STICK AR 3905104 - Caterpillar

discourages the use of airflow restriction devices that are mounted in front of radiators. Airflow restriction can cause the following conditions:
High exhaust temperatures
Power loss
Excessive fan usage
Reduction in fuel economyReducing air flow over components will also affect under hood temperatures. Reducing air flow can increase surface temperatures during an aftertreatment regeneration and could affect component reliability.Reducing air flow can increase surface temperatures during an aftertreatment regeneration and could affect component reliability.If an airflow restriction device must be used, the device should have a permanent opening directly in line with the fan hub. The device must have a minimum opening dimension of at least 770 cm2 (120 in2).A centered opening that is directly in line with the fan hub is specified in order to prevent an interrupted airflow on the fan blades. Interrupted airflow on the fan blades could cause a fan failure.