Leak detection with forming gas (X2 2018-2023)

Preliminary work needed: 

• If components of the refrigerant circuit are contaminated, clean the engine compartment. Otherwise, the sensor head of the leak detector will become contaminated  .

  COMPLY WITH NOTES AND INSTRUCTIONS ON HANDLING HIGH PRESSURE CLEANER .

• Refer to Drain off air conditioning system. Refer to SUCTION, EVACUATING AND FILLING AIR CONDITIONING (R1234YF)  .
• Fill the air conditioning with forming gas
• Set pressure to 5 bar

To reach the components of the refrigerant circuit with leak detector, specific parts must be removed depending on the vehicle.

Remove the following parts first immediately before the check of the respective components 

• Drive belt from air conditioning compressor
• Center fresh air grille
• Covers
• Trim panels
• Air ducts
• Intake silencer
• Firewalls
• Parts of the interior equipment (automatic rear air-conditioning system)

In some vehicles it is necessary to open the air flaps of the automatic air flap control.

Delete fault memory after filling the refrigerant circuit.

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Notes for handling the leak detector:

1. Sensor head should always stand vertical to the surface to be checked.
2. Sensor head must always be aligned to the center of the point to be checked. Slowly guide the sensor head around the point (e.g. connection point, sealing surface, etc.).
3. The optimal distance (A) between sensor head and surface to be checked should permanently be approximately 1 mm.

   Maximum distance (B) at points that are difficult to access approximately 5 mm.

4. Checking speed may not be more than maximum 2 cm per s.
   NOTE: If the leak detector displays a leak, remove the sensor head from the leak for approximately 10 s.
   Then check if the leak is still displayed at the same point. Repeat the process up to three times, to ensure that a leak is actually present at this point.
   NOTE: Replace the leaking component. Relieve the pressure from the refrigerant circuit prior to replacement.
   IMPORTANT: Compliance with the instructions above is absolutely mandatory!
   Non-compliance will significantly reduce the efficiency of leak detection!

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   NOTE: The graphic shows the example of the refrigerant circuit on the F02 with the automatic rear air-conditioning system optional equipment.
   Refrigerant circuits on other vehicles may differ from the graphic.

Overview of positions to be checked: 

1. Air conditioning condenser
2. Connection point between air conditioning condenser and refrigerant line
3. 1. Expansion valve, front (vehicles with and without automatic rear air-conditioning system)
   2. Expansion valve, rear (vehicles with automatic rear air-conditioning system)
4. Air conditioning compressor
5. Filler neck high pressure and low pressure
6. Refrigerant pressure sensor
7. 1. Refrigerant line, front (vehicles with and without automatic rear air-conditioning system)
   2. Refrigerant line, rear (vehicles with automatic rear air-conditioning system)
8. 1. Evaporator, front (vehicles with and without automatic rear air-conditioning system)
   2. Evaporator, rear (vehicles with automatic rear air-conditioning system)
   NOTE: Refrigerant line connection points are identified by arrows.

Checking sequence: 

1. Check of components 1, 2, 3a, 4, 5, 6, 7a and 8a of the automatic front air-conditioning system.

   If no fault found: 

2. Check of components 3b, 7b, 8b and connection points of the automatic rear air-conditioning system.

1. Air conditioning condenser: 

   Damage caused by stone chipping, etc. is the most frequent cause of air conditioning condenser leaks (1):

   1. Visual inspection in the area of the radiator grille (2) and air inlet grill, center (3).
   2. Check damaged points first.
   3. Check the remainder of the air conditioning condenser.

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2. Connection point capacitor - refrigerant line 

   Check the connection point between the connection at the air conditioning condenser (1) and refrigerant lines (2).

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3. Expansion valve: 

   Check the connection point between the expansion valve (1) and refrigerant lines (2).

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4. A/C compressor: 

   Remove drive belt from air conditioning compressor.

   Check the following components on the air conditioning compressor:

   1. High-pressure connection
   2. Low pressure connection
   3. Pressure relief valve
   4. Radial shaft seal of the magnetic clutch: Turn the magnetic clutch several times hand force during the leak detection.

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5. Filler neck 

   Blow out the fuel filler neck (1) prior to checking.

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6. Refrigerant pressure sensor 

   Check the sealing surface between the refrigerant pressure sensor (1) and the refrigerant line (2).

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7. Refrigerant lines: 
   1. Perform visual inspection
   2. Check damaged points first.
   3. Check bending points at points marked with an arrow. Leaks occur especially frequently at these points.
   4. Check the remainder of the refrigerant line.

      Courtesy of BMW OF NORTH AMERICA, INC.

8. Evaporator: 

   Remove the center fresh air grille.

   Compliance with the following settings is absolutely  required:

   • Recirculated-air mode On
   • Lowest blower speed
   • Lowest temperature
   • Set the air distribution to ventilation (air may only flow out of the center  fresh air grille)

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   Position sensor head (1) in air duct of middle fresh air grille (2) as illustrated and shift slowly from inside to outside above and below air flap (3).

   Carry out this operation on the left and right fresh air grilles.

   IMPORTANT: Some vehicles have an expansion valve directly next to the fresh air intake for the passenger compartment.
   In this case the expansion valve must be covered!

   Following the completed leak detection:

   • Refer to Evacuate and fill heating and air conditioning system. Refer to SUCTION, EVACUATING AND FILLING AIR CONDITIONING (R1234YF)  .