10 hours ago, Captain Obvious said:

Nuh uhh.

Sorry, didn't mean the Valve itself.  I was thinking of the attached capillary tube that winds down into the heater box behind the evaporator. Is there another way to access it?

 

1 hour ago, gwri8 said:

Sorry, didn't mean the Valve itself.  I was thinking of the attached capillary tube that winds down into the heater box behind the evaporator. Is there another way to access it?

Oh yeah. So now I'm sorry as well. I forgot about that part.   

I don't know if you can manage to get enough room under the evaporator housing to get that capillary tube out. You jussssst might be able to loosen up the evaporator box and lift it up enough to get the capillary out without evacuating the system. But you're absolutely going to have to pull the dash to even have half a chance. Sorry for the potentially misleading info!

That capillary temp control is a nice feature, but I wouldn't evacuate a working system to replace it. I'd just clip it off and switch over to a non-thermostatically assisted valve.

Here's a relatively thread where we were discussing that little capillary tube and it's involvement in replacing the water control valve.

Lots of good info in there, but this other member already had an empty A/C system, so he didn't have to worry about breaking into it. However, I don't know if he disconnected the lines going to the evaporator or just moved the box out of the way to get behind it:

http://www.classiczcars.com/forums/topic/58410-heater-valve-copper-thermostat-wire-do-i-have-to-remove-the-dash/