help please. what A/C system have I got here?

[haycait911]

system in my '80 SC. recently bought a complete system from a pelican for some bits I needed. it was from an '80 SC as well, but totally different than mine. fortunately he is willing to take it back ( thanks lonewolf!). but I'm back to square one and don't even know what to look for. some pics of what I have. the fittings are different, instead of a flare it's an insert with an o-ring. the hoses are marked 'murray', which doesn't sound very german, and are marked R12. if anybody recognizes something please pipe up. thanks, Don.

ps. does anyone know the recommended sytem capacity for refridgerant?

[Barrpete]

That compressor looks like a Sanden.

[tcar]

Do you have a front condenser? Need to know that to figure amount of refrigerant (no 'd').

Converted from the original York compresser.

Wondering if those are barrier hoses...?

[scottb]

Originally Posted by Barrpete

That compressor looks like a Sanden.

+1

I "think" the SC came with flared fittings originally. My guess is that the compressor and hoses have been replaced. Given that the SC came with a York compressor and non-barrier hoses, you're WAY ahead with the Sanden and new barrier hoses.

Scott

[stevemfr]

This is going back a long way, but the compressor mount looks similar to the Diavia kits we used to install way back when. There was another 911 kit manufacturer as well, but I'm blanking on the name. That is, if it's not just the compressor converted from a York.

O-ring fittings are actually better than flare fittings and the AC hose manufacturer prob won't do much for you - but those parts are all generic. You're most likely not going to find parts anymore (I just googled - Diavia no belongs to Delphi Automotive), but the Diavia system was based on the original system, so if I was replacing parts, I'd be looking for OEM style parts. Try griffiths : http://www.griffiths.com/porsche/ac/911ac/

[dentist90]

The Bentley manual has a page with required amounts of oil and refrigerant required listed. My manual is for 84-89 so amounts may not be relevant. I'm sure someone will post a scan of the page with the data on it.

[Pazuzu]

Originally Posted by dentist90

The Bentley manual has a page with required amounts of oil and refrigerant required listed. My manual is for 84-89 so amounts may not be relevant. I'm sure someone will post a scan of the page with the data on it.

From the SC Bentley manual...

--------------------------------------------------------------------------
Total system capacity of R-12: 1350 grams (47 ounces)

Lubricating oil capacity:
Compressor 120 gram (2.0 ounce)
Evaporator 20 gram (1.6 ounces)
Condensers 20 grams (0.8 ounces)
Receiver/dryer 10 grams (0.4 ounces)
--------------------------------------------------------------------------

Now...I understand that those numbers don't really make sense...the conversions are NOT consistent...but that exact set of values was repeated 5 or 6 times in the AC section. Do with them as you will...


After doing the metric conversions, 1350 grams=47 ounces, 120 grams=4.2 ounces, 20 grams=0.7 ounces and 10 grams=3.5 ounces. Again...YMMV.

[dentist90]

The 84-89 manual has similar figures: 1350g (47 oz) of R12
Total oil: 120g (50 in compressor, 40 in evap, 20 in condensers and 10 in dryer.

The o-ring type fittings are an updated style. What parts are you in need of anyway? The typical things are expansion valve, receiver/dryer and replacement o-rings to start off. The real fun starts when you evacuate the system and try to locate leaks!

[haycait911]

sadly not barrier hoses. clearly marked R12. the only thing I really need is the line from rear condenser to front condenser. after talking to my mechanic he suggested a union to bridge where the hole was. system didn't leak under vacuum, but blew a hole when charged. the line had rubbed on the driver's lower control arm and weakened the hose. he also suggested charging with the over-the-counter refrigerant as the molecules are bigger and don't tend to leak out like R134. also runs at lower pressure. will charge this weekend and let you know how things work out. thanks for all the input guys. Don.

ps. I thought it looked funny with a 'D'.

[dentist90]

I replaced this line as well last year... it's a bugger to get it up and around the windshield washer reservoir in the fender! Turns out that a PO had repaired one of the fittings at the front condenser with JBWeld as well (leaked out after about 4 weeks), so I replaced that unit last fall as well. I've seen ads for R12a... what exactly is this stuff? It's supposed to be an environmentally friendly replacement for R12 and more efficient than 134a. I was considering using this as well when I attempt my next A/C recharge.

[Barrpete]

R-12a is a mix of propane & butane which is, of course, flammable. There are several threads on the pros & cons.

[dentist90]

I'm a bit surprised that a retail chain (Canadian Tire) is advertising this as a replacement. I guess it must meet with some gov't approval or it wouldn't be for sale for this use.

[tcar]

I just read a couple of threads (one by a 12a supplier) saying that 134a is also flammable, and at a lower temperature than 12a.

Not sure I believe it.

I still happily use R12.

[haycait911]

well , after patching the line with an insert made for a/c lines, and some crimp rings, I re-charged the system. used the mentioned R12A, Red Tek brand. my mechanic says that the conditions for flammability are practically impossible to create. he suggested using the R12A because R134 will leak out of older systems quickly. I'm tempted to stock up on this stuff before 'they' decide it's unsafe and take it off the shelves again. put in one can of oil and 3 cans of R12A. a quick test in the driveway showed a 23 degree differential between outside air and the duct air.!

works for me! thanks everyone, Don.