The vacuum pump in your Dodge Ram Cummins is responsible for brakes, 4wd, and interior vent operation. Being this pump is operated by a gear in the front gear case, it needs proper oil flow to ensure the bearings are lubricated. If your oil supply line is leaking, this can cause the vacuum pump to fail and subsequently halt the operation of vital components. Replace your failed vacuum pump supply line with a genuine Cummins Replacement Vacuum Pump Oil Supply Line. This is a direct replacement line and is designed to meet or exceed factory specifications.