Hose/Line HVAC: Service Precautions

Handling of Refrigerant Lines and Fittings


CAUTION: Avoid breathing the A/C Refrigerant 134a (R-134a) and the lubricant vapor or the mist. Exposure may irritate the eyes, nose, and throat. Work in a well ventilated area. In order to remove R-134a from the A/C system, use service equipment that is certified to meet the requirements of SAE J 2210 (R-134a recycling equipment). If an accidental system discharge occurs, ventilate the work area before continuing service. Additional health and safety in formation may be obtained from the refrigerant and lubricant manufacturers.

^ Ensure that the metal lines do not exhibit the following conditions.
This will prevent the loss of system capacity clue to line restriction:
- Dents
- kinks
^ Do not bend the flexible hose line to a radius of less than 4 times the diameter of the hose.
^ Do not allow the flexible hose line to come within a distance of 63.5 mm (2 1/2 in) of the exhaust manifold.
^ Inspect the flexible hose lines regularly. Replace the flexible hose line with new hose If one of the following conditions exist:
- Leaks
- Brittleness
- Deterioration
^ Before disconnecting any fitting in the refrigeration system, recover all of the Refrigerant-134a in refrigerant recovery and recharging.
^ Once you open a refrigerant line to the atmosphere, cap or tape the line immediately. This will prevent any of the following items from entering the line:
- Moisture
- Dint
^ Use the proper wrenches when you make connections on the O-ring fittings. Back-up the opposing fitting with a wrench in order to prevent distortion of the following areas:
- The connecting lines
- The components
^ Tighten all of the tubing connections to the specified torque.
Too much or too little torque may result in the following conditions:
- Loose joints
- Deformed joint parts
- Refrigerant leakage
- An inoperative A/C system
^ Ensure that the flat washer, O-rings and the seats are in perfect condition.
A burr or a piece of dirt may cause a refrigerant leak.
^ Install new flat washer, O-rings that you have lubricated with PAG oil.
Do not wipe the threads with a cloth.
^ Keep PAG synthetic refrigerant oil off fitting threads. Long term contact of PAG synthetic oil on threads may cause future disassembly difficulties. Do not use PAG synthetic oil. Do not wipe threads with a cloth.