Aftermarket A/C installation

(August 2008) I finished this installation in 2005, it's still working perfectly fine so I guess I can say it was a success and finish this page!

This isn't a complete how-to, it's a somewhat complicated job, but this should cover the high points of retrofitting a Vintage Air system into a 1963 Classic or similar car. The engine's a 1970 232ci six. I apologize for the poorly organized page. There are photos all bunched up at the bottom, without captions.

Let's just say I took the long route to getting the job done.

(I started off trying to mate modern parts (O-ring fittings, Sanden, etc) to a factory built-in evaporator. I don't want to further embarrass myself by detailing the mistakes, to save you the trouble -- the old stuff is all flare fittings, the new stuff all O-ring. Stick with one system. I did in fact manage to mate them, with real parts, but it was ugly; also the low (suction) side on all the new gear is #10 and the old stuff it's #8. Even so, it would probably have worked adequately well if, after I got it all together, tight and leak-free, I hadn't discovered that the 40-year-old expansion valve was bad. I abandoned this foolishness and bought a new, matching evap unit; an under-dash VintageAir that was designed to look old-timey (eg.1960's).)

Old vs. new

Unless you're doing a restoration, I most strenuously suggest a good aftermarket system like Vintage Air. Leave the old factory stuff for the restorers.

Believe me, I've done it both ways (or tried to). If it's a restoration OK, but 40+ years of development has gone into the new stuff, and believe me, you want that! It's like 6V generator vs. 12V alternator!

The bottom line on compressors is this: the old York style "lawmower engine" compressors are inefficient, large, heavy. The reason the got a bad rep (deserved) is that they are most efficient at low speeds -- eg. when idling and in-town. Right when your cooling system is least efficient. At higher speeds, like highway cruise, York-style compressors are less efficient. They are one or two-piston designs that consume lots of energy. They are all now very old and all need to be rebuilt, period, so they're not even cheaper.

The new Sanden type compressors are small, light, 7-piston designs, that are more efficient at higher speeds. They consume lots less power over all. There's a mount kit that adapts them to York mounting plates. They are common, available, repairable, new.

The old plumbing used flare fittings and even some clamp-type compression fittings. These are hard to make not leak (with good care they do work first time, but... not so good when they are old! hint hint)

The new fittings are all O-ring. They basically never leak. All the new stuff comes with O-rings.

There are old-timey-looking under-dash units. I have one in my 63 Classic. It fits fine. Wouldn't work with floor shift, probably. Check that.

h234a cools as well as r12 if you have a big condenser (in front of the radiator). Factory condensers are often "as small as we can get away with" for cost. Aftermarket ones are larger and not dented and fins all good and connections are not corroded and all O-ring.

There's nothing magical about R12. There are some issues back-converting old ssytems to h234a, but that's due to old seals and inefficient condensers.

There is essentially a "calibration" in the evaporator unit (inside the car) that is R12 or h234a specific. They're close enough to be "close enough" if you have a good clean system and conver R12 to 134. THIS! is where people complain that the new stuff isn't as good as the old -- in marginal old systems designed for R12.

Last, alas, it's simply not cheap. I tried to use a factory under-dash system, it was a major PITA, and then in the end the expansion valve was bad, and would have cost too much to re-cal for h234, I bit the bullet and spent the $250 (in 2004?) for the under dash unit. Compressor was around $250, condenser $100? $150? dryer, hoses, blah blah.


In the abstract, the installation consists of mounting the major components, evaporator (inside the car), condenser (in front of the radiator), and compressor on the motor. The rest is custom work connecting all the parts. The hoses are a big deal.

I couldn't find compressor brackets to fit my engine (pre-1972 AMC 232) so I modified a 1980's bracket I found in a 'yard. It would mount an alternator in the newer position too, but I didn't use that. The bracket attached to the block via three tapped bosses on the left; some time after my engine was made the bottom boss was repositioned. I had to lop off the bottom of the bracket, and re-drill the hole. I did it on a small mill, but it could easily be done with a hacksaw and file.

The condenser was fairly easy; I simply measured and bought the largest one that would fit, from Vintage Air. The condenser is the single most important part, don't get a cheap one. I punched a hole in the radiator surround to pass the high-side hose from the compressor, it was simply the easiest way. The condenser comes with a mount kit, it screws onto the radiator brackets. I took the grille and bumper off, it made life a lot easier.

Figuring out how to put the drive V-belt on was a pain, but easy to reproduce. There's a belt idler/tensioner that you get from an 80's car that bolts onto the front two head bolts. Sigh, you gotta pull the fron thead bolt out to install one with a stud end. Get that from the donor. See photos.

The crank pulley will probably have only one groove. There are simple bolt-on accessory pulleys that attach to the harmonic balancer with three 5/16-18 bolts. Yo ucan find them on many late-model AMC or Jeep donors.

The belt doesn't clear the upper radiator hose. So I found a new hose that looks like a ? and clears fine. It's worked great for 3 years now. I think I used Gates/NAPA 7717. You may need to chop one end shorter.

The under dash unit was quite easy to mount, comes with instructions, and is no big deal.


A/C hoses are a Real Big Deal. Pressures are very high, and if you want the freon to stay INSIDE, you need zero (0) leaks. The hose is somewhat pricey, but not too terrible, and the fittings are cheap enough. The crimp tool is very expensive, like $450. Half way through this job I found my father had one and borrowed it, but here's how to do it without owning one.

Mount the big items, then route the hose. Factories take the shortest straight-line path because they are penny-pinching. Save yourself future grief by ruouting hoses around things, around the fenders and firewall. Though they could pick up some heat along the way (1) you can very cheaply buy hose insulation and (2) that is offset by the ability to be able to actually work on your car after it's installed.

The fittings are barbed, so once you press them on it's a pain to get them out! So initially just press them in 1/4" or so. When every hose is in place and cut to length, press them in all the way, and rotate the fittings properly. Once crimped, you CANNOT twist A/C hose; it's reinforced, and when pressure is applied they will stress and leak. If you can screw/unscrew the fittings by hand it's fine.

Then carefully take all the hoses out, use a paint pen to mark the hose and fitting position, and take them all to a hose shop for crimping.

I forget what these pictures are for. News at 11.