The Stovebolt Site Forums The Shop Area Interiors A/C in 58 apache 31 fleetside

does anybody know anything about a MARK IV air cioditioner. as long as i can remember the truck has had it in there. it was mounted under the center of the dash with hoses that ran out thru the firewall to the compressor. was this a factory opption, or was it just something added by a local mechanic? if it matters my truck has the thriftmaster 235 engine in it. also can you rebuild one of these A/C units and is it worth it?

Cowboy - there was optional AC available in the cars then, but not the trucks - that's no doubt an old 'retrofit', possibly using the car stuff, but there's always been '3rd party' units available - hafta check into wether it's worth rebuilding w/ someone local, re the freon situation - illegal now, and can't be mixed w/ the new stuff, so requires purging the system completely, and the newer version may not work in yer old unit

Bill

cool red thanks...

Sounds like an aftermarket unit. R12 is not illegal, just highly regulated and therefore very expensive. In my experience, R134a is just as good, and the conversion is easy.

the unit i assume is mounted underdash. it's aftermarket, but if it's pretty old then it's quality built. no need to rebuild it. it's a coil, a blower, and a txv (expansion valve). a good cleaning (outside) helps the effeciency. NOTHING--AND I MEAN NOTHING needs to be cleaned on the inside, unless there's been a total breakdown of the compressor, or the dessicant charge in the receiver drier has ruptured (rare).

there's a drop in oil that's compatable with r-12 and r-134, so you can do the refit. you can find alot of techs that have the certification for r-12 to do the recharge if ya want to keep it totally original. r-134 isn't as cold as r-12, and the unit will take longer to start cooling down. most people don't notice the difference, unless they live in a real warm climate.

have somebody do this who knows what they are doing. it doesn't have to be a dealer, but if ya overcharge the system it makes a real expensive noise. then it don't cool at all. private e-mail me if ya think i can help.

why does yathink he calls hisself koolkar?

Koolkar, I did the 'real expensive noise' thing. Twice. In the same car. With a nearly inacessible compressor mount. I've become fairly decent at A/C work since then.

thanks koolkar... i'll let you know

Make sure you have good hoses still, They don't last forever. I used to work in a A/C shop that did aftermarket installs and custom stuff for hot rods and we had machines and tools to redo A/C lines and hoses. You would be surprised how many we did in a day for outsiders. I would change them anyway if I was going to use R12, just because the stuff is expensive. I'm thinking you probably have a orfice tube type of system not a TXV type as someone else suggested, I would check it if you indeed have that system. TXV systems are fairly new I doubt they were using them back then, Alot of Domestic's use the orfice still on new models. Just some thoughts....rue