R12 conversion??

ColbyL

You guys rock!! I got 3 cans on order. One thing that’s strange, the smaller threaded ac connection is an odd size on my truck, it more like 3/16” instead of 1/4” on the low side, is this correct?

MazdaMitch

ColbyL in order to use the duracool you will need to get the 134a conversion kit adapters and put those on your r12 fittings so that you can use 134a gauges to charge it with the cans of duracool.

You'll also need some of them can taps that go on the top so that you can screw it in and screw it out so you can kind of save half a can.

Cusser

ColbyL You guys rock!! I got 3 cans on order. One thing that’s strange, the smaller threaded ac connection is an odd size on my truck, it more like 3/16” instead of 1/4” on the low side, is this correct?

Yes, that's correct. The US government mandated that manufacturers move away from the two same-size 1/4" flare caps because some folks were 2 stooooooopid to determine which was high/discharge and which was low/suction side. So manufacturers made the high side fitting a different size. Of course GM and Ford couldn't agree so adapters for them are DIFFERENT, so sad. GM and Toyota used one size adapter for the R-12 gauge sets, Ford and Mazda used a different size. I don't know about other makes.

Myself - I have R-12 high side adapters for both the Ford/Mazda one that I use, but I also have the Gm/Toyota type.

You can get a can side tap apparatus to use the Duracool with the R-12 gauges directly. I don't know if this one is for GM or Ford though https://www.autozone.com/cooling-heating-and-climate-control/a-c-adapter-fitting/p/santech-adapter-r12-1-4in-x-3-16in-a-c-adapter-fitting/952137_0_0?spps.s=2754&cmpid=LIA%3AUS%3AEN%3AAD%3ANL%3A1000000%3AGEN%3A22350391884&gclsrc=aw.ds&gad_source=1&gad_campaignid=22356757832&gclid=Cj0KCQjw_dbABhC5ARIsAAh2Z-QXNQyF1ggVg_pNDrg8VzNmQWGLG9-dRi8nmHQ_mae-n6kM7h0mBscaAlkeEALw_wcB&new_store_set=true

ColbyL

Yes, I picked up the R134 adapter kit Thursday and that’s when I noticed the small threaded adapter would not work. All the kits at the auto parts stores in town are 1/4” & 1/2” and my truck has a 3/16” & 1/2”. I’m just wondering is this standard from Mazda or did my truck get the small threaded connection changed out somewhere down the line.

ColbyL

10-4, thanks so much

kz6fittycent

Adding my $.02 to this DuraCool discussion. It's great - use it.
Just be sure to follow the directions for installation and recommended measurements, etc. Also, you can call them. I can't remember the guy's name up there in Canada, but he's super cool and very helpful.

I was lucky enough to find someone with a box full of R-12 and bought what I needed. If it leaks out, I'm going to fix my leaks and go w/ DuraCool.

Cusser

kz6fittycent I was lucky enough to find someone with a box full of R-12 and bought what I needed. If it leaks out, I'm going to fix my leaks and go w/ DuraCool.

Ebay has banned refrigerant sales at least for USA. Facebook Marketplace apparently still allows that.

My R-12 "stash" is from the days when it was under $2 a can; a couple of my cans are the older 14 oz. size.

I also will go to DuraCool in mine if need be, rather than doing R134a.

MazdaMitch

If you have a questionable system, I wouldn't want to track down, spend exorbitant amounts of money for it, and have it leak out.

Pulling a vacuum and it holding is one thing but it could leak once pressurized.

That's why I say use the duracool.
It's a REAL R12 drop in replacement that works with all oils. Not some mix of refrigerants that claimed to be a drop in replacement.

ColbyL

A head scratcher on the charging!! I put the new 134a adapter fittings on the threaded connections, received (3) cans of R12a today, pulled a vacuum for an hour, let it hold for an hour and then charged the system. I hooked up the blue (low side/small fitting) and started charging the system. The system pulled about 2 ounces, compressor come on then the system would not take refrigerant. I noticed the pressure was high as well ₇₅. Nothing worked on charging and the high side was reading low ₁₅. After looking at the lines under the truck, the low side had the larger red fitting. I was very skeptical but charged through the red line and it took the refrigerant and leveled out nicely and ice cold. Did Mazda get these backwards?

Cusser

My 1988 is still R-12, but your '88 appears to have the caps/adapters on the correct lines (as the original low side was 1/4" flare, and the original high side was 3/16" flare).

Here's a picture of mine with its R-12 fittings; note that I use a Sanden SD-708 Model 7225 not "officially" correct for 1988 but uses the 1988 factory "2 lines from a single compressor mount" fitting.

I don't have any experience with conversions from R-12, but I can't see anyone charging into the high side with cans, as the high side pressure would be more than the pressure inside the cans, and the cans could explode. This is why the feds made manufacturers go to a different size high side fitting for safety, so Goober and Gomer couldn't mix them up.

ColbyL it took the refrigerant and leveled out nicely and ice cold

Ice cold - then don't do ANYTHING ELSE !!!!

kz6fittycent

I am going to guess someone put those colored caps on backwards based on your story. Those are not factory low-loss connectors. Those are aftermarket and are just not the right color for the high/low side respectively. Mazda didn't get it wrong, someone else did.

kz6fittycent

Cusser Ice cold - then don't do ANYTHING ELSE !!!!

Agreed. I'm glad you posted a photo of yours. Looks @ColbyL has the caps in the right spots, so the question becomes what was causing the blockage? It COULD be a bad Schraeder valve not allowing the refrigerant thru. Or, it's something else - hard to tell not being there and watching gauges.

In any case @ColbyL if it's cold, leave it alone.

Axel-Breaker-Earl

See if you can swap the plastic caps.......if so, maybe you put them on wrong.

Cusser

Axel-Breaker-Earl See if you can swap the plastic caps.......if so, maybe you put them on wrong.

The R134a caps are different sizes - and yes - there are different sizes of those as well, depending on manufacturer. But R134a service gauge sets have on-off valves at the fittings; also at the service gauge manifold itself there are on-off valves, and those hoses fittings onto the service gauge manifold - I believe - can be swapped/same thread - but don't quote me, as I've never tried.

MazdaMitch

You're calling it r12a but if you got the duracool or any isobutane propane blend just like on the can and the website it says to connect it and let it get in the system you don't turn the compressor on until one full can is in and then you let it sit for about 30 minutes because it goes in as a liquid and then it has to gas off before you add half of another can and again you have to let it sit and equalize before you turn the truck on and start the compressor.

MazdaMitch

https://www.duracool.com/qr-codes/
Please read
With emphasis on "not running" and "wait 10 minutes" ...

ColbyL

Well Dang, I guess when all else fails read the instructions!! I "ASSUMED" this was just like any other install and charged it like I have done 20 other times with 134a on other vehicles. Thanks for clearing this up. The great news is the truck is cooling great and holding charge for the first time in at least 5 years.

kz6fittycent

I apologize too, I didn't realize you put Duracool in. Congrats - 'tis good stuff.

Cusser

Glad it's working.

Question: if you put DuraCool in it, why did you even bother to change the fittings to R134a type?

MazdaMitch

Cusser Question: if you put DuraCool in it, why did you even bother to change the fittings to R134a type?

Probably because it's hard to find r12 gauges these days.
I have a set but they are very old.

The 134 gauge set is easily obtained from Harbor Freight.
Also Duracool states that it is required to have already done "the conversion" before adding, for legal reasons I suppose.

Another thing is that the duracool cans come ready to use the brass can puncture taps just liek 134a cans, so that you can easily connect it to the charge hose on the gauge set.

None of this can be done without change the r12 fittings over to 134a fittings so that you can use a charge line or charge line on the gauge set.

Make sense?

ColbyL

It is DuraCool in it. I changed because the new fittings were cheap ($8), and my gauges have the quick connects. You sent me the link for the Santech adapter, I could have just taken the quick connections off and used the threaded connections. Either way seems to work well now. I'm just thankful the compressor was not locked up for sitting in a pasture for years and it is working, thanks for all the help!!