R12 to R134 convertion..need help

[salvageV6]

I know a guy who runs pure propane in his A/C system, mechanical engineer of course.

Old beemer of course 1982.

Anyway I'd start with 7 cans Bob which should be about 80% of capacity, if buying go for 10-12 cans.

Make sure you vacuum it out and has the proper oil for the Duracool which may just be the R12 oil. If you need to switch out the oils from a 134a conversion I'd get a new drier which will remove a lot of the 134a oil in the system and allow you to pour in some new oil before installing it.

Use some gauges too to help note the proper pressures and charge.

 

[TurboDave]

Hi,
I don't blame you for being disappointed with your 134a conversion.The refrigerant is not a good retrofit for R12 systems.I have used it for a few years in my cars,and performance is acceptable, so I have left them alone, but honestly,if you have a tight system, stick with the 12.The reason dyes have become so prevalent is that electronic detectors, even the best, have a hard time picking up even moderate 134a leaks. It kind of ticks me off that I bought a Hitchcock hot diode detector a while back, aint worth a hoot for small leaks. $450 , bye bye. 134a is notoriously hard to detect anyway, hence the dye.The best retrofit stuff I have run into is RB276, a blend which, as far as I can tell from reading the EPA stuff, is legal. Duracool and Freeze12 and such are hydrocarbons, I think. Putting a potentially flammable product in an AC sytem makes me nervous. RB276 ,as I said before, is a blend of two or three refrigerants, contains the oil needed, too. The best thing is, it brings head pressures way down, so the compressor isn't beating it's brains out, like it does with 134a.
These are my opinions, borne of some experience. When either of my cars has AC problems, I intend to follow my own advice.Until then, I also follow the dictum: don't fix it if it aint broke! Good luck with your situation.

So, do I understand you correctly. Can RB276 be put right into an R12 system with no changes/mods, etc.?? My GN's sat out in MI winter weather last year under covers, but for some reason, neither A/C system cools now (they had been working fine for 20 years). So I assume the non operation over the course of the winter must have caused them both to loose their refrigerant to some extent.
A friend can get RB276 but isn't sure of how it coexists in an R12 system.

 

[robbyc]

propane is one of the gases in dura cool and hc 12 if you use dura cool it takes about three to four cans in a buick system but if in doubt go by pressures
robby

 

[TurboDave]

So, do I understand you correctly. Can RB276 be put right into an R12 system with no changes/mods, etc.?? My GN's sat out in MI winter weather last year under covers, but for some reason, neither A/C system cools now (they had been working fine for 20 years). So I assume the non operation over the course of the winter must have caused them both to loose their refrigerant to some extent.
A friend can get RB276 but isn't sure of how it coexists in an R12 system.

No info on this???

 

[Bob Avellar]

'
The G-body system holds 3.25 lbs.

According to your 3.25lb figure thats 52 oz.
According to Duracool:
Requires only 40% of charge by weight of R-134a and 35% of CFC-12

35% of 52oz. equals 17.2 oz. That's just under 3 of their 6 oz. cans.

Supposedly it is" Up to 35% more efficient than R-134a - Moderately more efficient than CFC-12"

Auto ignition of ~1635°F is ACTUALLY a higher auto ignition than R134a which is 1328°F

Compatible with mineral & synthetic oils including Pag & Ester - No Oil Change Is Required.

BTW I mistakenly ordered 3 cans twice the other day due to something weird with the way the Paypal pages appeared on my browser. I tried to cancel 1 order of 3 but I gave up. Next day I get an email from Duracool if I made a mistake by ordering it twice (they obviously looked at the 2 identical orders and picked up on it). Paypal already sent the $$ but Duracool immediately sent me a notice of my refund. I thought that was pretty nice. They could have just done the easy thing and sent all 6 cans. Of course now I'm wondering if I should have ordered at least 1 more can to begin with.
Hey, I'll try most anything at least once. I am not concerned about blowing up due to my AC system. I'm more afraid of blowing up my motor. Hell, I have about 1 1/2 gallons of methanol sitting in an aluminum tank where the stock battery used to be, a full tank of fuel at the rear of the vehicle, high pressure fuel lines stretching from front to rear, and tons of wires in harnesses that can carry large currents from the rear mounted battery, battery acid, charging gasses,cell phone microwaves bombarding me,bugs hitting the windshield, loose nut on my weebly rod...

 

[robbyc]

i use dura cool to this day in my shop and have no problems do dont worry