TM 5-2420-230-24-2
General Information About Fans
Cooling System
Page 8-14
B Series Shop Manual
General Information About Fans
Warning: Never attempt to rotate the engine by pulling or prying on the fan. This practice can result in
serious personal injury and damage to the fan. Use only the proper engine barring techniques to manually
rotate the engine.
Check the fan for missing balance weights at each regular maintenance interval. Do not attempt to repair broken
or bent fans, or fans with missing balance weights.
Most equipment that has a Cummins engine uses a radiator and a fan. The radiator and fan transfer heat from
the cooling water to the atmosphere. The fan selection process must conclude that the fan, the fan mounting
arrangement, and the fan drive system are designed and matched for compatibility.
Upon request, Cummins Application Engineering Department will assist in determining the proper selection. Refer
any fan changes other than the direct replacement of a fan with precisely the same Cummins part number, to the
Cummins Application Engineering Department for prior approval.
Examples that require approval are,
1. Using an approved fan from one engine model on a different engine model.
2. Using an approved fan on an engine with a different fan mounting arrangement.
3. Using an approved fan on an engine with a different fan drive arrangement.
4. Converting an engine from one market model to another. An example is the conversion of a G-drive engine to
a power unit application.
5. Converting an engine model to a different model. An example is converting a 6BT5.9 to a 6BTA5.9.
This list is not inclusive. Always contact Application Engineering for assistance.
At times an existing fan can yield ONLY marginal cooling capability when being considered for a new application.
Caution: Never repitch (bend) the blades to obtain additional air delivery. Bending the blades or spider
creates stress in the material used for the construction of the fan. Repitching (bending) will cause fan
failure. The proper diameter fan must be selected. Never modify an existing fan.
Application Engineering will provide assistance in the selection of a fan with the correct pitch and diameter for
proper cooling.
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