you seem like an expert. were the AC components interchangeable BOP from that era? Like, mounts are different of course, but compressors, dryers, etc. I have a bunch of cars with AC that will never be used. And is the pancake better or the long one
R4 compressors themselves are generally identical besides differences in coil clocking and possible manifold variances. Some coils are 9 o’clock and some are 12. That’s not the end of the world, though, to have to work around. You might have to lengthen the pigtail in some, but not all, cases. The original Delphi/Harrison compressors had some variances in suction/discharge port diameter, and some hoses had pilots while others didn’t. The new ones have a uniform manifold design and use different spacer seal combos to compensate for hose block differences.
@CorvairGeek can likely elaborate on this better. Correct hose blocks are part of making new hoses so that’s not a dealbreaker either. I believe the A6s utilize either a 2 or 10 o’clock coil clocking, but the suction/discharge sizes, not to mention the manifolds themselves are the same. I’ll admit to not knowing these like the R4s and V5s, though.
O-tubes are universal in terms of physical fit, you just have to decide which color you want to go with. GM white is what they came with, but I’ve switched to Ford blue as my personal practice, and I think
@yevgenievich has tried Ford red, Chrysler orange, or both? The color corresponds to orifice diameter. The logic behind going to the next size smaller (.072” white to .067” blue to .062” red and so on) is compensating for the thicc R12 condenser tubes that don’t work as efficiently with dissipating R134a’s heat and helping the system work better in non-highway settings. I think it does help. The old condensers are very flush friendly, though, which is important to me so I’m in no hurry to run out and buy parallel flow condensers for all my vehicles. O-tubes are a replacement item because the screens can get full of trash.
Accumulators are not super interchangeable parts (e.g. B Body has its own, G Body has its own, square body has its own, etc.), but you should make a habit of conceding that if an old accumulator is exposed to the atmosphere outside of a few minutes during installation, the desiccant is ruined, and you need to get a new one.
The R4 pancake is an inferior design to really anything out there. That’s not to say that an individual compressor can’t go for many miles and work quietly, it does happen, but their design makes them more prone to not do either. The new ones have been built only by Comp Works/Four Seasons for like 25 years so there’s that monopoly. The A6 is solid, effective, just outdated compared with how designs improved over time like with Sandens or the Delphi/Harrison V5 and V7. They’re more expensive to deal with and very heavy to do what they do, but I would be open to resealing one. Even an R4 that didn’t have a lot of miles might be a candidate for a reseal, but if it had more than 80K, I’d junk it if it puked around the shell. I think puking around the shaft seal is more of an A6 attribute, but they’ve since come out with a better than OEM shaft seal for those.