Automotive Air Conditioning Information Forum (Archives)

PANTERA2511 on Mon July 27, 2015 5:06 PM

Year: 1972
Make: DeTomaso
Model: Pantera
Engine Size: 351
Refrigerant Type: R12

Recently ordered, from a Pantera vendor, an R12 replacement expansion valve. What arrived was a #6 & #8 flare fiting valve, clearly marked 134a. Upon contacting the vendor, he told me that it was correct because it had flare fittings, and the Pantera used a flare fitting valve. I returned it.

That just didn't sound right to me, and this vendor is far from infallible, so I'm coming to this Forum for your collective knowledge and wisdom.

First I have never been able to cross-reference the original Pantera/Ford part number for the valve to anything current.

That number was D16Y 19849-A. Perhaps one of you can provide a current part number?

I previously collected what I was told was the proper generic/aftermarket replacement, and it is a Four Seasons 38608.

It doesn't seem reasonable that all Ford early 70s expansion valves are interchangeable? But it now seems that most of the 70's Ford valves listed on eBay often share the same number for a LOT of vehicles.

So, will any Ford R12 early 70s era valve work in the Pantera? If it isn't the perfect match to the original Ford Pantera unit, will the design differences result in any noticeable loss of cooling or other system issues?

And would that 134a valve actually work? As well as the original? As well as a close 70s era unit?

In short, what do you suggest for a Pantera still retaining R12 and wanting to replace the expansion valve?

Finally, I and many owners have upgraded to Sanden rotary units, increased depth tube and fin condensers or newer single and double stacked parallel flow units, and new evaporators with fewer coolant tubes and added Freon tubes. I don't think any of those modifications should affect the R12 expansion valve choice, but thought it should be mentioned, just in case.

This is something that has bugged me for many years, and I've yet to come across anyone in the Pantera community that seems to have a full and clear grasp of the issue.

Bueller? Anyone?

Thanks!!

Larry

jsmitty on Tue July 28, 2015 8:27 AM

In my experience expansion valves never really cared much about what refrigerant was used. They are far superior than just an orifice, since it's size varies based on evaporator temperature.

I've had an expansion valve system blow air so cold it fogged the rear glass in a truck I owned, using bbq propane as a refrigerant - not ideal by any stretch, and probably not legal, but it worked amazingly. Same stuff in an orifice tube system had stratospherically high head pressures with little to no cooling. The expansion valve will open or close based on evap temps, so you always have the perfect cooling no matter the situation. Plus, there's no bang-on, bang-off cycling that you have with a orifice tube system.

Anyway, I don't think refrigerant type is going to make any difference with that expansion valve. Someone will correct me if I'm wrong ...

mk378 on Tue July 28, 2015 8:33 AM

They do care, but R-12 and 134a are similar enough at evaporator pressures and temperatures that it will work. The old R-12 valves were actually filled with R-12 in the sensor bulb, since R-12 is not allowed in new manufacture there really aren't any true R-12 valves on the market any more. But the R-134a valves will give nearly identical performance with R-12.