Question

Explain in your own words the process of removing inspecting and installing a TXV

Thank you in advance!

Answer 1

Removing, Inspecting, and Installing a TXV

A TXV would be removed for inspection if the diagnostic process led to the TXV being stuck open or closed, which would be determined by gauge pressures and air-conditioning performance. If stuck open, the high-side pressures would be low and the low-side pressures would be high. If stuck closed, the high-side pressures would be high and the low-side pressures would be low and could even go into a vacuum.

When working with the expansion valve, caution must be used in all aspects of the removal and installation of the valve. Typically, the TXV is mounted on the front of the evaporator. When removing and installing the inlet and outlet lines to the evaporator, a line wrench must be used so the nuts or bolts are not damaged or rounded off. A second wrench is used to hold the other end of the line so you do not twist it and break it off. One nut will be on the line; the other nut will be on the TXV. Twist the nut on the line and hold the nut on the TXV so as not to deform or break the TXV. A backup wrench on the expansion valve must be used also. The lines from the evaporator are aluminum, and the fittings are typically brass, so the use of an open-ended wrench will distort the brass and cause the fitting to leak. The exact procedure for removing, inspecting, and installing a TXV varies widely from vehicle to vehicle and by TXV manufacturer. Refer to the service information for the precise process.

To remove, inspect, and install a TXV, follow the steps in SKILL DRILL 42-19:

1)After reclaiming the air-conditioning system, use a wrench to loosen the bolt holding the liquid and suction line block to the expansion valve.

2)Remove the center stud going through the expansion valve. Gently remove the lines from the expansion valve.

3)Remove the bolts holding the expansion valve to the evaporator inlet.

4)Install new gaskets or O-rings onto the new expansion valve and the suction and liquid lines.

5)Install the new expansion valve and torque the bolts to specification.

6)Install a new mounting stud. Reinstall the lines to the expansion valve and tighten retaining nut. Evacuate the system if all other repairs were made.