Perkins 1200F Series Supplement Manual page 30

5.2.1.1 General Coolant Line recommendations
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The coolant hoses should be standard coolant hose material.
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The hoses must be as short and direct as possible with minimal bends to reduce
restriction.
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The hoses must not contain any dips or sags which may encourage air entrapment.
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The hoses should be adequately supported to prevent vibration and must not pre-load
the connector with side loads or moments. The recommended distance between the
support device and the connector point is a maximum of 200mm.
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The coolant hoses must be free from fouling, abrasion and should be routed clear or
shielded from excessive heat sources.
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The use of hose retaining/positioning clamps should be designed and controlled to
prevent coolant flow restriction.
5.2.1.2 Coolant supply Line De-aeration
A risk to the DEF coolant circuit is the trapped air in the long lines used in applications where the
DEF tank is installed far away from the engine coolant outlets.
When the engine is first filled, it is possible to trap air in coolant lines to the DEF tank and this
trapped air should be vented over time through Engine operation. It is best, however, to reduce the
amount of trapped air in the lines in the first place so it doesn't affect the effective running of the
emission critical components.
Ideally, the DEF tank should be installed no higher than the engine for effective filling. However,
where this is not possible, it is recommended that it is placed no higher than 1m above the coolant
feed point.
In the applications where these recommendations are exceeded, it may be required to employ
additional measures to vent the cooling lines. The following methods may be used.
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Bleeding the lines manually by unplugging them from the DEF components to let the air out
Bleeding the lines manually by installing a bleed valve to the lines, the valve location should
be as close to the DEF component as possible. The valve must not restrict the flow when it
is not used and care should be taken to ensure they are not left open.
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It may also be necessary to run a venting procedure – testing should be conducted to
establish the acceptable method.
A&I manual Publication TPD 1832 – Production issue 3.
1204F - DEF System Supplement
Page 30 of 41