A-79840-AI Expansion Valve (block type)One New Aftermarket Replacement Expansion Valve (Block Type) for Deutz and Fits Allis Chalmers Tractors This block type A C expansion valve regulates refrigerant flow into the evaporator core, a key component of the cab air conditioning system on Deutz and Fits Allis Chalmers tractors. The block type design mounts directly at the evaporator inlet and outlet connections for a precise, leak free fit. Compatible Models Deutz Tractors: DX8. 30, DX90,