So I’ve gotten a few questions regarding the AC Compressor System Expansion Valve and how to repair it.

All ac systems have to have a place to release excess pressure. Many air conditioning compressor systems use an expansion device to release pressure in the atmosphere. This can either be an expansion valve or an expansion block, see picture for more on the difference. They are just different designs of the same. The valve has an external sensor arm while the block is pressure based.

So how to you repair an expansion valve? The answer is to buy a new one. You can clean it out and blow some air through it, but with prices of only $30-$60 for a new one, its just not worth the risk. Most expanison valves are mounted on the ac evaporator, which is inside the firewall. Replacing it can be 3-8 hours of labor because you may have to disassemble the whole dash. Whether you are paying someone for that or doing it yourself it is just not worth it. Buy a new one from a trusted source.