There's also going with R-152a (Dust-Off) - works great as a drop-in R12 replacement, but it's a DIY only option. I've done a few cars with dust-off and have been satisfied with the results.

I know the 134a cars have a compressor that says "134a" on the back. I don't know what all changed with it or if it was just pre-loaded with the proper oil.

Dale

 

I'd be curious to see what is actually different from the R-12 Denso system and the R-134a Denso system in the FD. I'd guess they're almost the same with just some minor revision changes; If they're not, perhaps we could document what to upgrade?

I may do some digging in the part catalogs.

 

I think a lot of the AC parts are NLA at this point, but the parts catalogs may shed some light as to what parts were revised. But, some may be the same, such as the driers, but the 134a version may be pre-loaded with the 134a oil instead of mineral oil. I imagine when they are installing them at the factory they have the driers and compressors pre-loaded with oil.

The lines would be interesting, I imagine they would have had to upgrade to the barrier hoses.

I know Mazda did a TSB sort of thing showing the new O-rings for all the AC fittings to the "green" o-rings that are 134a compatible. They work with any refrigerant, though.

Dale

 

I made a new thread to not go too far off topic here.

https://www.rx7club.com/3rd-generati...stems-1137448/

 

Quick question.

If my car came equipped with MANA. Is it possible to take everything out and do a complete swap to Denso?

Will the harness and all under the dash connect up pnp?

 

I'm officially rescinding my endorsement of the envirosafe ES12a HC refrigerant, so please ignore the recommendation above. I always charged with traditional refrigerants when I did it professionally, but tried the alternatives on this car after reading success stories on forums.

After struggling several seasons to get decent vent temps in the 7 with ES12a I finally decided to put some real refrigerant in the car. Results were positive and immediate. It blew mid 40's from the vents with half a charge and was getting 39F vent temps with 21 oz of the good stuff (what the 1993 car came with). Sight glass cleared at full charge. 30 psi low 175 psi high at idle.

I am reasonably certain that the same results could be had with R134a or even R152a (duster - there's a great thread on it in the FC forum). I would have tried those, but I have mineral oil in my system and didn't want to pull the compressor to drain it. You need PAG oil for those refrigerants. We always used the mineral oil compatible BG Frigiquiet R134 oil at our shop and had great results from conversions.

 

I should update mine as well, I don't get 38F vent temperatures. I get 37.9F vent temperatures

95F ambient temperatures

 

Since I'm in North Dallas (Allen), out of curiosity which shop did you take it to?

 

I tried all three on mine for the fun of it (and to verify I got all the leaks/problems on my system taken care of before I put anything expensive in it). I didn't write down the temperatures I saw, but I can say in the Texas heat ES12 was noticeably warmer than 152A or 12. ES12 performed fine until it was over 90-95 outside + humid, so I guess for some climates its alright.

It's harder to call between the dust-off stuff and 12. I think 12 won at idle noticeably, but dust-off did ok at idle, and was pretty good once the rpms picked up even a little. I know there are some good write-ups on here that go into detail on the differences. If I remember right, it pretty much lined up with what I noticed.

 

Did you find this shop in San Diego? I'm looking to recharge mine as well.

 

This dude (I think his name is Marion?) got me running right. It's literally just one guy and a bit of a janky shop but he was extremely nice and really knew what he was doing.

https://goo.gl/maps/jbpPr8w1TPq4YCkW7

2630 Northaven Rd #107, Dallas, TX 75229

 

While these results are certainly chilling (knee slap), an AC performance test is typically done on the highest blower setting. Get 37* on speed 4 and I’ll really be impressed, and probably suggest wearing a sweater in your car.

*update*

Drove mine today. 107*F ambient here in Phoenix and my R12 system was putting out 50*F from the vents on blower setting 1 and 65* on blower setting 4. Not the greatest. I have a Greddy V mount so the condenser sees a bit more airflow than a front mount.

Matt

 

LOL, how do you even survive in your car with 37 degrees? Is it even possible? You need to get an AC as fast as possible, you're getting cooked alive in your car. My dad's old Ford also had no AC, he was wet every time when he drove that car in the summer time, until once I decided to make him a surprise and called the guys from Aircon Servicing. They did a great job, a smooth and fast installation and now the temperature inside is perfect. Driving the car in 40 degrees is not a problem anymore and I am no longer aware of my dad's safety when he drives in this heat.

 

I think he was getting 37F out of his vents, not 37C (99F)

40C (104F) is a death wish with no AC. That's getting close/into the temperature range where even on a motorcycle completely naked you would be liable for a heat stroke eventually. The air simply is too warm to effectively cool your body. Add the reduced airflow and greenhouse effect of a normal car cabin and that's playing with fire. Add the heat that our engines produce and you're basically just roasting yourself.

 

i have my own stash saved so I haven't purchased any from Napa so I can't be certain if they actually have it or can get it...... but anyone on here desperate enough for it and willing to pay for it with along with an epa license can try. On napaonline.com it does show some stores that has R-12 can for pickup or at least get it within a few days. It's pricey at $62 a can but I'm sure there are some who will pay for it to get the desire temperature output from their a/c

 

I've bought vintage cans of R12 off Ebay before, you do need an MVAC certification to buy it (I have that) but it's another option. I've found cans for a good price in the past. Not sure what they are going for now.

Dale

 

Just wanted to add to the list, but I have a MANA evaporator that's R134a, so I guess these exist too. I tried googling the part number FD31-61-520 but I've only seen one listing from a Mazda dealership in Canada with the description "COOL UN" (I guess cooling unit). It does turn up in a couple of parts lists for 95s though, so I think this is from a 95 model. It looks nearly identical to my 93 MANA except it has the smaller plastic housing to accommodate the passenger airbag. The expansion valve fits the same.