The A/C in my '93 E150 was converted to R134a back in 2008. I bought it 4 years ago and I'm kinda amazed it still works. In really hot temps it's a little deficient but not too bad once I'm cruising. It has both dash and a rear unit but the rear unit is inop.

Is 134a better than R12 as far as leaks go?

It doesn't have a sight glass and wonder what other owners have experienced with their converted systems.

 

I had a 1990 Lincoln TC that was converted to R134a and it worked great but the TC has a much smaller area to cool then in our vans.
My 88 E150 does not have a rear unit and it gets quite hot on the very rear of the van but my van has a lot of windows and black on the sides also.

As to leaking, this is what have read from studies that have been done. When you convert from R12 to R134a, you need to change all of the O-rings to HNBR, which Highly Saturated Nitrile Rubber or hydrogenated NBR. The molecules in R134a are smaller then R12 molecules and it was commonly thought that when converting from R12 to R134a, that the R134a would slowly seep through the hoses over time and you would need to recharge your system from time to time. The newer hoses used for R134a are a barrier hose and have a extra lining in them to stop the R134a from seeping through the hoses.

So I imagine many people had their systems converted and then had to go back to have their systems serviced and were told the same as mentioned above..
Well more then likely they had a leak in their system. Research has shown that the older non-bearer hoses used in R12 systems become saturated with the mineral oil that circulates within the system and it seals the hoses in effect creating its own barrier hose. So when you convert to R134a, there is no loss through the hoses unless there is a leak!

i rebuilt my AC system with all new parts in 2016 I believe and went back with R12. It has been working just fine since with no leaks since then.
Anna

 

When we bought our 1990 RV about 12 years ago the cab AC did not work. We had it fixed and switched to R134a. It was very cold to start off with, but quickly was not so cold. I have added refrigerant a couple of times over the last 12 years. It works well enough to keep the front cab cool in summer.

Steve

 

Thanks for the replies. That's interesting about the hoses. The shop who did the conversion must have done a pretty good job and used the correct O-rings. I'm just keeping my fingers crossed and hoping it hangs in there at least thru this summer. I'll probably sell it in the fall since I need a 3/4T to haul a trailer.