Refrigerant Recovery And Recharging (R-1234y)

Mobile Repair Possible: No

Special Tools Required:

A/C Vacuum and Recharge System - No part Number

A/C Leak Detector Kit - No part number

WARNING: Refrigerant System hazard
Failure to follow specified procedures may result in serious injury due to freezing temperatures associated with leaking refrigerant

Only properly trained and authorised persons may carry out work on air conditioning systems.
Always use personal protective equipment (PPE).
Always read and understand the A/C Service Station operator's manual before operating the machine.
Warning - At higher temperatures R-1234yf is flammable!
R-1234yf is a hazardous liquid and can cause serious injury if handled incorrectly. Protective clothing must be worn, consisting of safety glasses, lint-free gloves and overalls. Do not use the A/C Service Machine in the vicinity of spilled or open containers of flammable liquids. BE AWARE OF FIRE HAZARDS.
Do not breathe refrigerant and lubricant vapor/mist. Exposure may cause personal injury to eyes and respiratory system. All work to be performed in a well-ventilated area. If accidental discharge occurs, ventilate the work area before recommencing work. Further safety information can be found on A/C work equipment being used, refrigerant and lubricant containers. Refer to their instruction manuals and MSDS (Material Safety Data Sheets).
All open A/C components must be sealed immediately. Care must be taken to make sure all A/C components are clean.
An Oil Balance is to be conducted on parts that are replaced. Refer to APPROXIMATE FLUID CAPACITIES AND SPECIFICATIONS
Only use VinFast specified refrigerant and the correct refrigerant oil specified for that vehicle. Vietnam market uses R-134a. US/Europe market uses R-1234yf. The Air Conditioning Service Station should only be used on VinFast vehicles with specified refrigerant. DO NOT MIX Refrigerant types such as R-134a and R1234yf. DO NOT MIX Refrigerant Oil types such as PAG Oil, PVE Oil and POE Oil. Each VinFast vehicle uses different Refrigerant Oil. VFe36 with R-1234yf (US/Europe) uses PAG Oil. For Refrigerant Oil type and specification refer to APPROXIMATE FLUID CAPACITIES AND SPECIFICATIONS
If the Air Conditioning Service Station is not solely dedicated to a VinFast Model such as VFe36, then before every service the machine must undergo an internal self-flushing of the A/C lines to prevent cross-contamination. Refer to the Operation Manual of the A/C Service Station on how to conduct the self-flushing procedure.

Vehicle Preparation:

Depending on the region, the correct refrigerant must be recovered and recharged.

Vietnam market uses R-134a. US/Europe market uses R-1234yf.

Set HVAC controls to foot mode, maximum blower, RECIRC, full hot and A/C ON to heat the HVAC system.
Run the vehicle with A/C ON for 5 minutes (to circulate the refrigerant within the system).
Turn the A/C OFF (Compressor OFF) and keep the Blower ON (while recovering the refrigerant). With the same settings as Step 1 except A/C OFF to ensure the evaporator is warm. This is to prevent oil from chilling and forming a virtual barrier to reduce refrigerant evaporation.
Removal note: A warm engine bay and evaporator will allow maximum refrigerant recovery.

Typically, approximately 19% of refrigerant can stay trapped with the refrigerant oil at 21°C ambient, after the recovery, if the HVAC system heating initiation process is not conducted. The cooler the ambient, the more refrigerant will be trapped within the refrigerant oil.

Preliminary A/C Service Station Inspection Before Commencing:

Courtesy of VINFAST, LLC

Make sure that the A/C Service Station (1) refrigerant storage (2) has sufficient refrigerant for charging the system (normally minimum 2 kg).
Drain the oil collection reservoir on the A/C service station - refer to "Warning".
Recover any remaining refrigerant left in the lines on the A/C Service Station so that both gauges show negative pressure.
Turn both Discharge (RED) and Suction (Blue) hoses from the A/C Service Station to the OFF or closed position.
Connect the Discharge (RED) and the Suction (BLUE) hoses from the A/C Service Station to the vehicle A/C system charging ports, using the quick connect shut off valves (3) & (4) fitted to the end of the hoses.

Refrigerant-Recovery:

Turn the A/C Service Station to ON position (remember vehicle should be on with the A/C OFF as per vehicle preparation procedure).
Select the refrigerant recovery program at the control panel.
Slowly open the taps on the quick connect shut off valves by not more than a quarter of a turn more from when you start to see a pressure reading on the A/C service centre. This is to minimise oil being drawn from the system.
Start the recovery operation. Slightly open the Suction (blue) hand valve on the A/C service station. When the discharge gauge pressure reaches 250kPa, open the discharge (red) hand valve to complete the recovery operation. This is to minimise the chance of drawing oil out and reduce the cooling effect when the refrigerant being drawn from the system (as explained in Vehicle Preparation).
The refrigerant will go to the storage bottle and the oil will be separated into a removable oil reservoir. Measure the amount of oil removed and remember to replace it, as per step 3 in System Evacuation.
The recovery will be completed when a partial vacuum is achieved (normally - 20kPa).
Repeat the recovery operation ONCE more if the pressure increases after a few minutes.
Record the refrigerant quantity in the A/C Service Station Log book to maintain the records.

System-Evacuation:

Fully open both discharge and suction quick connect shut off valves, open both hand taps on the A/C service station.
Evacuate the system for a minimum 30 minutes.
Remember to inject the oil amount found in the oil reservoir during the recovery process before charging the system (see step 1 - refrigerant charging procedure).
Shut both valves on the service centre and check if the vacuum is maintained. A well-sealed system should reach - 90 to - 100kPa.
If the vacuum is maintained, then the system can be recharged. If not, leaks must be found and fixed.

Refrigerant Charging Procedure:

Refrigerant Oil - Check the oil reservoir if any oil was evacuated during the "System Evacuation" step. If the system was opened, due to a part replacement, add the oil via a beaker (measuring container) into the part you have opened - refer to APPROXIMATE FLUID CAPACITIES AND SPECIFICATIONS
for correct oil amount.

If the system remains sealed, inject oil using the A/C Service Station).
Connect both discharge and suction quick connect shut off valves (3) & (4) to the charge ports on the vehicle. (See image)
Open both quick connect shut off valves.
Select Charging Program and the charge amount at the A/C Service Station. Refer to APPROXIMATE FLUID CAPACITIES AND SPECIFICATIONS
Start Charging the system until the A/C Service station shows the charging process is completed. Close the Discharge (high side) hand valve on the A/C service centre.
Start the car and turn the A/C ON.
Shut the discharge (RED) quick connect shut off valve and remove the discharge line from the vehicle. Open the discharge hand valve on the A/C Service Station and wait for the pressure to equalize between high and low.
Stop the process.
During low ambient conditions (<10°C) the full charge may not be achieved without turning the A/C ON, due to insufficient pressure in the refrigerant bottle.
CAUTION: Only charge through the suction side when the vehicle is ON & A/C ON, with the high side quick connect closed (There will be an oil circulation through the A/C Service Station if the high side valve is open).
Remember to recover all refrigerant in the lines before turning A/C Service Station off.
Update the A/C Service Station Log book with the vehicle identification and quantity of refrigerant applied.