Lubricating the air conditioning compressor (amount of refrigerant oil in new air conditioning compressor known)

• Step 1 
• Read and note the amount of refrigerant oil on the removed air conditioning compressor.

  (If no label is present, continue with step 3  , case 1.) 

• Read and record amount of refrigerant oil specified on the new air conditioning compressor.
• Compare both amounts of refrigerant oil with each other: 

  Different cases: 

  • Amount of refrigerant oil on the removed and new air conditioning compressor is same.  In this case, continue with step 3, case 1. 
  • Amount of refrigerant oil on the removed and new air conditioning compressor is not the same: 

  Different cases: 

  • Amount of refrigerant oil on the removed air conditioning compressor is higher  than on the new air conditioning compressor. Difference is not taken into account. In this case, continue with step 3, case 1. 
  • Amount of refrigerant oil on the removed air conditioning compressor is lower  than on the new air conditioning compressor: Generate and record the difference between both amounts of refrigerant oil. Then, continue with step 3, case 2. 

  Example:
  Amount of refrigerant oil on removed  air conditioning compressor 110 g
  Amount of refrigerant oil specified on the new  air conditioning compressor 150 g
  150 g -110 g = 40 g approximately 40 mL
  Record the difference 40 mL.

• Step 2 
• Mechanical air conditioning compressor (removed): 
• Open the oil filler plug.
• Drain all of the refrigerant oil remaining in the removed  air conditioning compressor into a measuring cup via the oil filler plug.
• Turn the belt pulley during draining.
• Electric A/C compressor with oil filler plug (removed): 
• Open the oil filler plug.

  Courtesy of BMW OF NORTH AMERICA, INC.

• Drain all of the refrigerant oil remaining in the removed  air conditioning compressor into a measuring cup via the oil filler plug.
• Electric A/C compressor without oil filler plug (removed): 
• Remove the dummy plugs from the high-pressure connection and the low pressure connection.
• Completely drain the refrigerant oil remaining in the removed  air conditioning compressor into a measuring cup via the high-pressure connection and low pressure connection. 
• Step 3 
• Inspect the refrigerant oil drained from the removed air conditioning compressor in the measuring cup. 

  If no refrigerant oil escapes from the removed air conditioning compressor, inspect the extracted refrigerant oil in the collecting vessel of the A/C service station. 

• No swarf is present in the drained refrigerant oil. Additional work is not necessary.
• Swarf is present in the drained refrigerant oil.

  In addition to the air conditioning compressor, replace the following parts: 

  • Air conditioning condenser
  • Desiccant insert (if it can be replaced individually, if not air conditioning condenser)
  • Line to the air conditioning condenser
  • Refrigerant oil
  • All expansion valves
  • BEV, PHEV: In addition, flush the refrigerant circuit.
• Step 4 
• Read the drained amount of refrigerant oil from the removed air conditioning compressor on the measuring cup.

Case 1: 

• Add 10 mL extra to the amount of refrigerant oil read as a precautionary allowance. 

  Courtesy of BMW OF NORTH AMERICA, INC.

• Record at least but a total of 50 mL. 

  Example:
  20 mL read at measuring cup:
  20 mL + 10 mL precautionary allowance = 30 mL <50 mL
  Determined amount of refrigerant oil for new air conditioning compressor = 50 mL

  Courtesy of BMW OF NORTH AMERICA, INC.

Case 2: 

• Add 10 mL extra to the amount of refrigerant oil read as a precautionary allowance. 
• To this add the difference. 
• Record at least but a total of 50 mL. 

  Example:
  Difference = 40 mL
  20 mL read at measuring cup:
  20 mL + 10 mL precautionary allowance = 30 mL
  30 mL + 40 mL difference = 70 mL > 50 mL
  Amount of refrigerant oil determined for the new air conditioning compressor = 70 mL

• Step 5 
• Mechanical air conditioning compressor and electric A/C compressor with oil filler plug (new): 
• Open the oil filler plug.
• Drain the amount of refrigerant oil specified in the table from the new  air conditioning compressor into a clean measuring cup via the oil filler plug.
• Electric A/C compressor without oil filler plug (new): 
• Remove the dummy plugs from the high-pressure connection.
• Drain the amount of refrigerant oil specified in the table from the new  air conditioning compressor into a clean measuring cup via high-pressure connection. 

  Courtesy of BMW OF NORTH AMERICA, INC.

  Amount of refrigerant oil to be drained from the new air conditioning compressor = amount of refrigerant oil on the label for the new air conditioning compressor - amount of refrigerant oil determined for the new air conditioning compressor

  Example:
  Amount on the new air conditioning compressor refrigerant oil label: 150 mL
  Amount of refrigerant oil determined for new air conditioning compressor: 50 mL
  Amount of refrigerant oil to be drained = 150 mL -50 mL = 100 mL
  100 mL must be drained from the new  air conditioning compressor

• Mechanical air conditioning compressor and electric A/C compressor with oil filler plug (new): 
• Replace the sealing ring.
• Tighten oil filler plug.
• Electric A/C compressor without oil filler plug (removed): 
• Seal the high-pressure connection with dummy plug.
• The drained, new refrigerant oil must be filled into the A/C service station expansion tank immediately  after draining.
• Drained, new refrigerant oil must be disposed of correctly if it is not immediately refilled into the A/C service station expansion tank.
• Refrigerant oil drained from the previous air conditioning compressor must not be reused and must be disposed of correctly.