Refrigerant guages

[DD T/A]

I work on old cars at home and have always been interested in doing my own A/C work; specifically, work involving R12 refrigerant(let's not make this a R12 vs R134a debate please).

I was at the swap this morning and on a whim bought this manifold for $25. It looks like I should have a couple valves on the side that aren't there. What did I buy?


Can you tell me what I am missing, and if it was worth the money? Can it be used/retrofitted for R12 use?
It seems to be somewhat easy to source R12 in small hand-held cans on craigslist, could this manifold be used with them?


Thanks for the time everyone.

 

[gungatim]

anything snap-on for $25 is usually worth it. it looks like it is for R12 already. you use the threaded cans. the hoses unscrew from the sides. likely you can find a parts list or instructions if you can find the part #

 

[DD T/A]

That is the odd thing, there appears to be no par number stamped, but there is a very faded piece of paper on the back of one of the gauges. I'll see if I can't figure out what is says.

Thank you for the reply.

 

[AA/FC]

Those gauges are not missing anything. And as mentioned, will already work with R-12 just the way they sit with no other modification. Those hoses should screw right onto 1/4" flare fitting.... which is what R-12 and R-22 used for service ports.

Also... nothing to debte about R-12 vs R-134a. Everyone knows that R-12 was a much better, and more efficient refrigerant than R-134a. And as it turns out, it wasnt really as bad for the environment as the government wanted you to believe. It all came down to money and expiring patents that led to its demise. Bottom line.... R-12 is still legal to possess and use in the US... it's just not legal to produce or import into the country. Technically, you need an EPA sec. 609 aumotive technician license to buy (and use) R-12 but if you're getting it off craigslist then I doubt the private seller is checking credentials.


Once modern vehicles had their A/C components "sized" properly to work with R-134a the end result was the same.... nice cold air. Those first few years of 134 were tough when vehicles were basically still being built with components designed to work with 12. Those days are long gone though..... and now we're onto our next version of automotive refrigerant, R1234yf.

 

[DD T/A]

Those gauges are not missing anything. And as mentioned, will already work with R-12 just the way they sit with no other modification. Those hoses should screw right onto 1/4" flare fitting.... which is what R-12 and R-22 used for service ports.

Also... nothing to debte about R-12 vs R-134a. Everyone knows that R-12 was a much better, and more efficient refrigerant than R-134a. And as it turns out, it wasnt really as bad for the environment as the government wanted you to believe. It all came down to money and expiring patents that led to its demise. Bottom line.... R-12 is still legal to possess and use in the US... it's just not legal to produce or import into the country. Technically, you need an EPA sec. 609 aumotive technician license to buy (and use) R-12 but if you're getting it off craigslist then I doubt the private seller is checking credentials.


Once modern vehicles had their A/C components "sized" properly to work with R-134a the end result was the same.... nice cold air. Those first few years of 134 were tough when vehicles were basically still being built with components designed to work with 12. Those days are long gone though..... and now we're onto our next version of automotive refrigerant, R1234yf.

Thank you for the info. Your statements about R12 are basically what got me out of the "convert my old cars to R134" mindset. I'm not going to go through more effort to downgrade my A/C.


Question:

My uncle works for a local utility and has a couple years old diesel Ford F450 bucket truck, and sitting still at idle the A/C was freezing me into the ice age. My 20 year old R134 style Honda can't do that at highway speeds.


Is it reasonable to get that kind of "freezing even sitting still at idle" out of let's say a 1970 Chevy using R12?

 

[AA/FC]

Is it reasonable to get that kind of "freezing even sitting still at idle" out of let's say a 1970 Chevy using R12?

Sure, that's what old R-12 systems were known for.... as long as the system was functioning properly.

 

[DD T/A]

When I come across that part of my project, would you object to me asking you(through PM) some questions about that era of R12 systems? (I'm working on a 1971 Camaro with POA style A/C )

 

[AA/FC]

When I come across that part of my project, would you object to me asking you(through PM) some questions about that era of R12 systems? (I'm working on a 1971 Camaro with POA style A/C )

No problem.

 

[AA/FC]

Also, there are a few automotive related A/C forums on the internet that are really good. I'm not sure if I can post links to other forums, but do a google search and I'm sure you'll find what I'm talking about. Those guys are always willing to help strangers with little or no A/C knowledge.

 

[Schurkey]

The older systems had adjustable expansion valves that could be set for 32--33 degrees--just warm enough that the evaporator wouldn't freeze. They'd blow tiny ice crystals out the vents.

The later orifice-tube expansion systems are neither adjustable nor particularly cold. 40 degrees is about as good as it gets, and sometimes 45 degrees is all you can have. Fuel efficiency and cost-cutting are the priorities, not passenger comfort.

I've heard--but never actually researched--that GM applications can use a Ford orifice tube that is a bit larger for more refrigerant flow. This, in turn, lowers the air temperature.

 

[gungatim]

yeah the ford orifice is a common thing to use. actually they are color coded IIRC, for different sizing but people call it the Ford tube. very common to use when updating older systems. the other popular thing to do is replace the big old compressor with a modern smaller rotary compressor. there's a good paper on the net called "blowing snowballs in july" about high performance a/c in cars...