Diffuser Adjustment; Maintenance; Diffuser Extension - (H3-45 Vip / X3-45 Vip) - PREVOST H3-41 Maintenance Manual

FIGURE 6: DIFFUSER ASSEMBLY

5.1 DIFFUSER ADJUSTMENT

Should an adjustment of the diffuser position be
necessary, first remove
aftertreatment roof ventilation grill.
CAUTION
To prevent paint damage and fiberglass
overheating caused by hot exhaust gases, the
diffuser louvered cover must be flush with the
roof surface or may not exceed the roof
surface more than 3/32 inch (2 mm).
CAUTION
Tighten clamps properly in order to prevent
any movement of the diffuser assembly. An
impact wrench is necessary.
1. Loosen the clamp securing the diffuser
assembly to the catalytic converter.
FIGURE 7: DIFFUSER POSITION ADJUSTMENT
2. For proper angular position, make sure that
the two edges shown on figure 7 are parallel
with each other.
SECTION 04 : EXHAUST AND AFTERTREATMENT
04014
the exhaust
PA1615 Maintenance Manual All Series | Section 04 revised September 2016
3. Using a straightedge, adjust the diffuser
assembly level. The top surface of the
warning plate fixed on the diffuser louvered
cover must be flush with the roof surface or
may exceed about 3/32in (2mm).
4. Tighten the clamp securing the diffuser
assembly to the catalytic converter.
5. Reinstall the exhaust aftertreatment system
roof ventilation grill and deflector.

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 cap nuts;
3. Slide the heat shield over the extension;
"THIS DIFFUSER
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