New to HVAC systems

[Boydsdodge]

Hello, I am pretty green when it comes to AC systems. Heat, no problem. I was just looking at parts I might order for my AC resurrection on the Tux/73 Imperial, when I see that there is a front and rear expansion valve.
If anyone has some input on this, that would be great.
Are there two expansion valves on an Imperial with Autotemp?

 

[CBODY67]

I suspect the "rear" exp valve would only be there if there was a rear seat a/c system in addition to the front a/c system.

 

[JMC85284]

For comparison, here’s my 73 Imperial with a single expansion valve - no rear AC system. The liquid line is removed because I’m also in the middle of trying to resurrect the ATC II system.

Also for what it’s worth - I had a hell of a time getting the EV off. Used about half a can of PB blaster in repeated shots over a couple days, no dice. Finally tried a different spray called Knocker Loose and maybe it was happenstance but it came right off about 5 minutes after first spray albeit with a lot of groaning. Used 2 wrenches and was careful not to torque the firewall connection.

 

[JMC85284]

To clarify - you DO want to torque the fitting SLEEVE coming from the firewall connection (ie, you want to turn the sleeve rather than trying to just turning the expansion valve that fits into the sleeve) but not twist/bend the pipe. I've heard that you need to be extra careful with EV removal because messing up that connection/pipe is a good way to wreck your evaporator.