A/C restoration

[treed2@u.washington.edu (T. Reed)]

Craig,

The advice I'd give you is make sure you do it right especially if you
want it to last. Mine worked great for 4 weeks before plugging up and
exploding in a dramatic 1 minute long disneyland-like show of escaping
refrigerant vapor, and coating my engine bay with refrigerant oil. It was
pretty cool to watch, but expensive (the retrofit to r134a cost me $50 and
the drier was another $20 or so). Fortunately, I live in Seattle where
it's freezing 348 days a year so the a/c was merely a toy I could do
without.

The method I used was pull a vacuum, replace the drier, install r134a
conversion kit from an auto parts store, charge with 22 oz r134a, ester
oil, and leak sealer. My diagnosis for failure was that the expansion
valve plugged and the pressure switches failed causing the 300 psi plug
in the drier to blow and drop my refrigerant charge.

I would highly recommend replacing your drier and expansion valve. Or at
least remove the expansion valve and make sure it isn't going to plug up.

Also, I would take it to an a/c shop and have them blow nitrogen through
the lines to make sure any old oil or broken up dessicant is gone and
won't accumulate, plugging the expansion valve later on.

Get your pressure switches checked if you're going to charge with R-12 or
some other expensive refrigerant. If they work, you -won't- blow your
refrigerant charge if something plugs up. Instead, the compressor will
just cycle off.. which is a lot cheaper (I would have had to buy a new
drier as well as refrigerant because the plug only blows out once)

HTH,

-Toby