How to test an Expansion Valve

One of our viewers asked, how do you test an expansion valve? Welcome to Mercie J auto care, where compassion and craftsmanship come together. I’m Rick Smith, master certified technician. What an expansion valve does is it actually controls the flow of refrigerant through the evaporator. This is the part that’s inside your dash so you can’t see it, the only real way to test an expansion valve is with pressure gauges. You take a look at the pressures and usually if they get restricted, then the pressure on the low side will drop really low. Other than that there’s not really a lot you can do that’s easy to test without professional automotive equipment. One little note, if the system is not evacuated properly and there’s any moisture in the system then as this expansion valve drops the air conditioning pressure and it drops the temperature, it can actually get a little droplet of ice and plug it up. So sometimes it could be a bad expensive valve but it also may not have been evacuated properly. So that is why it is important to have a trusted auto repair professional. I hope this is informational to you and until next time, safe travels and blessings to you.