507
New tar stuff would be good, but other methods of insulation would also work. You can wrap it with foam strip
insulation, or you can even spray Great Stuff around it and let it set up in a clump. You can carefully cut a piece of 1/2
pipe insulation (looks like a foam tube slit down one side) to fit, wrap it around and tape or strap it in place. Just make
sure that that little coil is as cold as the pipe (which is cold!), not as hot as the engine.
REFRIGERANT LEAKS: Michael Minglin says, “A possible solution is a refrigerant additive available from Cryo-
Chem Int’l at 1-800-237-4001. It is called Cryo-Silane and reportedly seals small refrigerant leaks, without clogging
the system. It is guaranteed to seal and hold for one year any a/c system that takes longer than six hours to leak down.
As I said I have not yet tried it, and it isn’t cheap, but this may be the answer to small hard to find leaks.
“On the matter of hard to find leaks, with the a/c service gauges hooked up it is impossible to find leaks in the service
ports or valves. If your mechanic cannot clearly show you the leak, have him disconnect his service gauges and check
the the service port valves before starting to change out expensive hoses and parts.”
HOSES -- BARRIER VS. NON-BARRIER: How do you tell what type hoses you have? With this author’s ’83, the
two low-pressure hoses were non-barrier and the high pressure vapor hose was barrier -- probably indicating earlier
service work. The two large non-barrier hoses had a cloth surface -- black, but reportedly red became standard later on.
Barrier hoses, on the other hand, seem to always have a smooth black rubber surface. It may say “Barrier” right on it,
too.
Barrier hoses are nearly always attached to the metal tubes with a crimped collar. The high pressure vapor hose on the
author’s ’83, however, was attached with worm screw clamps -- worm screw clamps with a tang hanging off the side
that positions the clamp properly over the barb within. These worked fine on my car, and reportedly work fine in
general.
My non-barrier vapor hoses did not have crimped connections, although other non-barrier hoses may have. If a hose
connection is crimped, the crimped collar is usually steel. My hoses had steel tubes with aluminum collars, and the
collars had a big hex on the outside. These collars were jammed up against a smaller hex on the tube itself. This whole
thing is a threaded hose connection.
The large aluminum collar has a very coarse left-hand thread on the inside that threads onto the outer surface of the
hose. In the small end of the aluminum collar there is a very fine right-hand thread that the steel tube screws into. The
end of the steel tube, the part you can’t see, has a long smooth taper followed by fine threads right up to the underside
of that small hex. The collar is threaded onto the outside of the hose while the pipe is threaded into the center, jamming
that taper into the ID of the hose and compressing it within the sleeve. Very secure; in fact, you’ll probably have
trouble getting it apart. You need to hold the hose itself and the pipe still (clamp the hose in a vice and use a wrench on
the small hex on the pipe) and turn the aluminum collar in the direction that should unscrew it off the end of the pipe.
This is the same direction that will unscrew it off the hose, so turning the collar in this direction will pull the tapered
end of the pipe out of the hose.
That all may have seemed like useful info, but it’s probably not. The R-12 hose these fittings were designed to work
with is no longer manufactured (although there are generic hoses that will work just as well, if you feel the need to
rebuild an R-12 hose). The barrier hose will not work with these threaded hose connections.
The fourth hose on my ’83, the small section of hose on the liquid line, was completely different from the other three in
all respects. It was a funny type of hose with an inner layer of what appeared to be plastic tubing, a layer of strong
cloth, and an outer surface of hard plastic. It was crimped onto fittings, but it was an unusual type of crimp, probably
proprietary. The barb is brazed onto the tubes, and the crimp ring was formed anchored to a groove in the barb so it’s
not removable. The part number for the entire hose assembly is CAC.5596. It is unknown whether this was a barrier
hose or not, but it didn’t really matter; by the time I looked at it, it was clearly in need of replacement.