General information about R-134a refrigerant
Because R-134a refrigerant is a fluorocarbon (HFC in which chlorine atoms are replaced by hydrogen atoms), then it does not have a harmful effect on the ozone layer of the atmosphere. To protect the ozone layer, Mitsubishi Motors Corporation recommends the use of dedicated R-134a refrigerant recovery devices.
R-134a refrigerant is a clear, colorless substance in both liquid and gaseous phases. Since the boiling point of the refrigerant at atmospheric pressure is -29.8°C, then under normal conditions of temperature and pressure, it is in a gaseous state. This gas is heavier than air and is not flammable or explosive.
Security measures
Attention: errors during maintenance can lead to damage or unintentional activation of the additional restraint system (SRS). Before carrying out maintenance and repair work, read and follow the instructions in the relevant section in chapter "SRS passive safety system".
1. Maintenance of the air conditioning system.
Caution: Always wear safety goggles when servicing air conditioning systems.
At normal temperatures and atmospheric pressure, the rate of evaporation of R-134a liquid refrigerant is so high that any object that comes into contact with it freezes. Therefore, special care must be taken when handling liquid refrigerant to avoid contact with the skin and, in particular, with the eyes. Always wear safety goggles when servicing the refrigerant part of the air conditioning system. Also keep a bottle of clean, sterile mineral oil handy (Vaseline oil). If liquid refrigerant gets into your eyes, rinse immediately with a few drops of mineral oil. The oil quickly absorbs the refrigerant. Then rinse your eyes with plenty of cold water. Even if after these procedures the irritation has stopped, seek medical help immediately.
2. Refrigerant charge.
Attention: do not heat the refrigerant above 40°C.
When charging the system with refrigerant, in most cases moderate heating of the refrigerant cylinder is required to create an increased pressure in the cylinder compared to the pressure in the air conditioning system. For this purpose, a large container is usually used, filled with warm water with a temperature not exceeding 40°C. Do not use a blowtorch, torch, etc. to heat the refrigerant bottle, as the pressure and temperature of the refrigerant may then exceed the above limit temperature. Do not weld or hot-steam clean parts located in close proximity to the components and hoses of the air conditioning system.
The amount of refrigerant is 550±20 g.
3. Adding refrigerant.
Attention: when charging the air conditioning system, the refrigerant cylinder must be in a vertical position.
If the refrigerant cylinder is lying down or turned with the valve down, the refrigerant in the liquid phase will enter the air conditioning system and damage the compressor.
4. Search for refrigerant leaks.
Caution: Always work on the air conditioning system in well ventilated rooms.
Note: A special refrigerant leak detector R-134a should be used to check for gas leaks in the air conditioning system.
5. Features of polished and chrome finishes.
Caution: Do not allow liquid refrigerant to come into contact with polished metal surfaces.
When liquid coolant gets on polished and chrome-plated surfaces, they lose their luster and tarnish, and the combination of coolant with moisture can lead to corrosion on the entire metal surface.
6. Replacement parts.
A) Remove the refrigerant from the system before removing parts.
b) Openings of disconnected parts should be immediately plugged to prevent moisture, dust and other contaminants from entering.
V) Do not store the condenser or receiver dryer without plugs.
G) Before installing a new compressor, remove the refrigerant through the charging valve, otherwise the compressor oil will leave the system with the refrigerant when the plug is removed.
d) Do not use a blowtorch to bend or lengthen pipes, as a layer of oxides forms on the tubes, clogging the system.
e) When tightening the nuts, use two wrenches to prevent twisting of the pipes.
and) Use O-rings and glands designed for R-134a refrigerant only.
Working with tubes, hoses and connections
1. Kinked hoses or sharp kinks in the air conditioning pipes greatly reduce the efficiency of the system.
2. When the air conditioner is operating, high pressure is created in the system, so special attention should be paid to the reliable tightening of all connections. If the air conditioning system is depressurized (when replacing or repairing parts and assemblies), foreign matter and moisture may enter.
3. The following precautions must be observed when maintaining and repairing the air conditioning system.
A) Before disconnecting any air conditioning connection (or replace parts), it is necessary to completely pump out the refrigerant from the system. Unscrew the connections of the air conditioning system carefully, even after pumping the refrigerant out of the system. If there are signs of high pressure when loosening any fitting, wait and relieve the pressure very slowly.
b) Never attempt to bend already bent tubes during assembly. When laying flexible hoses, observe the rule that the bending radius of the hose is at least 10 hose diameters.
V) Sharp kinks in the hoses reduce the volume flow of the refrigerant. Flexible hoses must not run closer than 80 mm from the engine exhaust manifold.
G) Flexible hoses must be checked for condition and proper installation at least once a year.
d) All o-rings of standard air conditioning connections are non-reusable.