A/c

[id_soso]

My 78 just lost the Freon using the r-12. Is it better to fix or change to r-134. I live in the desert and the car is black and I mean really gets hot in the summer. Need all the cooling I can get.
Secondly the temp stays at 200 until the air comes on. I put a dam underneath but still gets hot. I had the radiator cleaned flushed and refilled any ideas?

 

[jon79flavette]

ID: Why I am not a automotive A?C expert, I am a A/C contractor for commerical and residential, and refrigeration. R-134-A is not going to cool (pound for pound if you will) as well as the outdated R-12, plain and simple. There are some fairly complex explanations for this, R-134-A is non-clorine based, hence the the enviormental issues, boiling points, syntheic oils etc. The major problem (aside from it being technically illegal to have a r-12 auto charged after 1993??) is the freon cost. We used to pay approx. 30 to 35 dollars for a 30 gal. "jug" of 12. It's now about 700 bucks. There is actully a black market out there with r-12. Bottom line is r-12 is superrior for coling and TD's, but will be cost prohibitve unless you have some connections. r-12 compressors are NOW easily converted to 134-a at very minimal cost. We will face the same issues very shortly with residential/commercial A/C as R-22 is giving way to R-410-a. Any (a) at the end of cooling denotes a non-clorine based refrigerent, and presures are much higher, at times double. Which is never good. Your hands are some-what tied, as the r-134-a. it would be your best choice IMHO, thank our goverment mandates on that! Jon

 

[Bob Chadwick]

What Jon said is 100% accurate. The cost is the issue.

I converted mine to r-134 and get 38 - 40 degrees blowing out the vents. My real problem is insulation. The heat from the floor boards makes the car get cool but never that freeze your a*s off feel. Once I get this insulated I expect to correct this.

My Acura Legend will freeze you out of the car on the hottest most humid days in Atlanta and it is and always has been R-134.

Bob

 

[jon79flavette]

I hope I am not too long-winded here, but you posted ("my 78 just lost it's freon") My experience is that most A/C systems, car or others, are sealed, closed loop systems if you will. They very seldom would just have a sudden discharge of refrigerent. Before charging or retrofitting to r-134-a (very easy if you don't properly reclaim, nobody does, but there is the legal issue again) dumping gas in to fix the problem is often not the problem. Leak in the evap coil, hi and lo presure hoses'fittings, punture, road debris, cracked welds on the accumulator etc. a very slow diminishment of freon can occur, where you can "bump-it" to get by for a while, but suuden loss most likely points at a more fundemenal problem.

 

[page62]

I got my AC system professionally rebuilt -- at great expense -- using R12. But if properly done, as mine was, the system will last for years.

And yes, it can get freezing cold in our car in 95+ degree heat...even with glass tops! It's got the coldest AC of all our vehicles.

 

[DDLS3]

id,

Well over a year ago a refridgeration tech installed R-401B in my 81 which had been previously R-12. It did not require any equipment change and it only cost me $70. R-12 is well over that per pound these days and the system holds over 3 pounds, plus the fact that it is illegal to refill a leaking system. R-401A and B is not well known to the automotive side, but is used extensively in heavy earth moving equipment. I get 38 degrees blowing out the vents on the hottest days. There are options to converting to 134.

 

[Tom73]

My 78 just lost the Freon using the r-12. Is it better to fix or change to r-134.

No matter what you use, you will first need to get the system fixed. Apparently there is a leak somewhere. Find and repair that before you do anything else. But, me, I would go for the R12.

tom...

 

[mga]

try using some stuff called "enviro-safe" sold by autorefrigerants. simply evacuate what you have in there now and add this stuff. it puts r-134 to shame and will give r-12 a run for it's money. no need to change hoses, "o"rings or seals. i use it in my '81 and i have no complaints.

 

[id_soso]

Thanks to all who replied. And the answer to all the questions is the system did have a leak. I ws able to find a mechanic that found it and re-charged it at a very reasonable price.