Discharging & Evacuating System
Recovery, Recycling, Evacuation and Charging of HFC-134aAir conditioning Systems contain HFC-134a. This is a chemical mixture which requires special handling procedures to avoid personal injury.
- Always wear safety goggles and protective gloves.
- Always work in a well-ventilated area. Do not weld or steam clean on or near any vehicle-installed air conditioning lines or components.
- If HFC-134a should come in contact with any part of the body, flush the exposed area with cold water and immediately seek medical help.
- If it is necessary to transport or carry any container of HFC-134a in a vehicle, do not carry it in the passenger compartment.
- If it is necessary to fill a small HFC-134a container from a large one, never fill the container completely. Space should always be allowed above the liquid for expansion.
- HFC-134a and R-12 should never be mixed as their compositions are not the same
- HFC-1 34a PAG oil tends to absorb moisture more quickly than R-12 mineral oil and, therefore, should be handled more carefully.
- Keep HFC-134a containers stored below 40 °C (100 °F).
WARNING:
- SHOULD HFC-134A CONTACT YOUR EYE(S), CONSULT A DOCTOR IMMEDIATELY.
- DO NOT RUB THE AFFECTED EYE(S). INSTEAD, SPLASH QUANTITIES OF FRESH COLD WATER OVER THE AFFECTED AREA TO GRADUALLY RAISE THE TEMPERATURE OF THE REFRIGERANT ABOVE THE FREEZING POINT.
- OBTAIN PROPER MEDICAL TREATMENT AS SOON AS POSSIBLE. SHOULD THE HFC-134A TOUCH THE SKIN, THE INJURY MUST BE TREATED THE SAME AS SKIN WHICH HAS BEEN FROSTBITTEN OR FROZEN.
Refrigerant Recovery
The refrigerant must be discharged and recovered by using the J-39500 (ACR4: HFC-1 34a Refrigerant Recovery/Recycling/Recharging/System) or equivalent before removing or mounting air conditioning parts.
1. Connect the high and low charging hoses of the ACR4 (or equivalent) as shown.
2. Recover the refrigerant by following the Manufacturer's Instructions.
3. When a part is removed, put a cap or a plug on the connecting portion so that dust, dirt or moisture cannot get into it.
Refrigerant Recycling
Recycle the refrigerant recovered by J-39500 (ACR4 :HFC-134a Refrigerant Recovery/Recycling I Recharging/System) or equivalent.
For the details of the actual operation, follow the steps in the ACR4 (or equivalent) Manufacturer's Instructions.
Evacuation of The Refrigerant System
NOTE: Explained below is a method using a vacuum pump. Refer to the ACR4 (or equivalent) manufacturer's instructions when evacuating the system with a ACR4 (or equivalent).
Air and moisture in the refrigerant will cause problems in the air conditioning system. Therefore, before charging the refrigerant, be sure to evacuate air and moisture thoroughly from the system.
1. Connect the gauge manifold.
- High-pressure valve (HI) - Discharge-side.
- Low-pressure valve (LOW) - Suction-side.
2. Discharge and recover the refrigerant.
3. Connect the center hose of the gauge manifold set to the vacuum pump inlet.
4. Operate the vacuum pump, open shut off valve and then open both hand valves.
5. When the low-pressure gauge indicates approximately 750 mmHg (30 inHg), continue the evacuation for 5 minutes or more.
6. Close both hand valves and stop the vacuum pump.
7. Check to ensure that the pressure does not change after 10 minutes or more.
- If the pressure changes, check the system for leaks.
- If leaks occur, retighten the refrigerant line connections and repeat the evacuation steps.
8. If no leaks are found, again operate the vacuum pump for 20 minutes or more. After confirming that the gauge manifold pressure is at 750 mmHg (30 inHg), close both hand valves.
9. Close positive shut off valve. Stop the vacuum pump and disconnect the center hose from the vacuum pump.
Charging The Refrigerant System
There are various methods of charging refrigerant into the air conditioning system.
These include using J-39500 (ACR4 :HFC-134a Refrigerant Recovery/ Recycling/ Recharging/ System) or equivalent and direct charging with a weight scale charging station.
Charging Procedure
- ACR4 (or equivalent) Method
For the charging of refrigerant recovered by ACR4 (or equivalent), follow the manufacturer's instruction.
- Direct charging with a weight scale charging station method
1. Make sure the evacuation process is correctly completed.
2. Connect the center hose of the manifold gauge to the weight scale.
3. Connect the low pressure charging hose of the manifold gauge to the low pressure side service valve of the vehicle.
4. Connect the high pressure charging hose of the manifold gauge to the high pressure side service valve of the vehicle.
5. Place the refrigerant container(3) up right on a weight scale(4).
Note the total weight before charging the refrigerant.
a. Open the refrigerant container valve
b. Open the low side vale on the manifold gauge set. Refer to the manufacturer's instructions for a weight scale charging station.
6. Perform a system leak test:
- Charge the system with approximately 200 g (0.44 lb) of HFC-134a.
- Make sure the high pressure valve of the manifold gauge is closed.
- Check to ensure that the degree of pressure does not change.
Check for refrigerant leaks by using a HFC-1 34a leak detector.
- If a leak occurs, recover the refrigerant. Repair the leak and start all over again from the first step of evacuation.
7. If no leaks are found, continue charging refrigerant to the air conditioning system.
- Charge the refrigerant until the scale reading decreases by the amount of the charge specified.
Specified amount: 600 g (1.32 lb)
- If charging the system becomes difficult:
1. Run the engine at idle and close all the vehicle doors.
2. Turn A/C switch ON.
3. Set the fan switch to its highest position.
4. Set the air source selector lever to CIRC.
5. Slowly open the low side valve on the manifold gauge set.
WARNING: Be absolutely sure not to open the high pressure valve of the manifold gauge. Should the high pressure valve be opened, the high pressure refrigerant would flow backward, and this may cause the refrigerant container to burst.
8. When finished with the refrigerant charging, close the low pressure valve of the manifold gauge and container valve.
9. Check for refrigerant leaks.
Checking The A/C System
1. Run the engine and close all the vehicle doors.
2. Turn A/C switch ON, set the fan switch to its highest position.
3. Set the air source lever to CIRC, set the temperature lever to the full cool position.
4. Check the high and low pressure of the manifold gauge.
- Immediately after charging refrigerant, both high and low pressures might be slightly high, but they settle down to the pressure guidelines shown below:
- The ambient temperature should be between 25 - 30 °C (77 - 86 °F).
- The pressure guideline for the high-pressure side is approximately 1372.9-1863.3 kPa (199.1 - 270.2 psi).
- The pressure guideline for the low-pressure side is approximately 147.1 - 294.2 kPa (21.3 - 42.7 psi).
- If an abnormal pressure is found, refer to Checking The Refrigerant System With Manifold Gauge .
5. Put your hand in front of the air outlet and move the temperature control ever of the control panel to different positions. Check if the outlet temperature changes as selected by the control knob.