So, a couple of things:

Refrigerant?  Did you convert to R-134A, or still R-12?  200 psig is not necessarily high depending on the ambient temp.  But 200 high side with 0 on the low certainly sounds like restriction.

You replaced the Receiver/Drier right?  If not, that's a likely place for the restriction to be, and should be replaced whenever the system is opened, and certainly when it's been opened for a long while.

If the drier was replaced, then the expansion valve is probably the problem - but, I would also check through the system to make sure no one added an inline filter that may have clogged, especially if it was in the line when you flushed.

Keith Hughes
'86 Westy Tiico (Marvin)

 ------------------------------
 
 Date:� � Sun, 5 Jul 2015 23:38:36 -0400
 From:� � Michael McSwain <michaelmcswain@GMAIL.COM>
 Subject: My A/C Saga Continues...
 
 So So close, but no cigar.
 
 Wanted to see if my theory sounds reasonable to anyone who
 knows more about
 this than me.
 
 So I finally got this old Behr system put together
 today.� I flushed the
 system, sprayed compressed air through to get as much of the
 flush out or
 evaporated, put it on a vacuum and let it sit for 3+ hours
 until I was
 convinced there were no leaks, and finally began charging
 the system.
 
 Because of some rust and a previous owners trigger happy
 spray painting I
 was advised by a friend to leave some of the o-rings be, but
 I did replace
 them at the compressor and dryer.
 
 Our disappointing results were as follows:
 
 Too much pressure on the high side, a little over 200 while
 running.
 
 Too little pressure on the low side. Pegged at zero while
 running.� One
 part that I didn't replace, (kicking myself now because
 several people
 mentioned that I should, including some on this list), was
 the expansion
 valve.
 
 So the theory is that if the expansion valve was plugged or
 gunked up, the
 compressor would eventually suck all of the refrigerant out
 of the low side
 and pump it into the high side and with no way to flow
 through the system
 and back to the low side I ended up with too much pressure
 on one side and
 a vacuum on the other.
 
 I'm thinking that a clogged expansion valve be the most
 likely culprit.
 
 I'm new to this, but does that sound about right?