correct, disconnect test equipment (step
4l.
2. Loosen the locknut. turn the adjusting
screw
counter-
clockwise to reduce the pressure approximately 1 0 psi (69 kPa)
below the pressure required.
3. Turn the adjusting screw clockwise to increase the pres-
sure slowly until the required. pressure setting is reached.
Tighten the locknut
4. Remove the gauge and hose and replace the dust cap on
the test fitting.
CLEANING AND INS-PECTION
1. Wash all metal parts in cleaning solvent.
2. Examine the diaphragm and, if cracked worn or damaged,
replace with new diaphragm.
3. Inspect inside of valve for water or damage. If the valve is
excessively grooved, or pitted, it should be replaced.
4. Replace any other parts that appear worn or damaged.
(Screen and inlet parts should also be removed and cleaned.)
RESERVOIRS
Reservoirs store compressed air so there will be an ample
supply for immediate use. Four air reservoirs are used on the
coach; two in the service brake system. one in the park brake
system, and one in the accessory air suspension system. See
figure 4-28.
Air compressors pass a certain amount of oil in order to
lubricate the cylinder walls and piston rings. Also, depending
on the humidity, the atmosphere entering the compressor con-
tains a certain amount of water. Thus, oil and water normally
pass into the reservoir in the form of vapor because of the heat
generated during compression.
After
reaching the reservoir,
the vapor cools and condenses in the form of an oil and water
emulsion and is drained by a drain cock at the bottom of the
reservoir.
In addition to periodic draining, the reservoirs should be
checked for mounting integrity, for outer surface corrosion and
damaged lines and fittings.
Figure 4-28. Reservoirs in Front Bogie Area.
FRONT ANO TRAILING AXLE
BRAKE CHAMBERS
Brake chambers convert compressed air pressure into
mechanical force and movement which applies the vehicle
brakes. Brake chambers on the front axle and the trailing axle
are of the clamp ring type. See figure
4-29.
The diaphragm is
held between two plates by a clamping ring, two nuts and two
bolts.
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