Do you need a cdl to drive an air brake vehicle that is under 26000 lb gross vehicle weight in mighigan?

No. Air brakes are not a factor in determining whether or not a CDL is required in any state. The only instance in which you would need a CDL is in cases where the vehicle is transporting an amount of hazardous materials which requires the display of placards, or when it's a bus designed to transport more than 15 persons (including the driver).