Air conditioning newby... DIY your pay someone else?

[Stainless]

I am about done with other restoration projects on my car and will soon want to get the AC working. My system is still set up to run R12, but it seems like the logical thing to do at this point in time is to consider switching to R134a.

I was considering taking my DeLorean to a local shop that has done work on a friend's AC with good results. But I know that many of you do your own AC work, so I want to see if I could/should acquire the necessary tools to be able to work on the AC myself. I imagine that the shop would charge me a few hundred dollars to diagnose and repair my AC. I received a Harbor Freight catalog that shows the following prices on the tools that I think I would need:

-A/C Manifold Gauge Set: $60
-2.5 CFM Vacuum Pump: $104
-Electronic Freon and Halogen Leak Detector: $70
Link to tools: http://www.harborfreight.com/automotive-motorcycle.html?CatPath=All%2BProducts%252F%252F%2 52F%252FAutomotive%2B%2526%2BMotorcycle%2F%2F%2F%2 FRefrigeration&RequestData=CA_CategoryExpand

I have had good results with many HF tools, but don't know if these are any good. A recharge and recovery machine is $1600 from HF, so I would still need a shop to assist with recovering any remaining R12 in the system. It looks like I could get the tools listed above for around $250, which is what I imagine would be at least what I would spend at a shop, if not more. I have not included the price of refrigerant in my price list. Am I missing any other vital tools to be able to do my own AC work? I am very much the type of person that does as much work on my own cars as I possibly can, but I have never touched any car's AC system. What approach do you recommend?

[David T]

I am about done with other restoration projects on my car and will soon want to get the AC working. My system is still set up to run R12, but it seems like the logical thing to do at this point in time is to consider switching to R134a.

I was considering taking my DeLorean to a local shop that has done work on a friend's AC with good results. But I know that many of you do your own AC work, so I want to see if I could/should acquire the necessary tools to be able to work on the AC myself. I imagine that the shop would charge me a few hundred dollars to diagnose and repair my AC. I received a Harbor Freight catalog that shows the following prices on the tools that I think I would need:

-A/C Manifold Gauge Set: $60
-2.5 CFM Vacuum Pump: $104
-Electronic Freon and Halogen Leak Detector: $70
Link to tools: http://www.harborfreight.com/automotive-motorcycle.html?CatPath=All%2BProducts%252F%252F%2 52F%252FAutomotive%2B%2526%2BMotorcycle%2F%2F%2F%2 FRefrigeration&RequestData=CA_CategoryExpand

I have had good results with many HF tools, but don't know if these are any good. A recharge and recovery machine is $1600 from HF, so I would still need a shop to assist with recovering any remaining R12 in the system. It looks like I could get the tools listed above for around $250, which is what I imagine would be at least what I would spend at a shop, if not more. I have not included the price of refrigerant in my price list. Am I missing any other vital tools to be able to do my own AC work? I am very much the type of person that does as much work on my own cars as I possibly can, but I have never touched any car's AC system. What approach do you recommend?

One way is to do all of the "heavy lifting" meaning you change all of the parts (hoses and accumulator) and let the shop do the leak-testing, evacuation and charging. Talk to your local shop and see how cooperative they will be. They could pull out the R-12 before you start. I would recommend you stay with R-12. It is not *that* expensive and you don't need all that much. You can get it on E-Bay. Unless you expect to use the tools more than once it really doesn't pay. You should include an electronic vacuum gauge and a tank of Nitrogen with a regulator in your tools list. You don't need a leak-tester, soapy water (leak-test solution) is better and a LOT cheaper. You should also change the oil in the compressor.
David Teitelbaum

[Farrar]

If you have the time, do it yourself. I replaced the compressor, all hoses, accumulator, switches, etc., and added a high pressure switch since my car is too early to have one from the factory. I had some help replacing the evaporator, but you could also replace the evaporator and condenser yourself if you wanted to. Follow the instructions in the workshop manual and you'll be fine. I also suggest taking pictures of everything so you can have a visual reference for how everything goes back together. I wouldn't trust a shop to do it, let alone consider that it would probably be $2k or more for a shop to have done all of that for me. It can be done, just be patient and remember to post your questions on DMCTalk if you get stuck. :) Good luck!

Edit: Don't buy the cheap plastic manifold gauges from Harbor Freight. Get a brass set from Amazon. They'll last a lot longer. Also, get the two-stage 3 CFM pump from HF instead of the $104 you listed. It's $154, and they have a 20% off $100+ coupon running right now if you subscribe to their e-mails.

[Bitsyncmaster]

If you have a good air compressor, you can get the vacuum with a $30 tool from HF or elsewhere. They work great but when you do the 1 hour draw to get the moisture out, I do it in steps, draw down, close valve, wait until little loss of vacuum and keep repeating until is has no vacuum loss.

[Stainless]

If you have a good air compressor, you can get the vacuum with a $30 tool from HF or elsewhere. They work great but when you do the 1 hour draw to get the moisture out, I do it in steps, draw down, close valve, wait until little loss of vacuum and keep repeating until is has no vacuum loss.

I have an excellent 26 gallon Craftsman upright air compressor. Do you have a link or something to help me find this $30 tool you speak of?

[Bitsyncmaster]

I have an excellent 26 gallon Craftsman upright air compressor. Do you have a link or something to help me find this $30 tool you speak of?


http://www.harborfreight.com/air-vacuum-pump-with-r134a-and-r12-connectors-96677.html

[kings1527]

Great topic. You are in the EXACT same position I was in back in March. At the time, I knew two things: 1) you turn the AC on to make it get cold, and 2) AC systems take refrigerant. The thing with working on your own AC is that you have a little bit of everything involved. You have electrical, temperatures, physics dealing with pressures, mechanical operations, a lot of theory, etc. It's not hard but it's a lot of information. There can be a lot of troubleshooting involved. Given all that, if you research the topic a lot, pick up the Haynes Heating and AC Book, and take a look at several awesome videos on Youtube dealing with AC, I'd say do the work yourself.

I'm working on an entry on my blog right now on my AC work and it's so involved but I'm close to finishing. I'll try to make a lot of progress in the next few days but I think you might benefit a lot from it since I'm putting a lot of info in it dealing with what all of the components of an AC system do and how they work. It's easier to diagnose something when you have an understand of all the players involved.

As far as converting goes, I think the only real reason would be for cost. Like Dave T said, R12 isn't that expensive and you don't need much. If you have a tight system, it should work for several years before you have a problem. If you have access and can afford R12, I'd stick with that. If you're looking for a recovery machine, you can usually find one on Craigslist such as the Snap On ACT 3000. If you really want one, usually you can find it for about $200-300. Craigslist and eBay are perfect for finding R12 and tools. And that's another 'downside' to doing your own AC work: most of the tools you use are only indigenous to AC work. But I'd recommend getting a solid AC gauge set and I think the Yellowjackets are the best.

Bottom line, AC work isn't all that difficult but it does take a lot of time to learn what's going on and it takes time to do the work. Right now, I'm getting 38-39 degrees at my vents and on a good day I'll get 36 degrees. And that's coming from a hack who had no idea where to start. As soon as I finish up my write-up, I'll let you know and I think it'll have some good info gathered up from multiple sources that'll help you.

[sdg3205]

Stay with R12 if you can.

I have one car with r12 and one with 134a. The converted car is giving me issues. The r12 blows really cold, too.

[jangell]

As soon as I finish up my write-up, I'll let you know and I think it'll have some good info gathered up from multiple sources that'll help you.

I am also very interested on that write-up, as I have to do an AC overhaul in the near future.

-- Joe

[Jacko]

I am also very interested on that write-up, as I have to do an AC overhaul in the near future.

-- Joe

I am interested in this thread because I just learned that 4915 needs a new evaporator. Last month I had to have
a new evaporator in the Jag ... cost $2700.00. Wonder what it'll cost for the D? It's about the same job I think ... Rip out
the dash to get to it.8)

[kings1527]

I am also very interested on that write-up, as I have to do an AC overhaul in the near future.

-- Joe

No problem, Joe. I'll have it ready here soon. And by no means do I proclaim myself to be an AC wizard. Not in the slightest. Several of the people on this very thread helped me through some issues and all I've done was gather up all the info along the way and put it into one place. It's going to simply be a story of what worked for me and I have some excellent AC now. I'm sure I didn't do some thing(s) right! Fortunately, this isn't an exact science.


I am interested in this thread because I just learned that 4915 needs a new evaporator. Last month I had to have
a new evaporator in the Jag ... cost $2700.00. Wonder what it'll cost for the D? It's about the same job I think ... Rip out
the dash to get to it.8)

Actually, the dash will stay completely in place. No need to remove it but just about everything underneath the dash will come out and that's where the cost of the job is in terms of labor. I vaguely remember asking the guys at DMC CA about just the labor involved (it's A LOT of hours) with an evaporator replacement and I think it all comes down to personal time involved. Do you have a family at home and you work a 9-5 job five days a week and you want it done so you can drive your car ASAP? It'll probably take you a good while to do it yourself and you might want to pay to have it done. Do you have the time and patience? Then you can totally do it yourself. It's really not that bad. I replaced the evaporator in my car on this go around, in fact I replaced everything but the condenser. It's not hard but it's one of those things that just takes a ton of time, particularly when it's your first time doing it. If I had to do it again (I hope not) it'd take far less time. I took lots of pictures that should help you prepare and let you know ahead of time on what to expect with that project.

[Farrar]

I replaced the evaporator in my car on this go around, in fact I replaced everything but the condenser.

Me too. I'd estimate the evaporator alone took twelve hours.

12 hours x $80/hour + shop materials, etc. = ka-ching!

[kings1527]

Me too. I'd estimate the evaporator alone took twelve hours.

12 hours x $80/hour + shop materials, etc. = ka-ching!

Seriously! That's a chunk of change. And that hourly rate isn't so bad. Several shops in the LA area are going to be $120/hr and up! Personally, I say invest the time and do it yourself just for the knowledge gain. I actually had a great time learning all about AC. For some reason I found it real interesting.

[rothsean]

I bought the pressure test, add Freon, recover combo kit from Harbor Freight today. It is made for a 134A Freon system.

They did not have adapters for it to connect to R12 systems. It looks like the lines will connect to R12 connections if I don't use the included 134A quick connectors.


Has anyone else had experience with this?

[NightFlyer]

There's some really good A/C info/discussion taking place over on DMCToday.com, including reference to Napa R-12 to R-134a service fittings, exploration of hydrocarbon based refrigerants, such as 12a, vs flurocarbon based refrigerants such as R-134a, and even a complete 'how to' video showing evacuation, flush, and vacuuming procedures.

Check it out here:
http://www.dmctoday.com/showthread.php?48-Freon-on-Sale-at-Big-Lots&p=1451&viewfull=1#post1451

[rothsean]

I just want to know what I need to buy so that this 134a Manifold kit that I have can test and refill my r12 system cars.

[NightFlyer]

I just want to know what I need to buy so that this 134a Manifold kit that I have can test and refill my r12 system cars.

If I'm understanding your situation correctly, and I believe I do, then there's one of two way you could do it:

1) Get r-134a to r-12 hoses

http://i.ebayimg.com/t/R12-to-R134a-Flex-Hose-Adapter-Set-Use-w-R134a-Gauges-/03/!B,kqGm!!mk~$(KGrHqQH-CYEqvCGYuhlBKsDCVSJRQ~~_12.JPG

http://www.ebay.com/itm/R12-to-R134a-Flex-Hose-Adapter-Set-Use-w-R134a-Gauges-/171066564474?pt=LH_DefaultDomain_0&hash=item27d45c9f7a&vxp=mtr

2) Get r-134a service port adapters for your r-12 service ports

http://partimages.genpt.com/largeimages/1118966.jpg
http://partimages.genpt.com/largeimages/1410285.jpg

http://www.napaonline.com/Catalog/CatalogItemDetail.aspx/A-C-Retrofit-Service-Valve-Adapter/_/R-TEM409902_0215039856
http://www.napaonline.com/Catalog/CatalogItemDetail.aspx/A-C-Retrofit-Service-Valve-Adapter/_/R-TEM409903_0215039683

[rothsean]

Thanks, I just ordered that kit with the hoses and adapters.

[Ron]

I just want to know what I need to buy so that this 134a Manifold kit that I have can test and refill my r12 system cars.Depending on the adapters that came with the kit, you might need one that will allow you to feed the can into the gauge set so you can purge them and not have to keep taking the low side on and off to fill.
Not sure what you have in them or are going back with, but keep in mind different refrigerants require different oils.


There's some really good A/C info/discussion taking place over on DMCToday.com, including reference to Napa R-12 to R-134a service fittings, exploration of hydrocarbon based refrigerants, such as 12a, vs flurocarbon based refrigerants such as R-134a, and even a complete 'how to' video showing evacuation, flush, and vacuuming procedures.

Check it out here:
http://www.dmctoday.com/showthread.php?48-Freon-on-Sale-at-Big-Lots&p=1451&viewfull=1#post1451

If I'm reading that right, HC-12a, a "drop in" for R-12 (AKA Freon-12 ) & R-134a, information is being confused with FrostyCool 12a (e-Bayer's title says, "FrostyCool R12a"!), which is to be used on "retrofitted CFC-R12" (AKA R-12) & R-134a systems.
12a also says, "can be used to replace....R-12 substitute refrigerants".

Looks like illegal bombs and snake poots. Apples and oranges anyway. Be careful!!!

[Farrar]

Bits of the legalese here (http://www.epa.gov/Ozone/snap/refrigerants/hc-12a.html) are confusing, but these two parts stand out to me:

"Many states prohibit using flammable refrigerants in motor vehicles, regardless of which original refrigerant was used in the vehicle."

"It is illegal to use hydrocarbon refrigerants like HC-12a® and DURACOOL 12a® as substitutes for CFC-12 in automobile or truck air conditioning under any circumstances."

[rothsean]

What do you guys mean by different freons need different oils? I have to add oil to the system too? I just figured I could check the pressure and if it is low add some Freeze 12.


Have any of you used Freeze 12 before?

[Ron]

You can top off R-12 with Freeze 12 and not worry about the oil. Freeze 12 fittings are a whole different animal though.
You could buy a can tap that pierces (http://www.aliexpress.com/item/CAN-TAP/498037659.html) if the Freeze 12 didn't come in a kit with fittings. (I thought that stuff was about gone long ago...worked ok.)

[NightFlyer]

If I'm reading that right, HC-12a, a "drop in" for R-12 (AKA Freon-12 ) & R-134a, information is being confused with FrostyCool 12a (e-Bayer's title says, "FrostyCool R12a"!), which is to be used on "retrofitted CFC-R12" (AKA R-12) & R-134a systems.
12a also says, "can be used to replace....R-12 substitute refrigerants".

Looks like illegal bombs and snake poots. Apples and oranges anyway. Be careful!!!


Bits of the legalese here (http://www.epa.gov/Ozone/snap/refrigerants/hc-12a.html) are confusing, but these two parts stand out to me:

"Many states prohibit using flammable refrigerants in motor vehicles, regardless of which original refrigerant was used in the vehicle."

"It is illegal to use hydrocarbon refrigerants like HC-12a® and DURACOOL 12a® as substitutes for CFC-12 in automobile or truck air conditioning under any circumstances."

HC-12a, FrostyCool 12a, RedTek 12a, etc are essentially all the same product - you can verify this by looking at the MSDS of the various 12a products. BTW - the 'HC' merely stands for 'hydrocarbon,' while 'CFC' stands for chlorofluorocarbon. 12a products are basically a blended mix of highly refined butane and propane. It is a hydrocarbon based product, as opposed to a fluorocarbon based product such as R-134a is.

Personally, I believe the concerns about potential explosive flammability from the use of such a refrigerant is highly/greatly exaggerated.

First off, gasoline vapors are way more explosive than any 12a product is. Second, various tests performed have essentially confirmed that a perfect storm of conditions is required in order to cause the ignition of a 12a product that has escaped from an a/c system. You actually have a greater chance of being struck by lightning or being involved in a plane crash in your lifetime than such a perfect storm occurrence happening. Keep in mind that there have been no reported explosions having been caused by the use of a 12a product. Third, if you're concerned about refrigerant leaking into the cabin of the car, then perhaps you should consider the fact that R-134a is a known carcinogen, while 12a is wholly benign, not to mention that R-134a is also flammable (just not as much). Fourth, several users of this very forum have reported using 12a products with great success - try searching the term 'redtek' for a few examples. Fifth, because hydrocarbons are more efficient at cooling than flurocarbons, you actually need less refrigerant to obtain the same degree of cooling, 14.4oz of 12a vs 36oz of R-134a, and at lower pressures, which means less compressor cycling. Sixth, hydrocarbon refrigerants have been used in commercial/industrial applications for over half a century and have an excellent performance and safety record.

Finally, it's important to keep in mind that 12a refrigerants are not proprietary, nor are they at all patented.

R-12/Freon was a patent/trademark of DuPont until 1995 when their patent expired. Curiously enough, 1995 is the same year that R-12 was outlawed in all new build vehicles sold in the US. R-134a is also patented by DuPont.

So, before blindly accepting either state law or the EPA's ban on the use of 12a products in automotive a/c systems, you have to ask yourself why did they really do this. After all, it's still legal to sell, just not legal to use. Thus, if it was really that bad, and the government was truly concerned about our safety, then wouldn't they prevent the sale of it as well? Remember that DuPont spends more than the GDP of several small and medium nations lobbying the federal and state governments annually.

I'm just saying...

[Jason]

Keep in mind that there have been no reported explosions having been caused by the use of a 12a product.
I'm just saying...

There is this http://www.imcool.com/articles/aircondition/Porsche_928_Refrigerant_Fire.php

That said I pretty much agree with NightFlyer.

Badly written laws are the reason 12a isn't used more often. Even though its completely harmless to the environment to release 12a to the atmosphere, legally you're still required to use a dedicated 12a refrigerant recovery system when emptying a system that has 12a. So if you have 12a in your AC system no shop is going to want to touch it.

Also, the law requires that the EPA explicitly approve any replacements for R12. There is no such requirement for R134a. So while it's legal to use 12a in R134a systems (in states where it hasn't been banned), its not legal to use it in R12 systems. It's also illegal to convert from R12 to R134a with the intent of using 12a.

[Ron]

HC-12a, FrostyCool 12a, RedTek 12a, etc are essentially all the same productWhile the first link indicates HC-12a is a drop in for R-12 systems, the second link indicates FrostyCool 12a is for retrofitted R-12 systems (twice). So either one of the links are wrong, or, they are not to be used for the same purpose. "Drop in" V/S "Retrofit".
See?



There is this http://www.imcool.com/articles/aircondition/Porsche_928_Refrigerant_Fire.php

That said I pretty much agree with NightFlyer.

Badly written laws are the reason 12a isn't used more often. Even though its completely harmless to the environment to release 12a to the atmosphere, legally you're still required to use a dedicated 12a refrigerant recovery system when emptying a system that has 12a. So if you have 12a in your AC system no shop is going to want to touch it.

Also, the law requires that the EPA explicitly approve any replacements for R12. There is no such requirement for R134a. So while it's legal to use 12a in R134a systems (in states where it hasn't been banned), its not legal to use it in R12 systems. It's also illegal to convert from R12 to R134a with the intent of using 12a.

+1 I'm with you on all of this. (I'm not on either band wagon there ;-)

I will say comparisons between the explosiveness of fuel and refrigerants would have to consider the refrigerant (any type) is under relatively extreme heat AND pressure (max 75 V/S 300psi in a D) when the system is operating.
Doesn't seem to matter in the first place to me. We don't have a lot of reasonable choices for fuel... No sense in asking for it over a few bucks when it comes to refrigerants.

[David T]

There is a lot of confusion out there about "drop-in" replacements for R-12. Basically there are two kinds of drop in replacements, blended refrigerants (using different types of freon mixed together) and HC based refrigerants using Propane and Butane. As noted it is illegal to use HC based refrigerants in a mobile application (cars). In fact, it became so common in California for people to go to Mexico for A/C work on their car (it was a lot cheaper) where they would use HC refrigerants, that when you go to trade your car in the dealers would actually check what kind of refrigerant was in the A/C! There is a small device that makes it easy to do. Drop-in replacements usually means you do not have to change the oil, service fittings or switches. R-134 is NOT a drop-in replacement but can be used. You have to change the oil, service fittings and you can lose up to 10% of the system capacity. Blended refrigerants can be used as drop-in replacements but as they leak you lose the proper proportions (different components of the mix leak at different rates) and that limits you to the # of "top-offs" you can do. You also do lose some capacity depending on what you are actually using. I use R-414. Seems to work OK, like using R-12. There is no good reason to not use R-12. You do not need a lot and it is not THAT expensive. You can still get it at places like E-Bay.
David Teitelbaum

[DMCMW Dave]

[QUOTE=NightFlyer;113426]

Personally, I believe the concerns about potential explosive flammability from the use of such a refrigerant is highly/greatly exaggerated.

QUOTE]

I agree. I don't use them for all the other reasons mentioned (compatibility etc.) but I've heard that running straight HC (aka Propane) is/was pretty common by people running older RVs. When asked about the danger of the flammability, they just point at the two 30-lb cans strapped to the back bumper for the stove and heater.

There is also the issue of 10 gallons of gasoline in the car, which is immensely more dangerous than a few ounces of propane, but it doesn't bother anyone.

[NightFlyer]

While the first link indicates HC-12a is a drop in for R-12 systems, the second link indicates FrostyCool 12a is for retrofitted R-12 systems (twice). So either one of the links are wrong, or, they are not to be used for the same purpose. "Drop in" V/S "Retrofit".
See?

Again, HC-12a is a generic term, with the 'HC' simply meaning hydrocarbon. It's just an identifier, and doesn't signify anything more. Basically, the reason for the discrepancy in FrostyCool's advertising of their 12a cans is that the cans are designed for use with R-134a can taps and fittings, thus why they proclaim it as being for a "retrofit" system. But the actual refrigerant in the can is essentially the same as any other 12a hydrocarbon refrigerant.

Also, due to federal and state laws prohibiting the use of hydrocarbon refrigerants in automotive a/c systems, I don't believe that they can openly advertise it as a drop in replacement for r-12 systems. Thus, the discrepancy allows them to get around the utterly pointless/stupid nanny state laws against their product so that they're at least able to sell it, placing the burden of liability for illegal use of the product on the end user / consumer.

Those using 12a and other hydrocarbon based refrigerants properly report great success. Usually, those bad mouthing the products as not being as effective as a DuPont patented product have overfilled their system or have too many different kinds of refrigerants in their system causing their problems. Remember, if you're completely evacuating the system and refilling with 12a, you want to use the proper amount as recommended by the manufacturer of the product. So, if your system takes 36oz of R-134a, be certain that you're only using around 14.4oz of 12a for maximum system efficiency. Overfilling with 12a will lower efficiency and be hard on the compressor.

[NightFlyer]

There is no good reason to not use R-12. You do not need a lot and it is not THAT expensive. You can still get it at places like E-Bay.
David Teitelbaum

You're right about using R-12, R-414, or whatever else will work. However, even many eBay seller's won't sell R-12 to you anymore unless you can provide proof of having an EPA handling certificate. And while the EPA certificate test is online, open book, and fairly inexpensive, it still poses a major PITA just to be able to buy a product. It's little more than a money maker for the EPA and a deterrent against R-12 usage. It's not like the EPA goes around busting individual/personal users of R-12 that install it in their cars without a certificate.

Nothing more than yet another example of our federal government run amok! :banghead:

[NightFlyer]

There is this http://www.imcool.com/articles/aircondition/Porsche_928_Refrigerant_Fire.php

Interesting article. That 928 sounds like it was a disaster anyway, irregardless of the refrigerant igniting and causing an engine fire.

"However, a DuPont technical representative was quite specific when he said that pure (no oil or air) Suva® R-134a was nonflammable under these conditions; a spark from fan motor brushes would not ignite it. This was not necessarily the case with an oil-134a or air-134a mixture."

So, basically what they're saying here, is that R-134a also would have combusted, as when it escapes the system, it mixes with air, unless I'm missing something.

I've notice that CoolProfit$ Magazine often takes a biased anti auto HC refrigerant stance, and is constantly praising DuPont products to high heaven. Leads me to believe that they might be funded in part by DuPont.

If 12a and similar products didn't exist, I wonder how much more expensive R-134a would be...

One thing for certain is that our governments needs to quit trying to give DuPont a monopoly on the automotive refrigerant business!

[Ron]

Again, HC-12a is a generic term, with the 'HC' simply meaning hydrocarbon. It's just an identifier, and doesn't signify anything more. Basically, the reason for the discrepancy in FrostyCool's advertising of their 12a cans is that the cans are designed for use with R-134a can taps and fittings, thus why they proclaim it as being for a "retrofit" system. But the actual refrigerant in the can is essentially the same as any other 12a hydrocarbon refrigerant.
This may well be true, but not how it reads to me, as I said. And I could not find anything similar to what seems to be your logical opinion/conclusion. In fact, I just read it all again and it says, "FrostyCool 12a Replacement Refrigerant along with mineral oil are Incompatible with butyl rubber hoses". That covers a lot of R-12 systems running around (incompatible)! I suspect FrostyCool is a HC-12a based product but has other things in it making it this way, or, the first link is wrong about it being a drop in. It may be the best thing ever for other systems, including conversions. Dunno, don't care, it's not worth any added risk, the price difference, and certainly not having pressure data for individual vehicles/systems when it comes to diagnostics later! (Or going on about ;-)

[Ron]

Nix the political tidbits.

[NightFlyer]

Are stances on regulatory action really considered political? If they are, then how come the threads making fun of government/DMV weight listings on vehicle registrations weren't also warned against political statements? Or what about the threads making fun of state government vehicle safety and/or emissions inspections - again, no warning from mods.

And yet, it seems like every time I merely mimic what others appear to do on a regular basis without censure, I get warned or PM'd or lectured by the mods.

Sorry, but I'm honestly really confused here :headscratch:

Perhaps there should be a better definition of that which is considered 'political' as well as consistent across the board moderation of that rule, as then I'd be far less apt to apparently violate said rule...

[David T]

If you want to talk about safety, Freon was created by the Germans before WW II as a precursor for Phosgene gas. What that means is if you burn freon you get a deadly nerve gas. As if that isn't dangerous enough, escaping Freon (any condensed gas for that matter) , if it gets on the skin, causes frostbite. I agree the flammability problem may be overstated but it still exists. Even with Freon the oil is flammable. If you want to talk about a REALLY dangerous refrigerant what about Ammonia. It is outlawed in small residential units but is still in use in large commercial systems. It is highly toxic, flammable and very corrosive. When Freon was being promoted it was promoted as a "Safety Refrigerant". It was, compared to what was in common use at the time. Compared to the 20 or so gallons of gasoline in most cars, it would seem the flammability of a couple of pounds of refrigerant is a non-issue. From the government's point of view, obsoleting a product so you have to buy new is good for the economy. Look what just happened to televisions. It may be a little harder to get -12 but it is not difficult or all that expensive. If it ever gets to that point you can always suck some out of an old refrigerator or window unit.
David Teitelbaum

[NightFlyer]

This may well be true, but not how it reads to me, as I said. And I could not find anything similar to what seems to be your logical opinion/conclusion. In fact, I just read it all again and it says, "FrostyCool 12a Replacement Refrigerant along with mineral oil are Incompatible with butyl rubber hoses". That covers a lot of R-12 systems running around (incompatible)! I suspect FrostyCool is a HC-12a based product but has other things in it making it this way, or, the first link is wrong about it being a drop in. It may be the best thing ever for other systems, including conversions. Dunno, don't care, it's not worth any added risk, the price difference, and certainly not having pressure data for individual vehicles/systems when it comes to diagnostics later! (Or going on about ;-)

Not that it matters, but HC-12a is actually nothing more than a registered trade/product mark of OZ Technology, Inc.

http://www.oztechnologyinc.com/hc12a.html

If you compare the MSDS for HC-12a or other 12a products, you'll see that they're essentially the same, with little variation. The drop in statement came from a Wikipedia entry that claims to be specifically about HC-12a, but speaks about automotive hydrocarbon refrigerants in general terms, thus I wouldn't place too much stock in the technical/specific accuracy of the Wikipedia entry. I was merely using it to reference hydrocarbon refrigerants in general, as opposed to being specifically about OZ Technology Inc's blend of 12a. Remember 12a blends aren't patented, so while only OZ can call their product 'HC-12a,' other 12a products could and probably do contain the exact same blend of hydrocarbons.

[NightFlyer]

Look what just happened to televisions.

If you're referring to the switch from NTSC to ATSC, the government actually provided people with coupons for converter boxes. Thus, all it did for the economy at the time of implementation was to take US citizen's tax dollars and put them into the hands of foreign corporations/manufacturers. Not sure how that helped the US economy any...

[Ron]

Not that it matters, but HC-12a is actually nothing more than a registered trade/product mark of OZ Technology, Inc.

http://www.oztechnologyinc.com/hc12a.html

If you compare the MSDS for HC-12a or other 12a products, you'll see that they're essentially the same, with little variation. The drop in statement came from a Wikipedia entry that claims to be specifically about HC-12a, but speaks about automotive hydrocarbon refrigerants in general terms, thus I wouldn't place too much stock in the technical/specific accuracy of the Wikipedia entry. I was merely using it to reference hydrocarbon refrigerants in general, as opposed to being specifically about OZ Technology Inc's blend of 12a. Remember 12a blends aren't patented, so while only OZ can call their product 'HC-12a,' other 12a products could and probably do contain the exact same blend of hydrocarbons.OK. Now we are together. I was only saying be careful with the "good information" because at first look it appears they were exactly the same not essentially, which it seems we can agree on. IE The information in the second link has some "qualifying remarks" that raised concern for me WRT compatibility (in one direction). I can see trying it after a full flush with no mineral oil...or ester, because of delivery problems if 134a etc was a fair possibility in its future -- Blend = Bad.

[Ron]

Are stances on regulatory action really considered political? If they are, then how come the threads making fun of government/DMV weight listings on vehicle registrations weren't also warned against political statements? Or what about the threads making fun of state government vehicle safety and/or emissions inspections - again, no warning from mods.

And yet, it seems like every time I merely mimic what others appear to do on a regular basis without censure, I get warned or PM'd or lectured by the mods.

Sorry, but I'm honestly really confused here :headscratch:

Perhaps there should be a better definition of that which is considered 'political' as well as consistent across the board moderation of that rule, as then I'd be far less apt to apparently violate said rule...

PERIOD! (http://dmctalk.org/showthread.php?116-No-political-religion-posts-or-threads-PERIOD!)

EDIT(Sorry....fire call):
The posts/tibits remain because they are no big deal, although mostly OT and political (exercise in discretion).
View my post as preventive maintenance, if you will.
Consider- A tidbit her and there, and before I can answer you, a whole post on politics/safety (~ok too), and a reply. Most members know what will probably be next. History does.

Please PM your favorite moderator instead of further cluttering the thread with OT :smile:

[Jason]

There is no good reason to not use R-12. You do not need a lot and it is not THAT expensive. You can still get it at places like E-Bay.
David Teitelbaum

Other than the cost, there is the advantage that with a hydrocarbon refrigerant if you need to disassemble your AC system you can just vent the refrigerant to the air without harming the environment. Unfortunately because of the crazy way the law was written its not legal, but at least its within the spirit of the law as far as protecting the environment is concerned.

[kings1527]

So I finished up my write-up on rebuilding my AC and it's here:

http://delorean6575revisited.blogspot.com/2013/08/resurrecting-r12-ac-system-and.html

This is probably the most in depth post I've done on my car. I had a ton of help from lots of people on the forum and I'm much obliged. Again, I'm no AC expert but mthy results have been excellent and hopefully they'll stand the test of time. There was SO much with this and knew next to nothing about AC when I began, so think of this write-up as my 'notes' as I went along. That's how my blog developed; as notes to help me remember what I did. I'm a big believer in you have to know how something works in order to troubleshoot and fix it.

Within the write-up, I went over a little bit of everything.

- a little bit of theory
- components of the AC system and what they do
- evaporator installation
- condenser flushing
- Hervey split hose installation
- accumulator installation
- installing the orifice tube (ugh)
- new compressor installation
- o-ring installation
- filling with R12
- adjusting the LP switch
- upgrading the fan circuit breaker to a 30a

And probably more that I can't think of.

Again, I'm no expert so if there's something that's not correct or needs to be fixed, please let me know.

Enjoy!

[jangell]

That is an awesome write-up (I still haven't read all of it yet, but I'm getting there). I know my A/C is slowly leaking refrigerant, and while the A/C shop couldn't spot the dye we added to the system, they did notice oil on the pipes from the evaporator. I hadn't realized just how much of the car had to be dismantled to get the evaporator box out. I think I'll be following your diagnostic steps with the vacuum pump and other suggestions about using nitrogen and soapy water to track down leaks before I tear apart my dash.

Thanks!

-- Joe

[kings1527]

That is an awesome write-up (I still haven't read all of it yet, but I'm getting there). I know my A/C is slowly leaking refrigerant, and while the A/C shop couldn't spot the dye we added to the system, they did notice oil on the pipes from the evaporator. I hadn't realized just how much of the car had to be dismantled to get the evaporator box out. I think I'll be following your diagnostic steps with the vacuum pump and other suggestions about using nitrogen and soapy water to track down leaks before I tear apart my dash.

Thanks!

-- Joe

Thanks! I'm glad it's helping you along.

As far as detecting leaks go, pulling a vacuum works well for moderate to large leaks but sometimes it won't pick up very small leaks. If you don't find the leak with a vacuum, you might want to consider pressurizing your system with nitrogen and see if you can find it that way. Some people use compressed air and then listen for where it's leaking. Compressed air has moisture in it but if your system has been void for awhile, you should replace your accumulator anyways so it shouldn't matter. Otherwise, nitrogen might be a better choice. It seems like you're already up on all that.

You might also want to think about using a sniffer for an evaporator leak. Take the sniffer and run it at the center vents to see if you get a solid reading. Sniffers can give off false positives but just another tool to use.

If it comes down to it, replacing the evaporator isn't all that horrible of a job. It just takes time.

[jangell]

My leak takes about 3 months to evacuate the A/C system. The last time I filled it was the beginning of summer 2012, and it was empty by the fall. It's been empty since then. I don't know how large of a leak "three months to empty" is, but I can try pulling vacuum first, since I'll need a vacuum pump anyway.

I do have a dinky air compressor (a portable, light-duty unit maybe 2 gallon capacity); its pressure gauge goes up to 220 PSI, but that seems optimistic given other posts that suggested a max of 100 PSI from an air compressor. I'm pretty sure I'll be replacing the accumulator anyway, so if I can get away with just using compressed air and an R12-to-whatever-an-air-compressor-is adaptor and some soapy water, that would be great.

Since my system is already pretty much evacuated due to leaks, I'm not sure if a sniffer would find much, would it?

As for pulling out the evaporator box, at some point I plan on doing some kind of custom center console that includes replacing the HVAC vacuum actuators with electric servos as part of a computer control thing. Having to pull everything apart for the evap will just shift my timetable a bit.


Random idea: It occurred to me that nitrogen is smaller than the R134 molecule and is tested at higher pressures than the A/C system normally runs at. This implies that if I evacuate the system and replace the compressor with an R134 model, then (in theory) I should be able to run R134 without any modifications. This of course assumes that I could plug all the leaks without replacing half the system anyway. This is only a theory, and I've heard of others running R134 in otherwise unmodified R12 systems, which is why I was thinking this might work. That and it's a lot easier to get R134 than R12, although I did get a few hits for R12 on a Craigslist search. Even so, there is a local shop here that can do R12 if I leave them the car for the day, but I'd rather do it all myself if I can. Also, I'd have to find a place to rent a nitrogen canister...

Thanks again!

-- Joe

[Bitsyncmaster]

A 3 month leak would probably show up with a "soap" test if the leak was at a fitting. If your hose is deterated you will never detect the leak since it's spread over such a large surface area. Just use a little freon to pressure test the system (unless you plan to go into the AC bussness).

My 2 month one can leak turned out to be the short hose from the condensor to the accumulator. Don't know why that hose deteratated more so than the other hoses but it did. I used that old hose to flush my condensor again and I could see black film in the solvent.

[jangell]

A 3 month leak would probably show up with a "soap" test if the leak was at a fitting.

Good to know.


If your hose is deterated you will never detect the leak since it's spread over such a large surface area. Just use a little freon to pressure test the system (unless you plan to go into the AC bussness).

So, even with a 120 PSI nitrogen test the hose would be leaking so badly that you you wouldn't get the sudsing? How were you able to figure out that your hose was bad?

As for using a little freon, I guess you mean to get a can of R134 and see what leaks out? Makes sense; technically illegal to let it into the atmosphere, I guess, but it is safe stuff and it's easy to get.

Thanks!

-- Joe

[Bitsyncmaster]

So, even with a 120 PSI nitrogen test the hose would be leaking so badly that you you wouldn't get the sudsing? How were you able to figure out that your hose was bad?-- Joe

Was the last hose not replaced. So trial and error.