Heating and Air Conditioning: Service and Repair
Operation Procedure for Refrigerant Charge
WARNING:
- Contact of liquid HFC-134a (R-134a) refrigerant with skin and eyes will cause frostbite. The refrigerant cools the surface coming in contact with it to a temperature much lower than the freezing point of water.
Avoid contact with HFC-134a (R-134a) refrigerant and wear goggles and gloves whenever handling the refrigerant. Should the refrigerant happen to contact your eyes or skin, immediately take action as described below to prevent aggravating the condition:
- In the event of eye contact, do not rub the eye you're your hand. Instead, pour fresh cold water over the eye to gradually raise the temperature. After washing the eye thoroughly with water, receive medical attention as soon as possible.
- If liquid HFC-134a (R-134a) contacts your skin, wash the affected area thoroughly with water. Since the skin may have been frostbitten, receive medical attention.
- If HFC-134a (R-134a) is exposed to high temperatures, it turns into a poisonous gas.
Be sure to take the following precautions to prevent health problems caused by HFC-134a (R-134a) gas.
- Do not handle refrigerant in or near any area where welding or steam cleaning is performed.
- Keep refrigerant in a cold and dark place. Avoid storing it under direct sunlight, in a place close to fire or inside a vehicle.
- If HFC-134a (R-134a) is burned, avoid breathing fumes.
Recovery
When discharging refrigerant out of A/C system, always recover it by using refrigerant recovery and recycling equipment because discharging refrigerant HFC-134a (R-134a) into atmosphere would cause adverse effect to environments.
NOTE:
- After recovering refrigerant from system, the amount of removed compressor oil must be measured for replenishing compressor oil.
- When handling recovery and recycling equipment, be sure to follow the instruction manual for the equipment.
Replenishing Compressor Oil
It is necessary to replenish specified amount of compressor oil to compressor from compressor suction side hole (1) before evacuating and charging refrigerant.
When charging refrigerant only
When charging refrigerant without replacing any component, replenish the same amount of measured oil when recovering refrigerant (if not measure, replenish 10 cm3 (10 ml, 0.34 US.oz, 0.35 Imp.oz) oil).
When replacing compressor
NOTE:
Use of a compressor oil other than the specified oil is inappropriate for the components of the A/C system and may cause problems with operation of the system.
Use only the specified compressor oil or equivalent.
Compressor oil is sealed in each new compressor by the amount required for A/C system. Therefore, when using a new compressor, drain the calculated amount of oil from it.
"C" = "A" - "B"
"C": Amount of oil to be drained
"A": Amount of oil in a new compressor
"B": Amount of oil in removed compressor
NOTE:
Compressor assembly supplied from factory is filled up with the following amount of oil.
Compressor oil: 99000-99022-00E (Compressor oil (DH-PS, 250cc))
Oil amount in compressor
80 - 100 cm3 (80 - 100 ml, 2.71 - 3.38 US.oz, 2.82 - 3.52 Imp.oz)
When replacing other parts
Replenish the following amount of oil to compressor.
Amount of compressor oil to be replenished
Evaporator: 15 cm3 (15 ml, 0.51 US.oz, 0.53 Imp.oz)
Condenser: 10 cm3 (10 ml, 0.34 US.oz, 0.35 Imp.oz)
Dryer: 10 cm3 (10 ml, 0.34 US.oz, 0.35 Imp.oz)
Hoses: 5 cm3 (5 ml, 0.17 US.oz, 0.18 Imp.oz) each
Pipes: 5 cm3 (5 ml, 0.17 US.oz, 0.18 Imp.oz) each
Evacuation
NOTE:
Attempting to evacuate the A/C system when refrigerant remains in the system will damage the vacuum pump.
Do not evacuate the A/C system before completely recovering the refrigerant from the system.
NOTE:
Once air conditioning system circuit is opened (exposed) to atmospheric air, system must be evacuated by using a vacuum pump. The A/C system should be attached with a manifold gauge set, and should be evacuated for approximately 15 minutes.
1) Connect high charging hose (1) and low charging hose (2) of manifold gauge set (3) (special tool) respectively as follows:
High charging hose -> High pressure charging valve (4) on discharge hose
Low charging hose -> Low pressure charging valve (5) on suction pipe
Special Tool
(A): 09990-06020
2) Attach center charging hose (6) of manifold gauge set to vacuum pump (7).
3) Operate vacuum pump, and then open discharge side valve (Hi) (8) of manifold gauge set.
If there is no blockage in the system, there will be an indication on high pressure gauge (9).
When this occurs, open the other side valve (Lo) (10) of the set.
4) Approximately 10 minutes later, low pressure gauge (11) should show a vacuum lower than -100 kPa (-1.0 kgf/cm2, -760 mmHg, -14.7 psi) providing no leakage exists.
NOTE:
- If the system does not show a vacuum below -100 kPa (-1.0 kgf/cm2, -760 mmHg, -14.7 psi), close both valves, stop vacuum pump and watch movement of low pressure gauge.
- Increase in the gauge reading suggests existence of leakage. In this case, repair the system before continuing its evacuation.
- If the gauge shows a stable reading (suggesting no leakage), continue evacuation.
5) Evacuation should be carried out for a total of at least 15 minutes.
6) Continue evacuation until low pressure gauge indicates a vacuum less than -100 kPa (-1.0 kgf/cm2, -760 mmHg, -14.7 psi), and then close both valves.
7) Stop vacuum pump. Disconnect center charging hose from pump inlet. Now, the system is ready for charging refrigerant.
Checking A/C System for Pressure Leaks
After completing the evacuation, close manifold gauge high pressure valve and low pressure valve and wait 10 minutes. Verify that low pressure gauge reading has not changed.
NOTE:
If the gauge reading moves closer to "0", there is a leak somewhere. Inspect the tubing connections and make necessary corrections. And then, evacuate system once again and make sure that there are no leaks.
Charge
WARNING:
There is a risk of personal injury or health problems if the A/C system is charged with refrigerant incorrectly or if refrigerant containers are improperly handled.
Be sure to take the following precautions to reduce the risk of injury or health problems.
- Be sure to perform the refrigerant charge operation with the engine stopped. Charge the high-pressure side first and then the low-pressure side. If you do not, the refrigerant may flow backward and cause the hose or refrigerant container to burst.
- Install the tap valve carefully following the instructions on the refrigerant container to prevent contact with the refrigerant.
- Be sure to empty the refrigerant container before discarding it to prevent possible health problems and other dangerous consequences.
- Never expose the refrigerant container to a heat higher than 40 °C (104 °F). Liquid refrigerant will turn into a toxic gas.
NOTE:
Failure to take proper precautions when charging the A/C system can result in charging the system with the incorrect amount of refrigerant and can lead to poor system operation or damage to system components.
- Since the A/C system has no sight glass, first recover refrigerant and evacuate the system, and then fill the system with the specified amount of refrigerant.
- Charge the system only when the compressor is not hot to assure that you have used the correct amount of refrigerant.
- Be sure to check the pressure gauges before and during charging to assure that there is the correct amount of refrigerant in the system.
- Do not turn the refrigerant container upside down during charging. Doing so will cause liquid refrigerant to enter the compressor and damage it.
NOTE:
The air conditioning system contains HFC-134a (R-134a).
Described here is a method to charge the air conditioning system with refrigerant from the refrigerant service container.
When charging refrigerant recovered by using the refrigerant and recycling equipment (when recycling refrigerant), follow the procedure described in the equipment manufacturer's instruction manual.
The initial charge of the A/C system is performed through the high pressure side with the engine stopped.
And next, this method must be followed by charging from the low pressure side with the engine running.
1) Check if hoses are routed properly after evacuating the system.
2) Connect low charging hose (1) and high charging hose (2) of the manifold gauge set (3) in position. Then, open refrigerant container valve (4) to purge the charging line.
3) Open the high pressure side valve (5) and charge refrigerant to system.
4) After a while, open the low pressure side valve (6) and close the high pressure side valve.
WARNING:
If the high-pressure side valve is not closed securely, the refrigerant may flow backwards and cause the hose or refrigerant container to burst, possibly resulting in a personal injury.
Be sure to close the high-pressure side valve securely.
5) Start engine and keep engine speed at 1500 r/min, and then operate A/C system.
6) Charge A/C system with refrigerant in vapor state. At this time, refrigerant container should be held upright.
7) When refrigerant container (1) is emptied, use the following procedure to replace it with a new refrigerant container.
a) Close low pressure valve.
b) Replace empty container with a refrigerant container which has been charged with refrigerant. When using refrigerant container tap valve (2), use the following procedure for replacement.
i) Retract needle (3) and remove refrigerant container tap valve by loosening its plate nut (4).
ii) Install the refrigerant container tap valve to a new refrigerant container.
c) Purge any air existing in center charging hose.
When using refrigerant container tap valve, use the following procedure to purge air.
i) Once fully tighten refrigerant container tap valve (1), and then loosen (open) plate nut (2) slightly.
ii) Open low pressure side valve (3) of manifold gauge set (4) a little.
iii) As soon as refrigerant comes out with a "hiss" through a clearance between refrigerant container and tap valve, tighten plate nut as well as low pressure side valve.
iv) Turn handle of tap valve clockwise so that its needle is screwed into the new container to make a hole for refrigerant flow.
8) After the system has been charged with specified amount of refrigerant or when low pressure gauge (1) and high pressure gauge (2) have indicated the following specified value, close low pressure side valve (3) on manifold gauge set (4).
Specified amount of refrigerant
430 ± 20 g (15.2 ± 0.7 oz))
Low side and high side pressure example (CVT model)
Low side and high side pressure example (M/T model)
Removal of Manifold Gauge Set
WARNING:
If the manifold gauge set is removed carelessly, refrigerant under pressure may spray out of the high-pressure side of the A/C system. The refrigerant could contact your eyes or skin, causing injury.
Remove the manifold gauge set carefully, following the instructions provided below.
For the A/C system charged with the specified amount of refrigerant, remove manifold gauge set as follows:
1) Close low pressure side valve of manifold gauge set. (The high pressure side valve is closed continuously during the process of charging.)
2) Close refrigerant container valve.
3) Stop engine.
4) Using shop rag, remove charging hoses from service valves. This operation must be performed quickly.
5) Put caps on service valves.
Check A/C System for Refrigerant Leaks
Whenever a refrigerant leak is suspected in the system or any service operation has been performed which may result in malfunction of lines and connections, it is advisable to check for leaks.
Common sense should be used during refrigerant leak test, since the need and extent of any such test will, in general, depend upon the nature of a complaint and the type of a service performed on the system.
Liquid leak detector
WARNING:
If the refrigerant is exposed to a fire, it turns to a poisonous gas (phosgene).
Do not inhale the gas that is produced if refrigerant is exposed to a fire.
There is a number of fittings and places throughout the A/C system where a liquid leak detector solution may be used to pinpoint refrigerant leaks.
By merely applying the solution to the area in question with a swab, such as attached to the cap of a vial, bubbles will form within seconds if there is a leak.
For confined areas, such as sections of the evaporator and condenser, an electronic (refrigerant) leak detector is more practical for determining leaks.
Special Tool
(A): 09990-86012
