ENGINE AR-CORE 3116137 - Caterpillar

Note: If the refrigerant circuit contains no refrigerant, always evacuate the system before you charge the system. Also, be sure to charge the system by weight.
Illustration 3 g00470339
(1) Low-pressure valve (2) High-pressure valve (3) Low-pressure hose (4) High-pressure hose (5) Service valve (low-pressure side) (6) Charging hose (8) Service valve (high-pressure side) (9) Manifold gauge set (10) Valve on top of refrigerant tank (11) Refrigerant tank (12) Butterfly valve (18) ScaleThis procedure is NOT the preferred procedure, but this procedure may be required under the following conditions:
The tank pressure is too low.
The ambient temperature is too low and a heater blanket is not available to warm the system.Use a scale in order to measure the amount of refrigerant that is charged. Do not use pressure in order to measure the amount of refrigerant that is charged.Refer to Illustration 3 for the following steps.
Connect the manifold gauge set to the discharge and service ports on the compressor. Refer to Testing and Adjusting, "Manifold Gauge Set (Refrigerant) - Install" for the proper procedure.
Make sure that high-pressure valve (2) and low-pressure valve (1) of manifold gauge set (9) are closed.
Purge any air that may remain in the lines by loosening charging hose (6) at the manifold gauge set. Tighten charging hose (6) after 2 to 3 seconds.
Set the machine to the following conditions:
Start the engine and open the door.
Turn on/off switch ON.
Set the temperature select switch to MAX COOL.
Set the fan speed switch to HI.
Increase engine speed to 1500 to 1600 rpm.
Open low-pressure valve (1) of manifold gauge set (9). Also open valve (10) that is located on top of refrigerant tank (11). Low-pressure hose (3) connects to service valve (5) on the suction side of the compressor. Note the readings on the manifold gauge set. The gauge readings should not exceed the normal operating ranges during this procedure.
Slowly add refrigerant until the inlet of the receiver-dryer is cool and the outlet of the receiver-dryer is cool. The temperature of the discharged air should drop during this procedure. When the air temperature drops adequately, close low-pressure valve (1) and allow the system to stabilize for 5 minutes. Proceed to step 7.Note: If the low-pressure valve (1) is opened completely, the low-pressure gauge reading will appear excessively high until the system becomes fully charged.Note: If the suction and discharge pressures become too high, indications of an overcharge are present. Proceed to step 9 if an overcharge occurs.
The system is charged. Close low-pressure valve (1) on the manifold gauge set and close valve (10) on refrigerant tank (11) .
Stop the engine and remove the manifold gauge set. This procedure is complete.
Close valve (10) on the refrigerant tank and shut down the engine.
Recover the refrigerant charge and evacuate the system.
Charge the system. Refer to"Charging the System from the High Pressure Side".Note: Avoid system overcharge. System overcharge causes a sudden rise of high pressure and deterioration of the refrigerant. Overcharging can cause the entire system to operate poorly. Therefore, charge the proper amount of refrigerant.Note: When