Mack ASET AC - Oil Coalescing Air Filter Removal

Page 134
MAINTENANCE
FUEL FILTER ELEMENT
REPLACEMENT FOR ASET™
AC ENGINES
Primary/Secondary Fuel Filter
Change
[231 BA]
SPECIAL TOOL REQUIRED
앫 Fuel and Oil Filter Wrench J 24783
For engines produced before December 22,
2003, clean or replace the pre-pump filter screen
and change the secondary fuel filter at each
specified oil and filter change interval.
For current-production engines (December 22,
2003 and later production), change the
chassis-mounted primary filter and replace the
secondary filter on the supply pump at each
specified oil and filter change interval. The
pre-pump filter is no longer used and the port is
plugged on current-production engines.
ASET™ AC FILTER DESCRIPTION
The pre-pump filter on the ASET™ AC engine,
located at the bottom of the fuel supply pump,
uses a screen cartridge to remove particulates
that would damage the pump gears (Figure 116).
The cartridge is fitted into a transparent housing
that allows visual inspection for sediment in the
trap. The cartridge housing is threaded onto the
pump housing for easy removal for cleaning or
replacement of the cartridge.
The high filtration primary spin-on fuel filter
element (3–5 microns) used on CEGR engines is
also located on the supply pump (Figure 117). It
is mounted to a metric-threaded spud at the
pump’s pressure outlet. The filter element is fitted
with a fuel-drain port at the bottom.
116
Figure 116 — Pre-Pump Filter
Because of ice buildup in the fuel system or fuel
waxing which can clog fuel filters, it may be
necessary to reduce the time or mileage interval
between fuel filter changes during extremely cold
weather.
General field practice is to prime the fuel filters
before installation. This practice can allow dirt to
enter the outlet port of the filter if caution is not
used. Use filtered fuel only when priming the
filter. Prime through the series of small holes on
the top of the filter. DO NOT prime the filter
through the center hole.
1. Screen Housing
2. Screen Cartridge
3. O-Ring
5-111.bk Page 134 Monday, July 10, 2006 2:26 PM