A/C Recharge

[AcuraTech]

So it finally started getting warm out here in MN. Flipped on the A/C in my car (92 Acura Legend) a couple weeks ago and I wasn't getting any cold air. Bummer.

I've had the car since 03, and the A/C always worked really well without repairs or recharging.

So I took a look at the system and saw that some of the o-rings were leaking. ALL of the freon had leaked out over the winter unknowingly. So I went ahead and replaced the o-rings with new ones and vacuumed the system out. But then I found out that our shop can of R-12 is empty, and they aren't getting a new one.

A couple people I know have fresh 30lb cylinders of R-12, but I didn't want to crack them open for a couple pounds of freon when they're worth more full.

I was talking to to my dad (appliance/refrigeration tech) about it and he pulls out a cylinder of "Hotshot" R-414b, which is a drop in replacement for R-12. So we got the gauges out and charged it up.

First impression? This stuff is COLD! Had to turn the temp gauge up because it was so cold after driving for a bit. I'm hoping that there aren't any additional leaks that I didn't see, because I'm thoroughly enjoying the icy A/C.

Just thought I would post this for anyone looking for an alternative to R-12 without retrofitting. Putting R-134a in a system with old mineral oil is asking for problems, and flushing out all the old oil is a major PITA.

Not sure on the availability of the R-414b to the average Joe, but it's still being made and thus cheaper and easier to get than R-12.
Website of the company that makes it:
Makers of r-414b

I'll post back in a month or so and let everyone know how it's holding up.

*BTW if you're going to fix an A/C system, especially R-12, don't be a redneck idiot and just let old refrigerant out into the atmosphere. Take the time to do it right by having old refrigerant properly recovered and then fixing the leak.*

 

[mpvue]

thanks for the info. SO many people think that 'recharging' an A/C is normal. I've told so many people that if the system doesn't work, you've got a leak. 'nah, it just needs to be recharged'.

 

[Tahoe4Life]

Originally Posted By: mpvue
thanks for the info. SO many people think that 'recharging' an A/C is normal. I've told so many people that if the system doesn't work, you've got a leak. 'nah, it just needs to be recharged'.


You most definitely will get a leak if you don't use it often enough..Every time you use the system it gets lubricated..In the winter months you should use it at least 2X a week for at least 20 minuites..

You should use the Mix setting in the winter so the compressor is kicking on during those months.

 

[BuickGN]

Originally Posted By: FORD4LIFE
Originally Posted By: mpvue
thanks for the info. SO many people think that 'recharging' an A/C is normal. I've told so many people that if the system doesn't work, you've got a leak. 'nah, it just needs to be recharged'.


You most definitely will get a leak if you don't use it often enough..Every time you use the system it gets lubricated..In the winter months you should use it at least 2X a week for at least 20 minuites..

You should use the Mix setting in the winter so the compressor is kicking on during those months.


Agreed but usually the defrost runs the AC compressor. I also think most of the general public thinks a recharge is normal and that a car "uses" refrigerant.

My TL has never put out as good as I thought it should. Finally had a friend evacuate and recharge after only 2 years and it works better than new. I guess mine was low from the factory. I wish I would've taken tmep readings before the charging but with the fan on high, engine at 1,200rpm on a 90+ degree day, the air coming out of the vents was 38-39 degrees. I think that's ok.

I asked about overcharging a little and he said overcharging can be worse than undercharging. He did put an extra 1/10lb in for me just to make me feel good. Apparently it was about 30% low but since it hasn't gotten any worse over the years I have to assume it came that way.

 

[Buffman]

I think the gf's car has a clogged accumulator or something. [censored] thing

 

[duaneb9729]

the hot shot isnt approved for automobile usage, if i recall correctly, because of some very very small percentage of propane in it, now that being said, i have used it in my cars and work trucks, with sucess. Being involved in the hvac industry, this refrigerant was developed for older R-12 coolers.

i have found it to work well in the early 134a cars

 

[mechtech2]

Ford says the average car loses about 7 ounces of refrigerant a year.

 

[onion]

Mechtech, let's say for the sake of discussion that an average automotive a/c system holds 2.25 pounds of refrigerant. That's 36 ounces. If your oft-quoted statistic from Ford was true... then that means that once your average vehicle is 3 years old, it'll have less than a pound of refrigerant left in the a/c system (i.e., not enough to function).

Now... has that been your experience? That the a/c system in your average car quits working after only three years?

Is it possible that your favorite a/c statistic is bull$hit?

I don't care if Ford says so. I don't care if Jesus Christ says so. It just ain't so.

 

[Chris142]

Originally Posted By: duaneb9729
the hot shot isnt approved for automobile usage


ya don't bring that car to me. I cant recycle it, add to it or vent it. Gotta send it packing.

 

[daman]

I would not be so qwick to use this...

this info from msds:
Material: CAS Number Typical Wt. %
Chlorodifluoromethane (HCFC-22) 75-45-6 50% ................(not good in a R12 system....causes all sorts of problems...esp with rubber lined hoses)
2-Chloro-1,1,1,2-tetrafluoroethane (HCFC-124) 2837-89-0 39%
1-Chloro-1,1-difluoroethane (HCFC-142b) 75-68-3 9.5%
Isobutane (HC-600a) 75-28-5 1.5% .......(carrier for mineral lube)
*Regulated as a Toxic Chemical under Section 313 of Title III of the Superfund Amendments and Reauthorization

When retro fitting.....if this is the desired path....simply use 134a...works good.....can be recycled ....used more than one...the stuff above...use only once....has to be charged as a liquid....not Diy'er friendly......simply question....WHY???
Oh, yes..it is not a drop in replacement for R12....some advertisements lead one to think this can be added in with existing R12....ahhh...so....not so....only refrigerant that can top off an r12 system is r12.....all others have a specific retro fitting procedure and require the complete removal of r12 and the use of dedicated service port fittings....

and......

Misleading Use of "Drop-in" to Describe Refrigerants

Many companies use the term "drop-in" to mean that a substitute refrigerant will perform identically to CFC-12, that no modifications need to be made to the system, and that the alternative can be used alone or mixed with CFC-12. However, EPA believes the term confuses and obscures several important regulatory and technical points. First, charging one refrigerant into a system before extracting the old refrigerant is a violation of the SNAP use conditions and is, therefore, illegal. Second, certain components may be required by law, such as hoses and compressor shutoff switches. If these components are not present, they must be installed. See the section below on use conditions for more information on these points. Third, it is impossible to test a refrigerant in the thousands of air conditioning systems in existence to demonstrate identical performance. In addition, system performance is strongly affected by outside temperature, humidity, driving conditions, etc., and it is impossible to ensure equal performance under all of these conditions. Finally, it is very difficult to demonstrate that system components will last as long as they would have if CFC-12 were used. For all of these reasons, EPA does not use the term "drop-in" to describe any alternative refrigerant.

Also, an AC shop probably won't even hook up their equipment to your car if it doesn't have an recyclable refrigerant such as R134a or R12.

 

[AcuraTech]

Good post, Daman.

A couple things I have to say, though.

1. The R-12 was completely removed by recovering and vacuuming with a dedicated A/C machine before adding the R-414b. It wasn't just "topped off". Not too worried about an A/C shop not working on, because I'm the only one that works on it.

2. Yes, the best thing to use in R-12 systems is R-12. But getting a hold of some just involved jumping through too many hoops.

3. I've heard conflicting arguments about whether this is a good fit for R-12 automotive systems. Without being a chemist, it's hard to say. The manufacturer of R-414b says it's fine. A number of people I've talked to have had good results with it. Not that that means anything, but it would be asking for a bad rap if putting it in R-12 systems caused "all sorts of problems."

4. I thought about retrofitting to 134a, but that never works as well. I didn't feel like flushing the whole system. That's another can of worms. Some say just put the 134a in and it'll work fine. I disagree.

5. It's blowing ice cold yesterday and today, and that's all I'm really looking for. If it holds up for this summer or longer, I'll be happy. So maybe the R-414b will only work for 5 years before the A/C system breaks whereas R-12 could have lasted for 10 years. But who knows if I'll even have the car that long?

Basically this whole post is just a largely non-scientific study of what happens, and I thought I would share for discussion purposes.

At least if beats putting propane in the system!

 

[Tosh]

The sceptic in me thinks the great results from the new R-414b are from comparing it against the system already too low on R-12?

 

[AcuraTech]

Originally Posted By: Tosh
The sceptic in me thinks the great results from the new R-414b are from comparing it against the system already too low on R-12?


No. Last summer the R-12 was fully charged without any leaks and it blew amazingly cold.

Over the winter one or more of the o-rings went bad and the refrigerant leaked out.

Using the r-414b I would have to say that it blows even COLDER than when it had r-12 in the system.

Keep in mind that I work in a shop, I'm not just a shadetree, so I'm on top of this. The old r-12 charge didn't leak, it lasted amazingly well for 4 summers (i bought the car in early 2004). I hooked up gauges every year when it got warm out, and the pressures were always spot on.

Finally this summer when it got warm out it didn't work. Upon closer inspection, o-rings were leaking.

Therefore, r-414b is (at least in the short term) the stuff. Minus the attainability/recycling issues, it works amazingly well. Long term results have yet to be seen.