[77 Canamman]

Originally Posted by MUSLCAH

Talked to my AC guy....to put R12 back in the 67 GTO.....225.00... ouch....but it's got to be done

If you shop around, the 14OZ cans are easily purchased for $20 each. I just redid my 1977 Trans Am's system, which has a stated capacity of 3.75 lbs, or 60oz, which is just over 4 cans. I figure I have around $90 in refrigerant, but the end result is 36 degree vent temps, and a system that works as designed!

[DOC]

Not debating which is better, This is what I do/did since I am not licensed to use R12 and it is pretty easy to do. I Just converted a car to 134 for a friend a few weeks ago. This was the cost of materials and this was using the original A6 compressor in a 78 Olds Cutlass.

R134:- $26. Walmart
Dryer: :$18 Ebay
PAG oil: $ 9. Advance
orifice Valve: $3. Advance
Conversion kit: $11. Advance
Solvent to clean system prior to pulling a vacuum: maybe $5. I buy it by the gallon and used about a quart.

Temps at the vent on 82 degree day was 46ish. Takes a few minutes to cool down the cabin because the fan just does not push a great amount of air compared to a new car but still made the car nice and cool.

[MUSLCAH]

Last year with a 134 charge...in a 95 degree shop...the vents were 47 degrees at an idle...not bad for the 67 GTO

[4dblnkldude]

Why would you spend money making a system R-12 when it is gone. Theres a reason why tons of it is at swap meets.

[android 211]

If you have to sit in traffic with the a/c on - R12 hands down.
If your driving will be mostly highway, much less difference.

[Blued and Painted]

Toyota made only three change when switching from r-12 too 134.
Changed refrigerant oil and the junction O-rings. Added more window tint to reduce heat load.

The major components remained the same.

--

[Bruce Meyer]

R-12 works better in the old systems. Hands down. Whatever you decide on make sure you use the proper oil. The two are not compatible.

[JUKEBOX]

R 12 is the best freon in the old cars to use. The system was designed for R12. When converting to 134a, people don't realise you need a bigger evaporator, and condenser to make it work efficiently. 134 will never give you what R12 does. Low cooling evap temps, Unless your car was Designed for 134a. As long as you don't have a leak fill it with R12. Simple to check before you ever add freon let the system sit their for and hour under a vacuum, If it holds vacuum you know the system is tight. I have r12 cans .some

[FULZGOLD]

I miss R-12.
My 78 was converted to 134. It will keep you from dying on a hot NC day, but that's about it. Still better than nothing.
R-12 if you can swing it!

[72projectbird]

R12 flat out works better in these older cars.

The additional cost of tracking down R12 cans is minimal. How often are you servicing your A/C for it to be a big deal? Spending a little more per can shouldn't bankrupt you.

[Trevor78]

A lot of bad advice and incorrect information in this thread.

[77 Canamman]

Originally Posted by Trevor78

A lot of bad advice and incorrect information in this thread.

Care to share what you believe is bad advice or incorrect info?

[nUcLeArEnVoY]

Originally Posted by Trevor78

A lot of bad advice and incorrect information in this thread.

Well, come on, then. Don't be shy. What wisdom do you have to share on this?

[ta6point6]

I have to admit I have not been in an older vehicle that had R12 but I did put 134 in my 79 Trans Am, works good. I dont know if R12 would keep car any cooler but I do know that whatever refrigerant you use it will not increase blower motor speed. In my opinion that is the real problem with older vehicles. The blower motors need to push out more cold air then they do. When I use my AC in TA on hot days the fan is on high always and that barely rates maybe a 2 or 3 on my more modern vehicles.

[77 Canamman]

The vent temps in both of my old Pontiacs with R12 is 36-38 degrees F. The biggest issue with 134 in the old stuff is the condenser design, and getting all of the old oil out before putting the 134 in. If you swap condensers, then the cooling should be comparable.