What is the AC Low Pressure Hose all about? The AC system has many components: compressor, condenser, receiver dryer, evaporator, and hoses. For an AC system to work, it needs a gas or liquid substance, a refrigerant, (R-12 Freon in older cars, R-134a in 1995 and newer cars). Hoses carry the refrigerant throughout the AC system. A car usually has four or more hoses. The AC system hoses are connected to the evaporator, condenser, dryer, and the compressor. Due to normal wear and tear, the hoses can crack and leak refrigerant. Because the cracks cannot be sealed, you will need new hoses. Use the manifold gauge set to measure the pressures. Inspect the AC system for leaks. Remove refrigerant from the system. If an AC hose is leaking, remove and replace the hose(s). Evacuate and recharge the AC system. Check the car for system leaks. What common symptoms indicate you may need to replace the AC Low Pressure Hose?In these cases, when the AC system fails, you will not only NOT get any cold air, but the entire temperature regulation is thrown off.