Car air conditioning: Refrigerant and oil capacity (user:rde-groups CONTAINSANY 'XVIP_AMC_UK' AND user:rde-groups CONTAINSANY 'XHTW_Wholesaler')
Car air conditioning: Refrigerant and oil capacity
 
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Car air conditioning: Refrigerant and oil capacity

Which filling quantities for which vehicle? Our current manual refrigerant and oil filling quantities covers most of today's common vehicles and answers exactly this important question.

 

You will also find additional technical information here, e.g. the operation of an air conditioning system with an expansion valve, safety information, instructions for the proper handling of refrigerants and hints on removing and installing an air conditioning system, and you can also download the latest manual on refrigerant and oil volumes.

 

Important note:
The following technical information and practical tips were created by HELLA to support professional automotive garages in their daily work. The information presented here on this website should only be used by trained automotive technicians taking the respective safety regulations and country-specific legislation and practice into account.

 

Refrigeration cycle: How the air conditioning system with expansion valve works

 
 
 

For controlling the climate in the vehicle interior, refrigerant circuit as well as coolant circuit are required. A mixture of cold and warm air allows the generation of the desired climate conditions - completely independently from outer conditions. As a result, the air conditioning system becomes an important factor for safety and driving comfort.

 

The individual components of the refrigerant circuit are connected by tubes and/or aluminium pipes and thus form a closed system. Refrigerant and refrigerant oil circulate in the system, driven by the compressor. The circuit has two sides:

  • The section between the compressor and the expansion valve is the high pressure side (yellow/red).
  • The section between the expansion valve and the compressor is the low pressure side (blue).

The gaseous refrigerant is compressed by the compressor (thereby significantly increasing its temperature) and pressed under high pressure through the condenser. This removes heat from refrigerant - it condensates and changes its state from gas to liquid.

 

The filter dryer, the next unit, removes contaminants and air from the liquid refrigerant as well as humidity. This ensures system effectiveness and protects the components from damage caused by contaminants.

 
 
 
 
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Car air conditioning recharge: Safety information and handling of refrigerant

 
 
 
  • Always wear safety glasses and safety gloves! Under normal atmospheric pressure and at ambient temperatures liquid refrigerant evaporates so suddenly that contact with skin or eyes may cause frost damage to the tissue (risk of blinding).
  • In the case of contact, rinse the affected locations with plenty of cold water. Do not rub. Immediately seek medical attention!
  • When working on the refrigerant circuit the work-place must be well ventilated. Inhalation of high concentrations of gaseous refrigerant causes dizziness and danger of suffocation. Work on the refrigerant circuit may not be performed from working pits. As gaseous refrigerant is heavier than air, it can there accumulate in high concentrations.
  • Do not smoke! Cigarette embers can break down refrigerant into toxic substances.
  • Refrigerant must not contact open fire or hot metal. Deadly gases may be generated.
  • Never allow refrigerant to escape into the atmosphere. If the refrigerant container or the air conditioning system are opened, the content discharges under high pressure. The pressure amount depends on the temperature. The higher the temperature is, the higher is the pressure.
  • Avoid any head impact on components of the air conditioning system. After paintwork, vehicles must not be heated above 75 °C (drying furnace). Otherwise, the air conditioning system must be drained first.
  • When removing the service tubes from the vehicle, the connections must not be pointed towards your body. Refrigerant residues may leak.
  • When cleaning the vehicle, the steam-jet cleaner must not be directly pointed onto parts of the air conditioning system.
  • Never change the factory setting of the adjusting screw on the expansion valve.

 

 
 
 
 

 
 
 

Removal and installation instructions: Air conditioning system

 
 
 

Prior to removal and/or installation of the spare part it must be verified that connections, fixings and other installation-relevant properties are identical.

 

When replacing components, always use new O-rings suitable for the refrigerant.

 

The compressor oil has a strong hygroscopic effect. Thus, the system must be kept closed if possible and/or the oil is to be filled shortly prior to closing the refrigerant circuit only.

 

Prior to the installation, O-rings and seals are to be greased with refrigerant oil or special lubricants in order to facilitate installation. No other greases or silicone spray may be used as this results in immediate contamination of the new refrigerant.

 

For every opening of the refrigerant circuit the dryer must be replaced due to its strong hygroscopic effect. If dryer or accumulator are not replaced on a regular base, the filter pad may decompose and silicate particles may be distributed in the entire system and cause severe damage.

 
 
 

The system connections should never remain open for an extended period of time, but should be immediately closed using caps or plugs. Otherwise, liquid would be entered together with air into the system.

 

In order to avoid damage to connection pipes and/or components, always use two wrenches when loosening and fastening the connections.

 

When routing tubes and cables make sure that no damage is possible caused by vehicles edges or other moving components.

 

When replacing a component of the air conditioning system, the correct oil quantity in the system is to be ensured. Oil must be refilled or drained as needed.

 

Prior to refilling the system, it must be checked for leaktightness. Next, the system is to be sufficiently evacuated (approx. 30 minutes) in order to ensure that all humidity is removed from the system.

 

After filling the refrigerant quantity specified by the vehicle manufacturer, the system is to be checker for proper function and leak-tightness (electronic leak indicator). At the same time, the high and low pressure values must be observed using pressure manometers and compared with the specified values. Compare the outflow temperature on the centre vent with the values specified by the manufacturer. After the service connections are fitted with protective caps, the maintenance due date is to be indicated on an adhesive service label on the front cross member.

 
 
 

Information regarding the installation of air conditioning system compressors

Make sure that all contaminations and foreign substances are removed from the refrigerant circuit. For this purpose, the system is to be flushed prior to installing the new compressor. Depending on the level of contamination, refrigerant R134a or a special flushing solution is suitable for flushing. Compressors, dryers (accumulators), expansion valves and/or orifice tubes cannot be flushed. As it must always be assumed and cannot be ruled out that the system is contaminated (abrasion, swarf) when a compressor is defective, the system must always be flushed when this component is replaced. Make sure that no flushing solution residues remain in the system. Dry the refrigeration circuit using nitrogen as needed.

 

Replace the filter dryer or accumulator and the expansion valve or orifice tube.

 

As one and the same compressor can potentially be used for different vehicles or systems, the oil filling quantity and viscosity must be checked and/or corrected according to the manufacturer's specifications before installing the compressor. All the oil must be siphoned off and collected. The compressor must then be newly filled with the entire oil quantity specified by the vehicle manufacturer (system oil quantity).

 

The compressor must be spun 10 x by hand before being installed to ensure the oil is distributed evenly. When installing the drive belt it must be ensured that it is aligned. Some compressors are designed for so-called "multiple applications". This means that they can be installed in different vehicles. Except the number of grooves on the magnetic clutch, there is 100% agreement with the "old part". After compressor installation and new filling of the refrigerant circuit, the engine should first be started and operated for several minutes at idling speed. Further specifications (instruction leaflets, manufacturer's specifications, run-in specifications) are to be separately observed.

 
 
 

Refrigerant and oil filling quantities: PDF download