Pandora's Box is actually A/C system refurbishment

"Chairman Kaga" (mike-mckinnon) 07/14/2014 at 11:33 • Filed to: None

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I've finally decided enough is enough, I'm going to get my GTV6's AC up and running. Starting with the basics, I'm replacing the original and long-ago seized York compressor with a newly rebuilt Sanden 507, which was actually an upgraded component used in the later Milano/75. I'm tracking down some Milano brackets, which will bolt right up to my engine block (it's the same 2.5L V6).

I also ordered a new receiver/drier from a mid-80s Saab 900. Exact fit for 1/3 the price of an "official" Alfa part.

Since I'm switching from freon to R134a, I have to replace all of the o-rings, which I should probably do anyway since the system has been sitting with no refrigerant or pressure for who knows how long. The hoses seem to be OK, but I won't know until I get the original setup under vacuum. If no leaks, then I can assume I can swap in the new parts, get it under vacuum again, then trundle over to the AC shop for a recharge.

Except some of the more pedantic car guys insist I have to flush the entire system repeatedly, replace all of the hoses, the expansion valve, and various other bits. Really?

I'm also replacing the condenser with a modern parallel flow unit, but I can't determine exactly what size I need until I drain the coolant and remove the radiator, which is a 15-step process that likely also involves removing the exhaust manifold. Probably time for that anyway.

If I'm going to that much trouble,, I should probably remove the dash and pull the evaporator and heater core and thoroughly clean out the box and fins because who KNOWS what's in there.

Even after all of that, the stock system is about as effective as "an asthmatic mouse blowing through a straw."

I can add a second evaporator/blower, which was actually a stock upgrade for American market cars because the AC was so pitiful. I know a guy who has one for $140. It requires adding two t-junction fittings, and since I don't have a beadlock crimper, a trip to the AC shop to have that work done. So $180-190 total for that option.

I could also upgrade the main blower fan and reroute some of the air to the fresh-air vents. I'll be blocking them anyway to prevent more leaves and debris from collecting in the evaporator (by the way, that was a great design feature, Alfa).

A final option would be to blow $400 on a Vintage Air MiniGenII system, which would replace my entire stock evaporator/heater core/blower. It's supposed to fit in the original box, and the original controls can also be adapted to the VA unit's electronic controls.

Ugh.

Maybe I should just be hot.

RamblinRover Luxury-Yacht > Chairman Kaga 07/14/2014 at 11:36

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No way to revive the York? Oh well. Somewhat tragic, as those things tend to be amazing in capacity. I guess from the rest of the post the evap/condenser you have a little weak, though, and Sandens are pretty solid in other applications I remember.

You probably ought to flush at least once, but don't kill yourself unless you have reason to believe there's been moisture living in the lines. Since Texas, probably not.

Chairman Kaga > RamblinRover Luxury-Yacht 07/14/2014 at 12:10

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One guy recommended I just blow it out with compressed air, but I've never used an air compressor that didn't eject rather copious quantities of water, unless there's a specific type for AC use. If I go to that kind of effort, why not go ahead and flush it? I wonder though if I shouldn't flush the evaporator in case there's old crud in the tubes, since I have to disconnect the hoses to replace o-rings anyway.

The York compressor on this car was sort of a disaster. It's a boat anchor for one thing, but the vibration actually damages the aluminum block if you run it a lot. The engine wasn't designed for AC, and was basically retrofitted in the States due to demand. Alfa switched to the Sanden ASAP. I might try to fix mine and use it as an air compressor. I also hear Jeep guys love them for that reason. They'll rig up a system on rock crawlers to inflate tires.

RamblinRover Luxury-Yacht > Chairman Kaga 07/14/2014 at 12:18

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Flushing the evap is probably a good idea, since doing it at this point makes for the best access.

As to disastrous "factory retrofit" A/C mounting, first-gen VW Golf/Rabbits are very hit and miss. There are some better arrangements out there for different sub-models, but mine (diesel) had the A/C compressor mounted at maximum distance from the crank on a long vibrating moment arm. It gave me fits with working loose and rattling the alternator loose with it. I eventually had to do a wholesale replacement of fasteners with loctite.

The R12-filled York-powered system in my dad's W115 Benz used to blow ice crystals through the vents on a humid day. High 80s outside, sub-30 A/C.

Chairman Kaga > RamblinRover Luxury-Yacht 07/14/2014 at 12:44

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I'd stick with R12 if I was absolutely confident there were no leaks in the system... I know a guy who knows a guy.

I had an '83 Rabbit diesel in college, by the way. The AC never worked and every estimate to fix it was ridiculous... Now I know why.

RamblinRover Luxury-Yacht > Chairman Kaga 07/14/2014 at 12:46

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Mine typically worked, except when working loose, or for a short period after I took a rock through the grill to the condenser.