TM 5-3810-300-24&P-3
5.7
WATER FILTER AND CONDITIONER
The engine cooling system water filter and conditioner
1) is a compact by-pass type unit with a
replaceable element.
A correctly installed and properly maintained water filter
and conditioner provides a cleaner engine cooling
system, greater heat dissipation, increased engine
efficiency through improved heat conductivity, and
contributes to longer life of engine parts.
The filter provides mechanical filtration by means of a
closely packed element through which the water passes.
Any impurities such as sand and rust particles
suspended in the cooling system will be removed by the
straining action of the element. The removal of these
impurities will contribute to longer water pump life and
proper operation of the thermostat.
The filter also serves to condition the coolant by
softening the water to minimize scale deposits, maintain
an acid-free condition and act as a rust preventive.
Fig. 1 - Water Filter and Conditioner
Corrosion inhibitors are placed in the element and
dissolve into the water, forming a protective rust-proof
Make-up water up to approximately 40% of the total
film on all of the metal surfaces of the cooling system
capacity of the cooling system may safely be added
(refer to Section 13.3). The other components of the
before a filter element change is required.
element perform the function of cleaning and preparing
the cooling passages while the corrosion inhibitors
If it is necessary for any reason to drain the cooling
protect them.
system before an element change, the treated water
should be saved and re-used. If the treated water is
Filter Installation
discarded, a new filter element must be installed since
If a water filter and conditioner is to be installed on an
the protective agents in the used filter will have been
engine which has been in service, drain and flush the
partially consumed in treating the discarded water.
cooling system prior to installation of the filter.
Service
Filter Maintenance
Whenever the water filter is removed and reinstalled, the
Replace the chemically activated element periodically
filter must have metal-to-metal contact (grounded), either
and buff the lower corrosion resistor plate on the former
directly with the mounting surface or through the
filter each time (discard the plate if excessive metal loss
mounting bolts.
or pitting is evident) to ensure effective protection of the
cooling system.
The current water filter includes a non-chromate type
element. This element can be used in place of either of
If the water filter is installed on an engine which has
the former water filter elements (permanent type
previously been in service, it may be necessary to
antifreeze or plain water type) and thus provides year
change the filter element two or three times at intervals
around cooling system protection. The current and the
of approximately 6,000 miles or less to clean up
former
water
filter
elements
are
completely
accumulations of scale and rust in the cooling system. It
interchangeable in the former filter can (refer to Section
is advisable to drain and flush the system during these
initial change intervals.
Replace the element and service the water filter and
Change the filter element periodically as outlined in
conditioner as follows:
Section 15.1.
1. Close the water filter inlet and outlet shut-off valves.
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