Hoses, Pipe, O-Rings
The A/C system contains a number of pipes and hoses that join the different components and transport the refrigerant.
Hoses and pipes
There are three hoses and a pipe system in the engine compartment
- The suction hose (1) transports the refrigerant in gaseous state, low pressure, from the side member to the compressor
- The pressure hose (2) transports refrigerant in gaseous state, high pressure, from compressor to condenser
- The liquid hose (3) transports refrigerant in liquid state, high pressure, from condenser to side member
- The pipe system ("side member pipe") (4) joins suction hose and liquid hose with the expansion valve. Service valves (5), IHX (internal heat exchanger) (6) and expansion valve (TXV) (7) are installed on the side member pipe.
A/C pipes and hoses in the engine compartment
Rear A/C pipe
On cars with rear A/C climate units, there are extra low pressure hoses (8) and high pressure hoses (9) that connect the side member pipe to the connection in the firewall as well as pipe system (10) through the passenger compartment to rear evaporator.
All pipe sections are made of aluminum. Low pressure pipes to the rear A/C climate unit are equipped with condensation protection in order to prevent moisture condensing on the surface of the pipe (due to cold refrigerant) and leading to moisture and corrosion on surrounding components. When servicing rear A/C pipes or surrounding components, check that the condensation protection is undamaged.
All connections in the A/C coolant system have double O-rings as seal. All pipe connections of the male type have protective plastic rings ("soft nose") at the far end. These rings can be replaced at a system service.
O-rings
The O-rings are made of a specially developed material (HNBR = hydrogenated nitrile rubber). It is important that only O-rings approved by Volvo and intended for use with R134a, R1234yf and specific compressor oil are used at a system service.
O-rings must always be changed during service and lubricated with compressor oil.