Operation CHARM: Car repair manuals for everyone.

Handling of Refrigerant Lines and Fittings

Pipe And Hose Connections Torque:






All metal tubing lines should be free of dents or kinks to prevent loss of system capacity due to line restriction.

- The flexible hose lines should never be bent to a radius of less than four (4) times the diameter of the hose.

- The flexible hose lines should never be allowed to come within a distance of 63.5 mm (2-1/2 inches) of the exhaust manifold.

- Flexible hose lines should be inspected regularly for leaks or brittleness and replaced with new lines if deterioration or leaking is found.

- When disconnecting any fitting in the refrigerant System, the system must be discharged of all Refrigerant-12. However, proceed very cautiously, regardless of the gage readings. Open very slowly, keeping your face and hands away so that no injury can occur. If pressure is noticed when a fitting is loosened, allow it to bleed off very slowly.

- If any refrigerant line is opened to the atmosphere, it should be immediately capped to prevent the entrance of moisture and dirt, which can cause internal compressor wear or plugged lines, in the condenser and evaporator core and expansion (orifice) tubes or compressor inlet screens.

- The use of the proper wrenches when making connections on O-ring fittings, is important. The use of improper wrenches may damage the connection. The opposing fitting should always be backed up with a wrench to prevent distortion of connecting lines or components. When connecting the flexible hose connections, it is important that the swaged fitting and the flare nut. as well as the coupling to which it is attached, be held at the same time using three different wrenches to prevent turning the fitting and damaging the seat.

- The O-rings and seats must be in perfect condition. The slightest burr or piece or piece of dirt may cause a leak. When replacing the O-ring, first dip it in clean 525 viscosity refrigeration oil.


- Tighten tubing connections to the specified torque, refer to accompanying figure.