Parts needed for A/C installation
I've never seen but 2 issues with the old expansion valves. One, its capillary tube gets a hole in it or kinked closed in handling, then its nitrogen charge is blocked or leaks away. That calls for replacement.
Two, The screen at inlet side gets clogged. I've found as many as 5 of those little cone shaped screens in one valve. Pic them out, clean and reinstall.