Accessory Air Filter; Accessory Air Filter Element; Cleaning; Air Gauges (Primary, Secondary And Accessory) - PREVOST H3-41 Maintenance Manual

The rear air system emergency fill valve will
supply air to wet air tank, primary air tank,
secondary air tank and accessories air tank for
brakes, suspension and accessories systems
while the front fill valve will supply air to
accessories only.
FIGURE 5: ACCESSORY AIR FILTER

6. ACCESSORY AIR FILTER

This filter is located inside the front electrical and
service compartment (Figure 4 and Figure 5).
Its main function consists in filtering the air
supplied to the accessory air system, when
connected to an external supply line. Ensure
filter is purged whenever supplying the system
with an external air line and at least every 12,500
miles (20 000 km).
To purge, open drain valve (Figure 5) let the
moisture come out, then close the drain valve.
SECTION 12: BRAKE AND AIR SYSTEM
6.1

ACCESSORY AIR FILTER ELEMENT

MAINTENANCE
Accessory air filter element
Replace the accessory air filter element at the
intervals specified by the Lubrication And
Servicing Schedule in Section 24: LUBRICATION
& SERVICING or whenever differential pressure
exceeds 15 psi (105 kPa) between filter inlet and
outlet ports. Check condition of all three O-rings
for damage. Replace when necessary (Figure 7).
6.2

CLEANING

Clean filter body and bowl with a warm water and
soap solution.
water.
Blow dry with compressed air making sure the
air stream is moisture free and clean.
particular attention to the internal passages.
Inspect all parts for damage and replace if
necessary.
7. AIR GAUGES (PRIMARY, SECONDARY
AND ACCESSORY)
The air pressure gauges, located on the
dashboard (see "Operator's Manual" or "Owner's
Manual"), are fed from pressure transducer
installed on the DC-4 double check valve,
located on the pneumatic accessories panel in
the front service compartment.
The latter is connected to the air lines running
from the primary and secondary air tanks, as
shown on the pneumatic system diagram
provided with the vehicle. The accessory air
gauge is connected to the front pneumatic panel
in the front compartment of the vehicle. The
vehicle should never be set in motion until the
buzzer alarm and warning lights turn off, i.e.
when air pressure registers at least 85 psi (414
kPa). Moreover, if pressure drops below 85 psi
(414 kPa), the "Low air pressure" warning lights
will turn on, and the "Low air pressure" buzzer
will sound. Stop the vehicle immediately,
determine and correct the cause(s) of pressure
loss. Check the gauges regularly with an
accurate test gauge. Replace the gauge with a
new unit if there is a difference of 4 psi (27 kPa)
or more in the reading.
PA1621 Maintenance Manual All Series | Revised June 2020
Rinse thoroughly with clean
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Pay