What do you guys do about your A/C hoses when converting to R134? I called around and no one in this area rebuilds them with barrier hose anymore. Will I lose a lot through the stock hoses?

 

My 93 was converted 3 or 4 years ago and i still have all stock hoses and havent had a problem...yet

 

I just read a day or so ago that the hoses were changed in 1987 and are compatible with R-134. You might want to verify that... Maybe it was "after 1987".

 

As Cliff said the hoses were changed in the later models, I thought it was from the early 90's (1991) but there should be no issues getting new barrier hoses made up that is all that is used now. The older rubber hoses are porous, R134A will tear into the rubber hoses and result in slow leaks and restriction/blockage of the orifice tube screen by bits of rubber.

Do not forget to change all the O rings with the green ones for R134A, lubricate the o rings with PAG oil and do not over tighten.
Replace the accumulator, orifice tube and drain all the mineral oil from the compressor. Add the correct amount of PAG oil to the compressor as per your shop manual ,turning the compressor as you go do not overfill with oil.
Evacuate the system check for leaks and charge with R134A by weight, you want no more than 80% of the R12 by weight..

Again check for leaks, if you do not have an electronic leak detector use some dishwashing liquid and some water. A hand spray bottle will be the way to go, spray over all connections and look for bubbles.

All that's left is go for a drive and enjoy
Done properly you should have cool reliable air for many years.

Here is the quantity in oil and gas for 84-87 Corvettes.
6 oz PAG oil.
2.75lb R12 means 2.1 to max 2.2lb R134A.