[DeTomaso] Air Conditioning Question- Specifically Regarding Replacement of the Expansion Valve... Or Not...

[Chris Difani]

Guys:

One of the tasks still before me is my AC system. I've finally got all the components on hand; new compressor, AN hoses, new condenser, new expansion valve, new drier, and so forth. I've added the "low pressure or high pressure" safety switch on the drier, and have wired that into the AC control system. The last decision to make, before I jump head first into this project, is do I, or do I not, replace the expansion valve. 

Today (which is what's prompted this particular project getting bumped up in the priority pile) I received my flush kit, so I can flush the system's parts (before I do the final assembly and charging). My dilemma is whether to replace the 35 year old expansion valve, or leave it in place. The system has not operated in 6 years, and has been "open to the atmosphere" for most of that 6 years (or at least not charged, and not sealed). 

As far as I know, before the system was disassembled in 2002, it worked. There have been no component failures that would introduce "stuff" into the system internals (like a compressor melt down), or any other kinds of systemic failures. 

My only thoughts on this, pro or con, is that I should replace the expansion valve because: 1) I can; 2) the system's been open for 4 years; 3) it's the hardest option; 4) it's the safest option in terms of AC system dependability; and 5) it's the hardest option.

I guess this comes down to the issue of "just how tough are those expansion valves?". Has everyone that's changed their systems to 134a; or repaired their system after it was "down" for years and years; or bought their car and learned that the AC didn't work; or whatever; did you change the expansion valve as part of the repair process? Or did you leave it alone?

Maybe another way to ask this; did the AC shops change your expansion valve as part of the "get it working" service?, or as part of the "change to 134a" service? Or did they leave it alone?

Thanks, as always, for your help, and opinions,

Chris

Chris Difani
'73 L #5829 "LITNNG"
The Electric Pantera
Sacramento, CA
Email: cdifani at pacbell.net