PREVOST X3-45 Multiplex, Руководство по обслуживанию

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Section 22: HEATING AND AIR CONDITIONING
PA1562
39
9.5 DRIVER’S HOT WATER PNEUMATIC
VALVE ASSEMBLY
9.5.1 Description
The flow of hot water to the driver’s heater core
is controlled by a pneumatic NO water valve
assembly. The valve, located at the ceiling of the
spare wheel compartment, is designed so that
the pilot solenoid valve, which is part of the
assembly, opens and closes a port which directs
air pressure to the actuator casing, thereby
opening or closing the valve.
When the vehicle is operating with no current to
the pilot solenoid valve, no air pressure is
admitted to the actuator casing, the cylinder
spring pushes up against the cylinder, thereby
keeping the water valve open.
The driver’s heater water valve requires a
minimum amount of maintenance. The valve
should be free of dirt sediment that might
interfere with its operation. No other
maintenance is needed unless a malfunction
occurs.
FIGURE 41: DRIVER'S HOT WATER PNEUMATIC VALVE
ASSEMBLY
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9.5.2 Pneumatic Water Valve Disassembly
1. Shut off air supply pressure and electrical
current to the pilot solenoid valve.
Disconnect wires.
2. The water valve need not be removed from
the line. Unscrew nipple, the actuator
casing, tube, spindle and closure member
can be removed (Fig. 42).
3. Remove the snap ring using a pair of pliers.
4. You can now access all seals for
replacement
Pneumatic water valve replacement seal
kits:
* Water Side: 871311
* Actuator Side: 871312
9.5.3 Pneumatic Water Valve Reassembly
1. Assemble the actuator casing, tube, nipple,
spindle and closure member.
2. Tighten the nipple in place in the body cavity
as per figure 42. Fasten pilot solenoid vale
to the pneumatic water valve. Reconnect air
supply pressure and electrical current to the
pilot solenoid valve.
3. Check for proper operation.
FIGURE 42: PNEUMATIC WATER VALVE
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