Air Conditioning and Heating R-12 All Caterpillar Machines – Refrigerant Orifice Tube – Remove and Install

The orifice tube may be located in the refrigerant line near the evaporator inlet, or in the in-line dryer.

If the orifice tube is located in the refrigerant line near the evaporator inlet use the procedure that follows. If the orifice tube is located in the in-line dryer, refer to Dryer Replacement.

Removing the Orifice Tube

Refer to Safety Requirements before service work is performed on the air conditioning system.

The refrigerant must be recovered before removing the accumulator. Refer to the Service Manual, SENR3334, “Refrigerant Recovery” section in testing and adjusting.


NOTICE

Do not attempt to remove the orifice tube with pliers. Do not twist or rotate the orifice tube in the tube assembly.




Illustration 1 g00379603

Orifice tube

(1) O-Ring seals

(2) Lugs

(3) Body

(4) Drive screw

(5) Finger lock

  1. Disconnect the high side line at the enlarged section of the evaporator inlet port. This will expose the orifice tube for removal.
  1. The short prongs on the 208-1375 Orifice Tool Gp must be aligned with the ribs on the orifice tube. Insert the tool onto the tube until the tool bottoms out.
  1. Turn drive screw (4) clockwise. Turn far enough to engage the lugs (2) on the orifice tube in the finger lock (5). The finger lock (5) is part of the removal tool.
  1. Hold the drive screw (4) stationary. Thread the body (3) forward until the body makes contact with the inlet port.
  1. Continue holding the drive screw stationary, and thread the body forward until the orifice tube becomes free.



    Illustration 2 g00381412

    Removing the broken orifice tube

    (3) Body

    (4) Drive screw

    (6) Extractor tip

  1. In order to remove the orifice tube assembly, use the extractor tip (6) on 208-1375 Orifice Tool Gp. Insert the tool into the evaporator inlet tube and thread the tool into the brass center of the orifice tube.
  1. Repeat steps 3 and 4.
  1. If only the brass center of the orifice tube is removed, thread the tool into the plastic body and repeat step 3 and 4.

Orifice Tube Installation

  1. Lubricate the O-Ring on the orifice tube with the proper clean refrigerant oil.
  1. Place the orifice tube into the 208-1375 Orifice Tool Gp. Insert the orifice tube straight into the evaporator inlet tube without twisting until the tube is seated.
  1. Disengage the removal tool from the orifice tube.
  1. Use a new O-Ring that is lubricated with clean refrigerant oil. Reconnect the high side line at the enlarged section of the evaporator inlet port.
  1. Do a leak test. Evacuate the system and recharge the system. Refer to the Service Manual, SENR3334, “Refrigerant Systems-Evacuate” section in testing and adjusting. Also, refer to the Service Manual, SENR3334, “Refrigerant Systems-Charge” section in testing and adjusting.
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