R-12 conversion to R134 ... BTDT? Any regrets? Recommendations?

[Joshua Van Tol]

>Fred,
>The far SUPERIOR METHOD for finding leaks is using a sniffer, ABSULUTLY not
>dye!
>The main reason we (the industry as a whole) is using a dye is because
>technicians do not like, and do not maintain the sensitive leak detector
>equipment well!
>I can't even begin to tell you how many time I had to assist dealers in
>finding leaks WITH A LEAK DETECTOR!
>
>Another piece of information that might entertain you...........you could
>have a rather large leak that will show no dye evidence!
>
>All the dye is a flu recent oil coloring, so if it leaks oil you will see
>the dye, if it does not leak oil just fine vapors you will not see it!
>
>As for your repair people they were either using a bad leak detector or
>extremely incompetent!
>
>You all take care now...........
>Avi

I agree with Avi. You need to know how to use a leak detector 
properly, but when used correctly (and when it's a quality piece of 
equipment) leaks of 1/2 oz per year can be found pretty easily. The 
key is to move slowly, along the underside of hoses, fittings, etc. 
Suspect spots are the compressor shaft seal, all fittings, 
evaporators, condensors, etc. A neat trick that works for finding 
evap leaks, which are hard to find because the evap is so inacessable 
is to run the ac for a few minutes to get the pressure up, shut it 
down, and wait. Then, put the leak detector near the drain hose, and 
see if you get any blips. If not, try turning on the fan on low to 
force some air through. You can also put the detector in the air 
vents and turn on the fan. Not quite as foolproof as looking at the 
drain tube, but easier. Other things to watch out for is sensor 
contamination, and cheap leak detectors. I've had good luck with TIF 
branded detectors, in the $200-$350 range. Cheaper than $200 and it's 
probably junk. Look for something that can detect a 1/2 ounce or 
smaller leak per year.
-- 
Joshua Van Tol -- josh at spiny.com