Attention: Any repair and maintenance of the air conditioning system must be carried out in specialized workshops. Do not trust your car to self-taught craftsmen.
When assembling joints, always use new O-rings soaked in clean 525 viscosity coolant oil. It is much easier to assemble parts lubricated with oil, and the oil will also seal the joints. When tightening connections, use a second wrench to hold the fixed parts of the connection more firmly. This way you can guarantee the strength of the assembly.
O-ring replacement
Each time you remove a joint or fitting, you must install new o-rings to replace in the A/C system, unless these o-rings are already installed on new parts. Although all o-rings look the same, it is extremely important to use only those that are recommended for replacement in the A/C system when changing, otherwise refrigerant leakage may occur.
When replacing O-rings (A) on parts of the air conditioning system, it is necessary to accurately determine the configuration of the fitting so that the ring to be replaced matches the contour of the part. Some butt joints and parts have so-called «grabbing» fittings where there are grooves (IN) to hold o-rings, but there are also those where there are no grooves, and are used «gripless» or «standard» sealing rings.
The mounting and tightening process is the same for both designs, but the O-rings are different.
Before installation, also check that neither the rings nor the fittings are damaged or deformed. Deformed or damaged parts must be replaced.
Maintenance of lines and fittings of the cooling system
Flexible hose lines must not be twisted to a radius greater than four times the hose diameter.
Flexible hose lines should be inspected regularly as leaks can occur due to brittleness, and replaced with new lines if a leak or line break is found.
Before disconnecting the fitting in the cooling system, you must first drain all the refrigerant. This must be done very carefully, regardless of the sensor readings. Open the system very slowly, keeping your face and hands away so as not to damage them if liquid refrigerant suddenly appears in the line. If you notice that the refrigerant is under pressure when you loosen the fitting, first relieve the pressure as described when unloading the A/C system.
If you find that one of the refrigeration lines is open, put caps or screw it back on immediately to prevent moisture and dirt from getting in, which can cause wear on the internal parts of the compressor or lead to blockage of the lines, condenser and evaporator core tubes, expansion (diverting) tubing or compressor inlet filters.
The appropriate wrenches must be used when making connections on o-ring fittings. To prevent twisting of connecting lines or components, always use a wrench to support the fitting located on the opposite side. When connecting flexible hose connectors, it is important that the stamping fitting and flare nut, as well as the coupling to which they are attached, are held simultaneously by three different wrenches, which will prevent the fitting from rotating and prevent damage to the main socket.
O-rings and sockets must always be in excellent condition. A burr or piece of dirt may cause refrigerant leakage. When changing the O-ring, dip it first in clean 525 viscosity coolant oil.
The location of the elements of the air conditioning system on the car (late car models)
1 - vehicle speed sensor;
2 - temperature sensor;
3 - capacitor;
4 - working fitting;
5 - compressor;
6 - expansion tube.