SPYoptics

I attempted to recharge my AC today, but failed. ~ Twice. First I bled the high end to see if anything was in the system. A little hot air came out and then nothing. So I figured it was empty. So I bought an R134a recharge kit w/fittings. I attached the hose to the low end and opened her up, while the ac was running. None of the cans would empty right, and at one point the bottle started backing freon out the top of those hose. The compressor clutch didn't start working until i attached to the system. So I know its getting in there, but somethings wrong. It won't suck in the freon right. Anyone have the same problem? Maybe I should somehow vacume the system again before attempting this again? I don't want this to get expensive. Help, its friggin hot out here.

woot1524

What year RX-7 are you doing this to? If it's 80's then it does not use R134a, it needs the illegal stuff R12. The only way you can safely upgrade to R134a is to rip it out of a mid 90's car and Frankenstein it onto your car. Other than that, find someone with R12. Then again if your car is a newer one then your compressor might be bad along with a whole slue of other things. My advice to you is either get some R12 or do the 2-40 rule, two windows down going 40

boosted1205

iTrader: (9)

You sure you're attching to the low side? The low side is the larger valve.


All the myth around R134 not compatible with R12 system is all bullshit. This comes from an A/C tech of 20+ years. The problem with people freezing their compressors are not oiling the system prior to new freon charge. If there is a leak in your system, of course the freon and oil will have escaped out of the system.
You need about 2 cans of oil, let the compressor run then add freon .
I've done this to a friends car that was leaking so I added a leak stop (when the substance escapes to atmosphere, it plugs itself). I've done this to 4 cars and no compressor freeze.
You can try it.

BLKTOPTRVL

I converted my 88 from R12 to R134a. The only thing I needed to change was the fittings.

I did the change because my old compressor had siezed. I put the R134a in after replacing the compressor, but it would not "take" because the replacement compressor I bought was bad and would not run. After getting a good compressor, it charged right up and has been running fine.

BLKTOPTRVL

I have a leak in my 94 condensor... First look says a rock pierced it. I will replace the condensor this weekend, but I would also like to know what sealant you speak of... In case there is another leak!

boosted1205

iTrader: (9)

They sell dyes that you inject to see where the leak is or buy a leak sealant where they sell R134 freon and kits.

inflatablepets

To do a proper job of retrofitting the A/C, (sevral years ago when i did the swap) you evacuate the old refrigerant and oil. Then replace the acumilator ,(strongly recomended because of the oil in it) Replace the oriface tube (if equipped) Clean the evaporater insides with brake fluid to remove all traces of oil and dirt. Close the system and evacuate the system to 28 to 29 in hg. Then put on the adapter fittings. start the car and turn on the A/C full blast. Add the oil charge. Then add the refrigerant to specs. Note you can use a container of hot water to raise the boiling temperature of the refrigerant so that it will all go into the system. Also if it works properly as a general rule the A/C air temp at the vents should be close to 40 degrees on an 80 ish degree day.

BTW R-12 is not illegal. Yo have to have a licence to buy the stuff. It's very expensive, but i don't know what current market prices are right now. Two years ago it was $5.00 per ounce.

mwpayne

R12A (also called freeze 12) is a direct replacement for R12, and it's cheap. Ready to order on ebay, I've used it in 3 cars that had R12, works like a charm, no new fittings or any of that crapola.

woot1524

Well fom what I've heard is that r134a is at a higher pressure and it can blow large holes in weak spots in a originaly r12 system

SPYoptics

Yeah so uhh, why won't it suck my R134a in? I can tell my ac IS working, just... not very cold at all. I figure I have like half a can in there. but the damn system won't suck it in. SHould i go get it vacummed by a shop and pay the expensive price, or attempt to fill it again and just buy some more R134a? .

GTUser

I have a question about preventive maintenance to an A/C system. I have had my 89 GTU for 4 years and the A/C never worked. I would turn it on and get no response. Well, I figured the system was bad and never had it tested.

A couple of weeks ago at a car clud meeting one of he guys brought his professional charging equipment, he is a residential A/C contractor with easy access to the good stuff. Anyway he hooked up my system and found that it had plenty of charge. He tested the main A/C relay and found it faulty. I was able to find a replacement relay and now the system is back in operation and working like a charm. My question, what PM does the system need? Should I have any worries since it sat for several years without running and is now back in operation?

If anyone runs into the bad relay problem and doesn't want to spend the $70+ to buy a new relay, and if you can't find a working main relay from an RX7 you can find the same relay, same part # and specs in late 80s Honda Accords.

inflatablepets

I beg to differ. For anyone doing this please read from this link, as it comes directly from the compressor manufacterer. Sanden made most of the compressors for the RX-7. Personally I'd believe what the compressor company says before a "so called A/C tech of 20+years" http://www.sanden.com/support/RETRO.html

Icemark

R12A and Freeze 12 are two different things.

R12A is hydrocarbon based and flammable.

Freeze 12 is not flammable and based on cloroflorcarbons.

Freeze 12 can be added to any R12 system without problems, but R12A will need the system evactated and need special oils added.

And for the people that claim R134 is compatible with R12 systems, they need to go back to A/C school. The oils used within the R134 freons will rot out the R12 rubber seals and lead to having to refill the system again and again, as well as lead to inferior cooling.

Of course an A/C tech might want that, so that the customer keeps coming back every summer for new freon and A/C system parts.

inflatablepets

Exactly. If people will read from the link I posted. When I did my old caprice I replaced the standard ester oil with pag oil. Interesting on the Freeze 12 stuff though. You learn somthing every day. BTW, Where can you buy iFreeze 12?

Icemark

I have seen it on Ebay and some air conditioning shops around the country stock it.

It is not banned (even though it is technically a freon), but I am not sure how safe it is to the world in the long run.

I personally have been using R12A, in my cars and have been very happy with it. It is flammable at high temps (at around 500F it becomes flammable), but it works twice as good as regular old R12, and won't hurt the atmosphere if it accidentally gets released.

It is legal to use in automotive products that have had R134 in them and commonly used in europe.

marcus219

******* woot woot for you man. Your right on the nose. I've done a couple r134a retro kits and what you just listed is the RIGHT way to do the conversion. Pulling vacuum on the system for at least 30mins is a must to check how sealed the system is. Replacing orfice tube and accumlator isn't 100% needed but is the right way to do things. And I can second r12 is not illegal, its illegal to produce vehicles with it, b/c of its ability to eat through our ozone layer, I just charged my corolla with r12!

inflatablepets

Mark, I did a little research on freeze 12, but I've also heard thet you can just put it in without a system evac. Do you or anyone else know anything about this?

inflatablepets

True, I didn't necissarily need to do all that, but the compressor had smoked and clogged the oriface tube. I also had to replace a bad hose assembly. That job cost me $300 to do at home, but I had a new system that was done right.

fanjet

I purchase my freeze 12 at any pep-boys,checker auto, or autozone however the sales person will ask you for your lisence in order to purchase it. Generally freeze 12 costs around $7.00 to $9.00 dollars per can. I have been using freeze 12 in all three of my rx7's, my truck and other car and have found it to work exceptionally well. Actually it works DAMN good!!!

Icemark

It does mix with R12 just fine. The only time you would want to evac the system would be if you had exposed the entire system to air (as is you took the A/C system all apart, then put it all back in). R12A works the same way, but you would need to add new compressor oil that makes the system cross compatible, before adding R12A.

But if you have low freon now, and you just want to recharge, then yes Freeze12 is fine to top off your existing system.

inflatablepets

Thanks Mark, I think I'm a few oz low. Ill have to get out the gauges sometime.

Mr. Gadget

So the correct oil for freeze 12 is ester? And, standard rubber orings are ok? I have a sytem completely apart, have the ability to easily replace all orings so I will be doing so now. Going with freeze 12. Just want to be sure on these two points.

poser7

Well inflatable pets there is another alternative... that's duracool. And freeze 12 is great product however in reply to your statement regarding the mixing of the petro based ref's they are mixable and won't need evac...federal law requires it!! 134a and 12 should never be mixed.... big nono.

In answer to spy optics q.... you most likely have a blockage in the system. It's most likelt @ the expansion valve. You need to get in there and get dirty to find it. And if I can give you any advice , don't use 134a, you won't be pleased w/ the results. Duracool or freeze 12 or r12a are better and perfectly safe. Ask BMW, they've been using petro based ref's for 10 years or so. As a matter of fact germany is big on it. 134 is not cold....these other products are. So, there you have it.

poser7

Oh yeah... and Duracool already has an oil charge.. It creates a low head pressure and THAT equates to longer compressor life and cooler a/c. You've already got the 134 connects and you'll need them for Duracool. It's great stuff; an aquaintance of mine got his a/c to cool to 17 degrees w/ it!! He let some out to bring it to the desired press. but it's great stuff. It'll take 12oz that's all. That's 2 cans. $7.99 ea. If I'm not mistaken it takes approx 2.5 can's of 134a @ 5.99 ea.....you do the math. Fix that blockage man....you'll lose the whole thing.

poser7

Come back to this and lemme know what you've got going on and I may be able to help you out.