High and Low side a/c

67Dart273 said
The other thing here, is, you cannot just buy 134A conversion fittings and dump that refrigerant into an R12 system.

But 134A fittings --to hoses-- are standardized. The high side is stupidly larger, and red, and the low side is stupidly smaller, and blue. You cannot accidently interchange as with older R12 fittings, which were pretty much all 1/4 SAE flare, or no.4 SAE flare. That is NOT JIC and NOT AN. That is SAE

(Why stupidly? Because a low pressure system flows less than a high pressure one, the low side system should have a larger size port to flow quantity. If you are evacuating a system, the blue should have been larger. Stupid)

Some later model stuff, like my (former) 86 and 87 Rangers, had a proprietary small flare fitting on one side I don't remember which.

These are R12 manifold/ hose adapters.........to R134A system adapters

https://www.amazon.com/dp/B07T9HFBCH/?tag=fabo03-20

134a Quick Coupler, AC R134a Adapter Fittings Quick Connector, 1/4" SAE Male Flare High/Low A/C Freon Manifold Gauge Hose Conversion Kit

View attachment 1715580698

Those are some good looking 90's. I got the fittings on - the high side would not take a shrader so I left it in the old fitting, and will find out when I put some gas in it if the red hose will still read. The blue one was pretty easy, I dremmeled down my smallest needle nose to make a tool. I keep wondering if I need to buy a cheapish manifold hose set for this. The manifold gage hoses I borrowed from Reilly's Auto has the rubber hose pieces that fit at the bottom inside all the hose hookups are broke and I've been running this vacuum pump for 2 hours and it won't get better then -15 - halfway to the 30 mark. I shut it off once and it didn't go back any so hopefully no leaks in the a/c. The searches I have done for only getting to -15 say its either the pump or the hose connections so thats why I wonder about the cheapish purchase of a manifold hose set. Is -15 good enough?