TUBE AS 3740039 - Caterpillar

Always wear goggles when working on air conditioning systems. The system is under pressure at all times, engine running or not. Escaping Freon-12 (C C12 F2 Dichloro Difluoro Methane) can cause freezing of human flesh.Do not smoke while working on air conditioning systems. Inhaling Freon-12 through any smoking material, although not toxic or flammable, can generate phosgene gas and cause violent illness. Also, heat must never be applied to a charged system. See Air Conditioning And Heating Service Manual, Form No. SENR7454, for more information on removal and installation of lines and refrigerant from the system.
1. Purge the system only for removal of the air conditioning expansion valve. Disconnect the air conditioning lines behind the cab if any air conditioning components are to be removed to prevent excess loss of Freon. 1. Remove the blower speed resistor as follows:a. Disconnect three wires (1) from resistor (4).b. Remove locknut (2), and slide out rod (3) that holds the resistor in the bracket. Remove resistor (4) and the washers from the bracket.c. Remove the two insulators from resistor (4). 3. Remove the air conditioning expansion valve as follows:a. Remove bolt (8) from clips (7) that hold the tubes in place.b. Disconnect four tube assemblies (5) from expansion valve (6). Remove expansion valve (6) from the machine. 4. Remove the temperature control switch as follows:a. Remove capillary tube (12) from the evaporator coil and the cover plate.b. Disconnect two wires (10) from switch (11).c. Remove two screws (9) and temperature control switch (11). 5. Remove the heater control valve as follows:a. Close the water valves on the heater hoses. The location of one heater valve is in the adapter on the right side of the timing gear cover for the engine oil cooler. The location of the other water valve is on the right side of the engine above the transmission oil cooler.b. Remove bolt (15) that holds the clip to bracket (16).c. Loosen setscrew (17), and remove lever assembly (14) from valve (18).d. Disconnect tubes (13) and (19) from valve (18). e. Remove two bolts (20). Remove bracket (16) and valve (18) as a unit. f. Remove two screws (21) that hold the valve to the bracket. Remove valve (18) from bracket (16).Install Air Conditioning And Heater Components
1. Install the heater control valve as follows:a. Put valve (2) in position on bracket (1), and install the two screws that hold it in place.b. Put valve (2) and bracket (1) in position as a unit, and install the two bolts that hold them in place. c. Connect tubes (3) and (9) to valve (8).d. Put lever assembly (4) in position on the shaft of valve (8) with setscrew (7) aligned with the flat on the shaft. Tighten setscrew (7) to hold the lever assembly in place.e. Put the clip in position on bracket (6), and install bolt (5) that holds it in place.f. Open the water valves on the heater hoses. 2. Install the temperature control switch as follows:a. Put temperature