Upgrade AC System? 70 Dart

[dcdman67]

Hi all. I have a 70 Dart Swinger with a Slant Six and factory AC. I am going through the car right now to ensure my wife will have no issues using it as a daily driver. After it's tune up, the next project is to work on the AC as we just moved to the Southern California desert. AC is a must! Are there any articles or how to's on converting the system to take the newer style refrigerant? Any part numbers? Thanks in advance!

 

[TrailBeast]

You might be best off to swap out the entire system to one that is already R134 compatible.
The new refrigerant can easily kill an older system and waste the time and money put into it.
There will be people that tell you it can easily be swapped, and I have personally done some using the minimal requirements, (evacuation, shrader valves, lubricant and R134) but more often than not the system doesn't work as well or it kills the compressor.
Kind of like turbo charging a motor with 300,000 miles on it.

For a stable and reliable system it needs the system replaced with a compatible one, and charged by a professional.

 

[ValiantOne]

I did a 134 swap on my old r12 system. After upgrading the condensor to a parallel flow type, rebuilding the compressor (rv2 types are beasts with their own oil pumps, very stout) having new lines made, new receiver dryer it worked well, until the seal pack in the front of the compressor gave out. Kind of ticked me off that a new seal pack gave out after 2 seasons, (i think it was a cheapie aftermarket piece) but ah well, what ya gonna do? In my case it'll be a moot point when i put the 360 magnum engine in as Ill retain the sanden compressor on that engine.

I think the outfit is Classic A/C that makes a kit that a few members have used. They seem to have a good rep if you want to swap out the whole thing. If you go that way you'll have something built for the 134 and the condition of the whole system will be a known quantity.

 

[65 Dartman]

On my 65 Dart, the plan is to use a new 134 Sanden compressor mounted with a slant F Body mounting brackets, original underdash components and original condenser (both units cleaned and flushed), new 134 compatible hoses rebuilt by Classic Air to install to the original fittings on the drier, condenser and firewall. The drier has already been rebuilt and I have new 134-compatible O-Rings ready to install where needed. Hope it all works out!

 

[BillGrissom]

I wouldn't since R-134A is already being eliminated, and has been for years in Europe and Canada. I use HC refrigerant in all my vehicles now, even the 1996 and 2002 after compressor failures. But, read the supposed fears first and think for yourself. Some people imagine it can "explode", though that is un-technical and even a fire has not been recorded in millions of car's usage for decades. I use Duracool, but Enviro-safe and R-12 HC are others. Compatible w/ R-12 mineral oil, but I use better PAO 68 oil in all mine, since more efficient and doesn't absorb moisture.

I would keep using the RV-2 compressor since changing that in a slant is tough. My 64 slant came w/o AC and I didn't want the RV-2 beast. You can find a long post giving all options in this forum. I ended up making custom brackets for a Sanden, but still have the 78 Volare Sanden brackets if I ever change to power steering, and they would fit better in your wider engine bay than my 1964's. BTW, there isn't really such a thing as an "R-134A compressor". The only thing that varies is the oil fill they come with, and that can be flushed.

 

[RealWing]

I converted my stock '69 Cuda 340 to R134A with no problems, but you need to do several critical steps:
1. use AC flushing solution and air blast to completely flush the evaporator and condenser. It is best to remove the condenser from the car to do this (ie lay flat when you flush to ensure all the old R12 oil is removed)
2. Remove the compressor sump and clean out all the old oil.
3. Replace all O rings with R134A compatible ones
4. replace the expansion valve with one calibrated for R134a (Rock Auto)
5. Replace the drier with one designed for R134a
6. Add the correct amount of new R134a oil to compressor.
7. Evacuate and recharge (use about 75% of R12 charge specs)
Jim