vetter61

Want to change the r12 freon to r134 on my original A/C car. I am planning on getting my original drier rebuilt but have read you have to specify what freon you are planning on using. Is this correct/ necessary?

Brian VH McHale

Why are you changing over to 134A?

vetter61

Cost and availability. Seeing that I don't drive my car over a couple of hundred miles in the summer,the car just sits in the garage. Have owned the car since 1973 and have recharged the unit many times over the years due to inactivity. Have read many many articles regarding the changeover and don't see any major issues.

Brian VH McHale

Cost of R12 is reasonable and readily available.

vetter61

The A/C specialty shop in Connecticut where I live told me the cost is around $100 /lb and it is not available in cans like the old days.This shop has been in business over 50 years working on classic cars. If I remember correctly I think he told me the system holds almost 3#. Seeing that the system naturally leaks,more so when not used often I feel it would just be easier and less costly to be able to add freon when needed by myself. Yes, I have had the ceramic seal on the compressor changed a couple of times and also had the system leak checked multiple times through the years, either with dye or the new electronic detectors. Was told by everyone who looked at unit that this type of compressor is prone to normal leakage especially if not run often. I have run the A/C in winter months like recommended to lessen the leakage but don't remember to do it all the time.

mark6669

The only difference is the o-rings there is only a desiccant bag inside the drier.
Mark

Powershift

Agree that different o-rings are specified/used for R12 and R134a. The "green" o-rings are HNBR rubber and are good for both refrigerants. The old "black" NBR rubber o-rings were fine for R12 but are not so good for 134a, and will leak more.

Regarding desiccants, R12 used zeolite 4AXH-5 for many years. However, it would not work for 134a. The (newer) desiccant to use for R12 or R134a is XH7. It will work for both refrigerants and is compatible with both mineral oil and PAG oils. Nowadays, just about every (or all) driers sold or rebuilt will use the XH7.

Either buy a new drier or tell the rebuilder to use the R12 and R134a compatible desiccant……..which should be XH7.

Larry

vetter61

Where is the best place to get my original drier rebuilt

Powershift

Classic Auto Air in Florida, Old Air Products in Texas, or contact PaceCarJeff in Ebay Stores. He may or not rebuilt your core, but he will do an exchange for a similar unit. He is the one I use.

Just about all original driers look the same. Jeff has many that are already rebuilt on the shelf. I think he uses Classic Auto Air. He did at one time, but may now do the work himself. You can trust him.vv

Larry