1992 B250 conversion with a 5.2 liter and rear air conditioning. I pulled in the driveway, hopped out and heard a hissing noise and could see vapor coming from near the right front wheel but from underneath the van.
I found a freon hose that is routed to the rear a/c system had burst and was spewing out my priceless R12 refrigerant!!!

I'm pretty sure I can find the hose to run from front to back, my question is...Is there an inexpensive way to convert it to R134? Do those conversion kits at the auto parts store really work? I talked to a local mechanic about converting another vehicle to R134 and he said to do it right costs about $300. The weather forcast for this week here in NC is 93 degrees all week......help.

Any advice is very much appreciated.

Geoff

 

$300 is actually a good price. I've seen R12 to R134a as high as $650. This includes labor in either case.

 

A lot of people will tell you how you have to change this and that when doing a conversion. I've done literally dozens of conversions, never replaced any of those items, and always ended up with ice cold air. The one important thing is to make sure you get out the R-12 system oil because it is not compatible with the R-134a system oil. That means blowing out all of the refrigerant lines and the compressor.

Afterwards, add the new PAG oil into the compressor, seal up the system, pull a real good vacuum, then charge it up with the R-134a...done!

 

A lot of people put R134a into air conditioning systems designed for freon but I would strongly recommend against it.

R134a will chemically liquefy the dessicant in your R12 dryer and the liquefied dessicant will be pumped throughout the A/C system. This will cause compressor failure.

It may take a few years for the chemical breakdown to occur but it will happen beyond a shadow of a doubt unless you perform the proper R134a retrofit which includes a new R134a dryer.

BEST solution is to use Autofrost (or equivalent) to replace your R12. It is compatible with the lubricating oil already in your system and it does not negatively affect your existing dryer.

 

Rusty93,

The Autofrost stuff looks like exactly what I need. Is it available in any auto parts store or only online?

Thanks for the info!!!

Geoff

 

I've never seen Autofrost in a store. Last time I used Autofrost was for my 88 VW Fox and I believe I bought it on eBay, but that was 10 years ago. If memory serves there is a company called Enviro-Safe that makes what you need; just be careful to read all of the seller's information before making a purchase.