111
Turbo-compressor
Inlet manifold
with intercooler
Air cleaner
Exhaust pressure
governor
Description
The intake system for the air is entirely separated from
the fuel system. It consists of four main parts:
–
air intake with inlet pipe
–
air cleaner
–
turbocompressor
–
inlet manifold with starting pre-heater (including
intercooler on engines with intercooler). The start-
ing pre-heater is optional, so it may not be fitted on
some engines.
Air cleaner
The air cleaner is of the dry filter type. Air flows
through it from the outside to the inside.
Tighten nut hard to ensure that
all air going into the engine
goes through the filter insert.
Filter insert
Press-drop
indicator
Air cleaner, single filter insert type
Exhaust pressure
governor
Turbo-
compressor
Air cleaner
Inlet pipe with
intercooler
To
engine
The filter insert should be replaced when the pressure-
drop indicator window shows red or if the filter has
been in use for 18 months.
For more details, look up the Service Manual “Service
and Maintenance”.
The air cleaner may have one or two filter inserts. The
inner insert in the double filter variant does not need to
be replaced as often as the outer one.
Buses fitted with double filter inserts usually also have
a cyclone filter. This is mounted next to the air cleaner
intake. It swirls the incoming air so that large dust and
dirt particles drop down. When the engine stops, these
fall down through a rubber valve in the bottom of the
cyclone filter sleeve.
The rubber valve should be squeezed now and again
just to make sure no dirt has stuck inside.
