Connection with bolts and nuts
Pic. 8.56. Air conditioning piping connection
Apply compressor oil to all fasteners to facilitate tightening just enough to ensure a tight seal.
To prevent twisting of pipelines, tighten with two wrenches.
Tighten screw connections to the specified torques.
Flange connections with guide pin
Check the presence of the O-ring, make sure it is not damaged and apply compressor oil to it.
Pic. 8.57. Scheme of installation of flange connections
Insert the tube as shown in Figure 8.57 and tighten the nut by hand.
Compression oil
Oil for lubricating the compressor during its operation circulates in the system. Whenever parts of the system are replaced or a large amount of refrigerant leaks, add oil to restore its original amount.
One-time oil filling: 140-160 g.
Oil Handling
Do not allow moisture, dust, metal particles, etc. to enter the oil.
Do not mix oils of different brands.
When the oil is exposed to air for a long time, the moisture content in it increases. After refueling and adding oil, close the container tightly immediately.
Filling the compressor with oil
Before checking the oil level and topping up, let the engine idle for 20-30 minutes, setting the temperature switch to the position corresponding to the maximum cooled air supply to the passenger compartment, and the fan switch to the maximum speed, then fill the compressor with oil.
Checking and restoring the compressor oil level
To add oil with the compressor running, first check the oil level.
Fill the compressor with oil, stop the engine, drain the refrigerant and remove the compressor from the vehicle.
Drain the oil through the drain fitting of the system.
Note. Draining oil from a cold compressor is difficult. Before draining the oil, warm up the compressor to approximately 40-50°C.
Determine the amount of drained oil. If it is less than 70 cm3, then there is a small oil leak. Check all system connections for leaks, repair leaks or replace faulty parts as necessary.
Check the oil for contaminants and restore it to normal level as indicated below.
Adding oil when replacing parts
When replacing parts of the system, add the following amount of oil to the parts to be replaced.
Setting control points
Pic. 8.58. Connecting the filling hoses
Close both valves on the pressure gauge adapter.
Attention! When installing control pressure gauges, observe safety precautions.
Attach the charging hoses to the fittings of the adapter. Connect the low pressure hose to the low pressure filling port and the high pressure hose to the high pressure filling port. Tighten the hose fitting nuts by hand.
Note. Charge the system with refrigerant after removing the engine cover and air intake.
Draining the refrigerant
Connect a set of test gauges to the system.
Lay a towel under the open end of the center hose.
Drain the refrigerant by slowly opening the high pressure valve.
Note. If the refrigerant is drained too quickly, the compressor oil may drain from the system.
Check for oil stains on the towel. If so, close the valve slightly.
When the gauge reading drops below 3.5 kgf/cm2, slowly open the low pressure line valve.
Slowly open the high and low pressure valves until the pressure gauges show 0 kgf/cm2.
Pic. 8.59. Setting diagram when draining the refrigerant