Need AC adapter

[The_Jeff]

Have a generic AC manifold set. Its yellow hose input takes what seems all the world like a male 3/8-24 brake line nut with a bubble flare (actually a 45 degree angle.) Also have some home AC adapters that take the same thing in 7/16-24.

Have a r134a can tap that has a 7/16-ish (actual diameter, nominal 1/2") ACME male thread output.

What do I need to bring these two together, and, bonus question, why are they trying to not let me do this?

 

[The_Jeff]

Further research indicates this might be accomplished with an R12 to R134a adapter. R12 is not at all involved in this, want to charge a 134a car. Are the manifold hoses still threaded with obsolete tech just because that's how it's always been?

 

[thastinger]

Are you opposed to something like this
https://www.amazon.com/R134A-Car-Re...d2lkZ2V0TmFtZT1zcF9zZWFyY2hfdGhlbWF0aWM&psc=1

 

[The_Jeff]

I had something cheesy like that but it stopped passing gas (hah!) and since I have a "real" manifold I'm trying to do it "right."

 

[Urshurak776]

Subject line misleading! LOL I was expecting an electrical adapter or something.

 

[Nukeman7]

Have a generic AC manifold set. Its yellow hose input takes what seems all the world like a male 3/8-24 brake line nut with a bubble flare (actually a 45 degree angle.) Also have some home AC adapters that take the same thing in 7/16-24.

Have a r134a can tap that has a 7/16-ish (actual diameter, nominal 1/2") ACME male thread output.

What do I need to bring these two together, and, bonus question, why are they trying to not let me do this?

I think one of these adapters will accomplish your objective:

R-12 to R134a Coupling Adapters

 

[The_Jeff]

^ That's about what I wound up getting locally at NAPA for $16, sheesh, big markup for them. P/N for posterity: 78-3199/ NTE 783199 ADAPT 1/2ACMEFX1/4MFL "you sir are a mouthful."

Works great, got the kid's Prius down to a 43' vent temp in 70+ dewpoint swampy air.

Only question remains, why do they sell stuff that doesn't fit with other stuff that you'd expect to go together?

 

[mk378]

The 3/8 thread (flare for 3/16 tubing size) was used on the high side of later R-12 cars so people couldn't put their basic cheap can hose on the high side by mistake.

All the fittings were changed for R-134a to discourage mixing of refrigerants during the transition era. A mixture of the two refrigerants has markedly different pressure-temperature properties than either one alone and will not work.

 

[The_Jeff]

All the fittings were changed for R-134a to discourage mixing of refrigerants during the transition era. A mixture of the two refrigerants has markedly different pressure-temperature properties than either one alone and will not work.

Good history. But why, in present day, would one buy a tap for a 12 oz can of r134a that has ACME threads that don't fit a gauge set/ manifold? What's it for, then? (And I'm not asking you specifically, mostly ranting.)

The manifold came with adapters to allow R410a etc to fit in case someone wanted to monkey with their heat pump. But not the common use case of a nearly modern car!

 

[Nukeman7]

Good history. But why, in present day, would one buy a tap for a 12 oz can of r134a that has ACME threads that don't fit a gauge set/ manifold? What's it for, then? (And I'm not asking you specifically, mostly ranting.)

The manifold came with adapters to allow R410a etc to fit in case someone wanted to monkey with their heat pump. But not the common use case of a nearly modern car!

The problem is with the yellow manifold hose, not the valve tap for the R-134a can. Based upon your disclosure that the gauge set came with R-410 adapters, I suspect the "generic" manifold hose set was configured for home HVAC service instead of automotive systems. The older R-12 fittings are compatible with the R-22 freon tanks used in home/residential HVAC systems prior to 1996. The hose ends on gauge sets intended for R-134a systems have the 1/2" ACME threads.

 

[SC Maintenance]

I am a complete amateur at this, but I bought a cheap gauge set from Harbor freight and a standard R134 Can tap on Amazon and everything fit.

I think as mentioned you got something designed for something other than automotive.

As an aside, I recently found out you can still buy R-12. Well I can't - but they still sell it for industrial use, and its been re-purposed or harvested from old equipment - if you have the right license.