Usage:
NOTE: Before beginning the following procedure, swing the machine to gain access to the panel mounted beneath the cab on the frame. Removing the panel allows access to disconnect the hoses to the heater and air conditioning unit.
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Effective July 1, 1992 regulations prohibit the venting of any refrigerant into the atmosphere. Refer to Caterpillar publication SENR3334-01, SENR5664 and NEDG5065-01 for the proper procedure, equipment and tools to reclaim refrigerant from any Caterpillar machine. |
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Always wear goggles when working on air conditioning systems. The system is under pressure at all times, engine running or not. Escaping refrigerant R-12 (C C12 F2 Dichloro Difluoro Methane) and refrigerant R-134A can cause freezing of human flesh. Do Not smoke while working on air conditioning. Inhaling Refrigerant R-12 or R-134A through any smoking material, although not toxic or flammable, can cause violent illness. Also heat must never be applied to a charged system. See Air Conditioning And Heating Service Manual Form No. SENR3334-01 and SENR5664, for more information on the removal and the installation of lines and refrigerant from the system. |
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NOTE: Use a refrigerant reclaimer before loosening any lines or bolts.
1. Evacuate the refrigerant in air conditioning system.
2. Close the water shutoff valves located on the water pump.
3. Remove the cab. Refer to the topic "Remove & Install Cab" in this module.
4. Remove six bolts (1).
5. Remove panel (2).
6. Disconnect heater hoses (3) and air conditioning hoses (4).
NOTE: When installing the heater lines, tighten the clamps to a torque of 7.5 ± 0.5 N*m (65 ± 4 lb in).
7. Disconnect main wiring harness disconnect (7).
8. Remove five bolts (6).
9. Remove the heating and air conditioning unit (5).
NOTE: For the installation of the heating and air conditioning unit, reverse the removal steps.
10. Install the cab. Refer to the topic "Remove & Install Cab" in this module.
11. Open the water shutoff valves located on the water pump.
12. Charge the air conditioning system.
Disassemble & Assemble Case (Heating & Air Conditioning Unit)
Front View Of Unit
Side View Of Unit
1. Disconnect three connectors (5).
2. Remove six screws (1).
3. Remove controller cover (2).
4. Remove four screws (3).
5. Remove controller (4).
6. Remove two bolts (8) and the washers.
7. Remove screw (6).
8. Remove piping cover (7).
9. Disconnect connector (11).
10. Remove two screws (9).
11. Remove resistor (10).
| NOTICE |
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Use extra care not to deform coil (12) when removing the resistor. |
12. Open clamp (13) to free one end of releasing valve rod (14).
13. Disconnect connector (15).
14. Remove three screws (16).
15. Remove 11 clamps (17) with a screwdriver.
16. Pull case (18) up.
NOTE: For the installation of the case (heating & air conditioning unit), reverse the removal steps.
Disassemble & Assemble Thermistor (Air Conditioning System)
Start By:
a. remove case (heating and air conditioning unit)
1. Remove grommet (1).
2. Remove bolt (2) and washer.
3. Remove clamps (3) and (4).
4. Pull evaporator (5) upward.
| NOTICE |
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Raise the evaporator using extra care not to damage nearby lines. |
5. Release clip (7).
6. Release thermistor (6) from clip (7).
7. Pull thermistor (6) with grommet (9) out through the hole in case (8).
NOTE: For the installation of the thermistor, reverse the removal steps.
NOTE: When sensor section (10) of thermistor (6) is correctly installed, the thermistor should be below clip (7) as shown in Illustration C45831P1.
End By:
a. install case (heating & air conditioning unit)
Disassemble & Assemble Evaporator & Expansion Valve (Air Conditioning System)
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Effective July 1, 1992 regulations prohibit the venting of any refrigerant into the atmosphere. Refer to Caterpillar publication SENR3334-01, SENR5664 and NEDG5065-01 for the proper procedure, equipment and tools to reclaim refrigerant from any Caterpillar machine. |
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Always wear goggles when working on air conditioning systems. The system is under pressure at all times, engine running or not. Escaping refrigerant R-12 (C C12 F2 Dichloro Difluoro Methane) and refrigerant R-134A can cause freezing of human flesh. Do Not smoke while working on air conditioning. Inhaling Refrigerant R-12 or R-134A through any smoking material, although not toxic or flammable, can cause violent illness. Also heat must never be applied to a charged system. See Air Conditioning And Heating Service Manual Form No. SENR3334-01 and SENR5664, for more information on the removal and the installation of lines and refrigerant from the system. |
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NOTE: Use a refrigerant reclaimer before loosening any lines or bolts.
| NOTICE |
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When installing a new or reworked evaporator use all new O-rings for the installation. Be sure to plug all of the openings of the hydraulic lines and the components removed, to keep the system from becoming contaminated. |
Start By:
a. remove thermistor (air conditioning system)
1. Remove insulator (2).
2. Remove clamp (6).
3. Loosen nuts (4) and (5), and disconnect the lines from evaporator (1).
NOTE: For the installation of the evaporator (air conditioning system), reverse the removal steps.
| NOTICE |
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The following four steps should be checked and deemed satisfactory before proceeding: |
a. Temperature sensing tube (7) should be positioned as shown.
b. Capillary tube (3) should be coiled appropriately to about 508 mm (20 inch) diameter.
c. Install a new heat insulator (2).
d. Make sure new heat insulator (2) is installed correctly on tube (7) to completely insulate it.
e. After installing the upper case, turn clamp (12) in the arrow direction until it stops. Disconnect one end of rod (11) from clamp (12).
NOTE: Do Not disconnect the other end of rod (11) from clamp (10) at this time.
4. Check to make sure that rod (9) turns freely with a minimum of 5 mm (.200 inch) clearance to damper (8).
5. If this is satisfactory, connect rod (11) to rod (9).
End By:
a. install thermistor (air conditioning system)
Disassemble & Assemble Heater Core (Heating System)
Start By:
a. remove case (heating and air conditioning unit)
1. Remove two bolts (5) and the washers.
2. Remove bracket (6).
3. Remove four screws (4).
4. Remove clip (7).
5. Loosen clamp (2).
6. Pull heater core (1) up.
NOTE: For the installation of the heater core, reverse the removal steps.
NOTE: Use a new heater hose (3) when installing the heater core.
End by:
a. install case (heating and air conditioning unit)
Disassemble & Assemble Motor (Air Conditioning System)
NOTE: The motor controls the vent that allows circulated air to enter the cab.
1. Open clamp (7) to free one end of rod (8).
2. Disconnect connector (1).
3. Remove four screws (3).
4. Remove motor (2).
NOTE: The following steps are for the installation of the motor (air conditioning system).
5. Position motor (2).
6. Install four screws (3).
7. Connect connector (1).
8. Turn rod (4) in the arrow direction until it stops.
9. Insert one end of rod (8) into clamp (5).
10. Hold the other end of rod (8) with clamp (7).
| NOTICE |
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Open clamp (7) to free one end of rod (8) only when absolutely necessary. If separated, lever (6) should be placed in the position shown on C45836P1. |
11. If the lever is not in the position shown, do the following steps:
a. Turn the air conditioning switch "ON", and place the air outlet selection switch in the air-circulation mode position. Wait for ten seconds until lever (6) returns to the correct position as shown in Illustration C45836P1.
b. Turn the switch "OFF", and hold rod (8) in place using the procedure described in Steps 8 and 9.
Disassemble & Assemble Motor (Heating System)
NOTE: The motor opens and shuts the water valve that controls water entering the heater core.
1. Remove four bolts that hold the cover to the evaporator and heater core case.
2. Open clamp (6) to free one end of rod (5).
3. Disconnect connector (9).
4. Remove four screws (4) to remove motor (2).
NOTE: The following steps are for the installation of the motor (heating system).
5. Position motor (2).
6. Install four screws (4).
7. Connect connector (9).
8. Hold the free end of the rod (5) with clamp (3), with spring (7) and washer (8) tensioned slightly 1 mm (.039 inch).
| NOTICE |
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The other end of rod (5) should be separated from clamp (3) only when absolutely necessary. If separated, lever (1) should be placed in the position shown in Illustration C45850P2. If not in the position, do the following procedure: |
a. Turn the air conditioner switch "ON". Both minimum level LEDs of heating and cooling will come on. Wait for 10 seconds until lever (1) returns to the correct position, as shown in Illustration C45850P2.
b. Turn the switch "OFF", and connect rod (5) using the procedure described in Step 8.
Disassemble & Assemble Water Valve (Heating System)
NOTE: The water valve which is controlled by a motor permits water to enter the heater core.
1. Remove four bolts that hold the cover to the evaporator and heater core case.
2. Turn the air conditioner switch "ON". Both minimum level LEDs of heating and cooling will come on. Wait for 10 seconds until lever (1) returns to the correct position as shown in Illustration C45850P3.
3. Turn the air conditioning switch "Off".
4. Open clamp (2) to free the lower end of rod (3).
5. Remove screw (9) to remove clip (8).
6. Remove three screws (9) to remove the bracket.
7. Loosen two clamps (7) to disconnect hose (6).
8. Remove two bolts (10) if required.
9. Remove valve (11).
NOTE: For the installation of the water valve (heating system), reverse the removal steps.
NOTE: During the installation of the water valve, do the following:
a. Correctly position spring (4) and washer (5).
b. Use a new hose (6).
Disassemble & Assemble Dumper Assembly Motors (Heating System)
NOTE: The procedure for removing both dumper assembly motors is the same. The procedure that follows is for one of them.
The dumper assembly motors open and close the vents that allow air to be directed to either the "FOOT" or to the "DEF".
1. Open clamp (3) to free one end of rod (2).
2. Disconnect connector (7).
3. Remove four screws (5).
4. Remove motor (6).
NOTE: The following steps are for the installation of the dumper assembly motor (heating system).
5. Position motor (6).
6. Connect connector (7).
7. Turn rod (1) in the arrow direction until it stops.
8. Move lever (4) of motor (6) in the arrow direction until one end of the rod (2) is in alignment with clamp (3).
| NOTICE |
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The end of rod (2) should be separated from clamp (3) only when absolutely necessary. If separated, lever (4) should be placed in the position shown in Illustration C45839P1. If not in the indicated position, do the following procedure: |
a. Turn the air conditioning switch "ON". Place the air outlet selection switch in the "FOOT" or "DEF" mode position. Wait for ten seconds until lever (4) returns to the correct position as shown in Illustration C45839P1.
b. Turn the air conditioner switch "OFF". Hold rod (2) in place using the procedure described in Steps 7 and 8.
Disassemble & Assemble Blower Motor (Heating & Air Conditioning System
1. Disconnect coupler (1).
2. Remove three bolts (3) and the washers.
3. Remove motor blower (2).
NOTE: For the assembly of the blower motor (heating & air conditioning system), reverse the removal steps.
| NOTICE |
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Use care not to leave foreign substances in cases (5) and (6). A small substance left in the case could cause damage to fan (4). |