The Vari-Cool fan drive system accurately controls the speed of the fan in relation to the cooling requirements to maximize efficiency of the engine. The Vari-Cool system has two reasons why it is efficient: The belt drive that is used transfers almost 100 percent of the power from the engine to the fan. The variable fan speed sheave is electronically controlled only operating at a speed to cool the engine and other assisting components.
The Vari-Cool system is integrated into a hood design. When the air flows in and out from the coolers it is diverted to key openings in the hood structure. This allows for airflow dispersion that lessens the amount of dust and crop kickup. Therefore, helps discharge the airflow away from the cab.
The Vari-Cool system works through an electrohydraulic system that uses variables speed drives. The actual fan speed is determined by the ratio differences of the top fan drive sheave to the bottom sheave.
Inspections on your Vari-Cool fan drive should be made every 500 hours or annually. The majority of fan drive issues are caused by worn belts. Making a simple measurement can help you know if it is worn or not. Minimum width for a 9.0L engine belt is 29mm and minimum width for a 13.5 engine belt is 36mm. If the width of belt is at or below minimum measurements it will need to be replaced. Some symptoms of worn belts may include engine overheating and fan speed surging. Failure to replace a worn-out belt includes the system may generate Vari-Cool fan drive DTC's, clicking noise, and/or damage can occur to the driver and driven assemblies.
Stop by your local Martin dealer today to learn more!