Maintenance; Diffuser Extension - (H3-45 Vip / X3-45 Vip); Diesel Exhaust Fluid (Def) Tank And Injection System - PREVOST H3-41 Maintenance Manual

5.2 MAINTENANCE

At vehicle inspection intervals, inspect the
diffuser assembly as follows:
 Inspect diffuser grille for stress cracking;
 Check for presence of foreign matter and
debris inside the diffuser housing, remove
and clean if applicable;
 Check for proper functioning of the rain cap
inside the diffuser housing, make sure that it
moves freely;
 Make sure that the water drain tube is not
clogged. Pour a cup of water into the diffuser
housing and assure that all the water is
drained at once at the other end of the drain
tube. If tube is clogged, remove tube and
blow compressed air inside, in reverse flow;
 Check that the warning plate
SURFACE MUST BE FLUSH WITH THE ROOF
is still in place.
SURFACE"
MAINTENANCE
Diffuser assembly
Inspect the diffuser assembly at the intervals
specified by the Lubrication And Servicing
Schedule in Section 24: LUBRICATION &
SERVICING.
5.3 DIFFUSER EXTENSION –
(H3-45 VIP / X3-45 VIP)
A diffuser extension is available for converters.
To install:
1. Remove the existing diffuser louvered cover;
2. Mount the extension on the diffuser housing.
Secure with the 10 existing nuts;
3. Slide the heat shield over the extension;
4. Place the diffuser louvered cover over the
assembly and secure with a second set of 10
identical nuts.
SECTION 04 : EXHAUST AND AFTERTREATMENT
"THIS DIFFUSER
PA1621 Maintenance Manual All Series | January 2017
FIGURE 8: DIFFUSER EXTENSION
FIGURE 9: DIFFUSER EXTENSION FOR MOTORHOMES
6. DIESEL EXHAUST FLUID (DEF) TANK
AND INJECTION SYSTEM
The DEF tank and injection system control unit
continuously vary the amount of DEF injected in
response to the engine's current load conditions.
Diesel Exhaust Fluid (DEF) is stored in a 16
gallons (60 liters) plastic tank located curb side,
in the condenser compartment.
A pump located beside the DEF tank is used to
pressurize the system and deliver the fluid.
A heating coil inside the tank uses engine
coolant to keep the DEF in a liquid state or to
melt DEF at engine start up during cold season.
DEF is injected into the exhaust gases through
an injection nozzle located between the DPF
and the catalytic converter (refer to figure 1).
In the catalytic converter, nitrogen oxides are
transformed into harmless nitrogen gas and
water.
The system notifies the driver when it is time to
top up with DEF.
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