QuestionQUESTION: I own a 98 Chevy Venture and recharged the AC myself last year using one of those Wal-Mart recharge kits. Dura-Cool was the coolant that I used. It worked fine for some time(about a year). This year it's running warm again. I checked the pressure on the unit and it seems fine. The compressor is working as well. I can't seem to figure out why the system isn't working with those two things being in check. Also, I spoke to another tech and he suggested adding a can of Red Tek 12a as the system may need to be topped up. Is there anything to worry about with mixing the two refrigerants?
ANSWER: Tim,
ABSOLUTELY. I do not recognize the name brand of this Red-Tek-12, but I do no the law. Mixing refrigerants is a violation of section 608 and section 609 of the EPA's Federal clean air act. Punishable by a fine of up to 32,500 dollars per incident per day, appearance in federal court, and for a certified technician, loss of certification. If this tech is recommending you do this he is first off telling you to break the law. Secondly, mixing the refrigerants inside your system can and will cause all types of problems in the future.
Now, if this red-tek 12 is just another brand name for R134a, again I have never heard of it, then you are ok to do this.
I do believe that the tech you spoke with is correct in saying that your charge is low. If you had to recharge it before, then it goes without saying that you have a leak in the system. I would recommend that you have this leak found and repaired or you will continue to need to do this, and over time it will beome necessary more and more frequently.
When you checked the pressure what was your reading? and how hot was it outside the vehicle. They go hand in hand. To give you a general idea of where you should be reading... if it is 90 degrees fahrenheit outside, your low side pressure should read right at 58 psig. If you are reading less then this, then absolutely you have a low charge and need to either have it repaired, or get it charged.
I hope I was of a little help, if I can do anything more in the future please do not hesitate to let me know. Thank you for the question.
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QUESTION: Hi David,
Thank you so much for the information. You were very helpful. I may just go for the Dura Cool stuff again after confirming that the pressure is low. Anyway, if you have the time the stuff that I have is on the following website: http://www.redtekstore.com/tech.htm. The stuff is called Red Tek 12a Hydrocarbon Refrigerant. Please tell me what you think of it as I have a can if the stuff and would take it back for a refund if it is no use to me. Thanks again.
Tim
ANSWER: Tim,
Thanks for the site. I checked it out and according to their claims it is completely compatible with R134a and the ester type oil you already have in the system. I also read the spec sheet on it and it seemed to be rather good. It had a latent heat value of almost double that of 134a, the boiling point is slightly lower, and the Mass charge size was 1/3 of that of 134a.
Personally, I have always been a firm believer in using straight refrigerant, I still buy the 30 pound cylinders of pure 134a and try to shy away from the "new and improved" because my daddy told me the same thing everyone else's did. If it sounds too good to be true...
But if what they claim is correct, then you should have no issues using it in your system. But if you ever take it into a service shop in the future, make certain that you tell them what you have in it, simply so they can re-adjust their thinking when they read your pressures. Yours may not read the same as regular 134 in the event of a malfunction, and if they are uninformed, they could misdiagnose the fault you brought it in for.
So, in summary, I wont use it... because of personal taste and habits, but there should be no problem you adding it to your system.
If you use it keep one thing in mind. I stated earlier that the mass charge size was 1/3 of 134a. That is saying that a system that uses 1 lb. of 134 to reach complete charge would only need to use 3.3 ounces of this stuff. So if you are not careful you can overcharge your system. I recommend you charge it until the air coming from your vents is blowing about 40 degrees less than your outside ambient temperature. (I say it this way because chances are you will not be using a set of actual gauges to charge it, you will have the auto parts store gauge that only connects to the low side) If you are using actual gauges then charge it to the same low side pressure that you would 134a and stop. If you already have refrigerant still in your system and you add this larger mass refrigerant on top of it, you may not need the entire can. Just something to keep in mind.
But again thank you for the question and thank you more for the learning experience. Anything more just let me know.
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QUESTION: I believe I owe you the thank you. Services like AllExperts and the people that made their knowledge available to the public are priceless to me. So thank you so much.
Sincerely,
Tim
AnswerTim,
You are more than welcome. Glad I could help. I sent this one out not to keep hitting you up, but because Allexperts.com disables our accounts if we leave questions go a certain amount of time without a reponse. And this counted as a question... so... I responded.
Good luck in everything and take care.
