MCi Crusader II 1989 Maintenance Manual page 118

Date
1-1-8!'!
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MC-9 MAINTENANCE MANUAL
RETRACTABLE ENTRANCE STEP (OPTIONAL)
The air operated retractable step permits easier passenger
boarding by providing an additional step below the lower coach
step. Step height is 8½" (216 mm). It is shown in figure 3-41.
The retractable step is controlled by a Step In-Out switch
located on the driver's switch panel.
OPERATION
When the step is in the retracted position (no voltage ap-
plied), air pressure is automatically applied through the four-way
valve to the "in" side of the air cylinder, thus holding the step in.
A locking air cylinder extends through
two
aligned holes in the
step assembly to lock it in place only when coach air pressure is
below approximately 75 psi (517 kPa).
The step can only be extended if all of the following condi-
tions are met
A. Coach air pressure is above 75 psi (517 kPa).
B. Park brake is in the ON position.
C. Entrance door is open.
D. Step switch is actuated in the OUT position.
Figure 3-41. Retractable Entrance Step.
This will ener9izethe four-.way valve and the step relay. The
four-way valve then applies air in order to extend the step and
exhaust air from the "in" side. The Step-Out· tell-tale light
located in the driver's instrument panel wilt illuminate.
Anytime the step switch is turned to the IN position, the park
brake is pushed into the OFF position. or the entrance door is
closed securely, power will be removed and the step will retract
Any one of these situations breaks the supply voltage to the
four-way valve. thus de-ener1;izing the relay and causing relay
contacts to fall open. Simultaneously, the shutting off of power
will automatically cause the four-way valve to reverse the air to
the step, thus pushing it "in" and exhausting the "out" position.
Because the relay contacts have fallen open, the Step Out
tell-tale light will go out
Anytime the air press1,1re drops below 60 psi (413.68 kPa), a
locking air cylinder
will
not permit operation of the step. Air
pressure this low is considered unsafe to operate the step.
NOTE: In order to retract step when lock
cylinder is engaged, the system must be
cycled.
SERVICING INDIRECT LIGHTS
·1. When servicing the indirect lights, first remove the gray
vinyl snap-in molding by inserting a flat tip screwdriver under
the lip of the molding (near molding joint).
2. Pry the molding from the housing track (see photo).
3. Remove lens to expose the bulbs for the indirect lights.
4. To replace lens, first position lens in the housing groove.
5. Then position molding in the housing track and push up
to snap lock molding.
Figure 3•42. Servicing Indirect Lights.
SERVICING IN-STATION LIGHTS
1. Remove lens by inserting a flat-tip screwdriver behind
lens at notch in end of light housing (see figure 3-43).
2. Apply downward pressure on lens until lens is disen-
gaged from housing grooves.
3. To replace• lens, first position lens in one groove in
housing assembly.
4. Then apply upward pressure along center of lens until
lens snaps into place in opposite housing groove.
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Figure
3-43.
Servicing In-Station Lights.