A/C Compressor, Removing And Installing: Installing
-- If the A/C compressor is replaced, check the ribbed belt for damage and if necessary replace. Refer to RIBBED BELT, REMOVING AND INSTALLING .
Install in reverse order of removal. Note the following:
-- Initiate the "A/C compressor first start" function in Guided Fault Finding. Refer to Vehicle Diagnostic Tester.
-- Clean the surfaces on the A/C compressor and bracket.
-- Insert the alignment sleeves -1- in the A/C compressor -2-.
Incorrectly installed alignment sleeves and dirty or damaged contact surfaces can cause alignment irregularities between the A/C compressor and engine. Alignment irregularities damage the A/C compressor over time.
If the A/C compressor is replaced because of complaints (for example, internal damage), then the refrigerant circuit must be cleaned. Refer to COMPONENTS, REPLACING or => Refrigerant R134a Servicing.
There is an unspecified amount of refrigerant oil in a removed A/C compressor, therefore observe the information about replacing the A/C compressor. Refer to COMPONENTS, REPLACING or => Refrigerant R134a Servicing.
For A/C Systems with Refrigerant R1234yf
If the A/C compressor is replaced, the following tables says if the refrigerant circuit must be flushed before the new A/C compressor is installed.
If flushing is necessity depends on the method of delivery and the refrigerant oil used before this.
| Replacement A/C compressor method of delivery | ||||
| Denso | Mahle/Delphi | Sanden | ||
| Method of delivery of A/C compressors installed in the vehicle | Denso | Do not Flush | Flushing | Flushing |
| Mahle/Delphi | Flushing | Do not Flush | Do not Flush | |
| Sanden | Flushing | Do not Flush | Do not Flush | |
-- If the table states that a refrigerant circuit flush is required. Refer to REFRIGERANT CIRCUIT, CLEANING .
All Vehicles
There is a risk of damaging the A/C compressor. Refrigerant oil may accumulate in the compression chamber when the A/C compressor is removed.
- After installing a new A/C compressor or filling with fresh refrigerant oil, turn the A/C compressor 10 times by hand before installing the ribbed belt.
Pay attention to the following when starting the engine for the first time after charging the refrigerant circuit:
-- Note the information for activating the A/C system after installing the A/C compressor. Refer to COMPONENTS, REPLACING or Components, Replacing .
-- Start the engine with the A/C compressor already turned off (indicator lamp button A/C is off) and wait until the idle RPM stabilizes.
-- Open the instrument panel vent.
-- Select for example the temperature preset "Lo" on the Heater and A/C Controls -EX21-.
-- Switch on the A/C compressor (indicator lamp in the A/C button turns on) and let the engine idle for at least five minutes.
The A/C compressor is driven by the ribbed belt pulley (there is no solenoid coupling).
If the A/C compressor is blocked, the compressor shaft overload protection is activated. The blockage is mostly recognized by deformations/bumps on the ribbed belt pulley. In addition, the blockage can be recognized by the abraded rubber in the area of the ribbed belt pulley.
The A/C compressor is supplied with a specific amount of oil that prevents the A/C compressor from becoming damaged when the refrigerant circuit is empty. This means that approximately 40 to 50 cm3 of refrigerant oil remains in the A/C compressor.
Only start the engine when the refrigerant circuit is charged.
Only start the engine if the refrigerant circuit was correctly installed. If, for example, the refrigerant lines are not connected to the A/C compressor and the engine is started and runs, then the A/C compressor may be destroyed by the build-up of internal heat.
A/C Compressor Regulator Valve -N280- is not activated when the refrigerant circuit is empty and the A/C compressor idles with the engine.
If it is necessary to start the engine with a discharged refrigerant circuit:
The refrigerant circuit must be fully assembled.
At least a quarter of the prescribed refrigerant oil must be in the A/C compressor.
The engine speed must not exceed 2000 RPM.
The engine should only run as long as absolutely necessary, maximum 10 minutes.