expansion valve?

[BWDart]

How can you tell if the expansion valve is bad?
Thanks Bruce

 

[1969reddart]

With a low pressure side guage attached and A/C on, take the sensing element(top of valve) and warm it with your hand. Pressure should go up. Then, dip the sensing element in ice water. Pressure should go down. This tells you the valve is modulating properly. If the pressure stays low, and the valve does not modulate, the power head could be dead(round disk-top of valve) or it could have a break in the sensing element(release of the internal refrigerant charge), not letting the valve open. If the pressure stays high, and the valve does not modulate, The valve could be stuck open. I've never worked on auto A/C but it all works the same.

 

[BWDart]

Thanks for the info I'll check it in the morning.