Author Topic: 74 fleetwood AC  (Read 477 times)

Offline ithaca1230

  • 1974 Fleetwood
  • Posts: 42
  • Name: william epthimiatos
74 fleetwood AC
« on: June 15, 2017, 08:18:52 AM »
was gonna get into the AC next on this thing and was wondering if any of you have converted over to the 134a stuff. I was told you should put less than the original stuff. Any advice is appreciated.

Billy

Offline Dan LeBlanc

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Re: 74 fleetwood AC
« Reply #1 on: June 15, 2017, 09:07:16 AM »
In my opinion, keep it running on R-12.  There's still tons of it out there and, although more expensive, performs better.
Dan LeBlanc - CLC # 27657
1970 DeVille Convertible
1953 Series 62 Sedan (Parts Car)
1953 Fleetwood (Project Car)
2004 Deville

Offline Eric DeVirgilis CLC# 8621

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Re: 74 fleetwood AC
« Reply #2 on: June 15, 2017, 09:17:31 AM »
Second that advice.
A Cadillac Motorcar is a Possession for Which There is no Acceptable Substitute

Offline "Cadillac Kid" Greg Surfas 15364

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Re: 74 fleetwood AC
« Reply #3 on: June 15, 2017, 09:33:36 AM »
Billy,
If your system is functional and is still charged with R-12, by all means you will have no advantage (costs for R-134a are about to skyrocket) in "converting" and disabling some of the R-12 system functions such as continuous humidity control.  The capacity loss using R-134a (vs R-12) is about 21%.  That said, in your location AND if there are not to be extended jaunts in heavy traffic The reduction in capacity will have minimal effect with your outside summer design temperatures below 90 degrees.
First of all there were two systems in use in '74. Early systems used an external expansion valve and later systems used the first generation (and troublesome) VIR. 
Which system do you have and why are you considering changing?
Greg Surfas
Cadillac Kid-Greg Surfas
CLC #15364
66 Coupe deVille (now gone to the UK)
72 Eldo Cpe  (now cruising the sands in Quatar)
73 Coupe deVille
75 Coupe deElegance
76 Coupe deVille
79 Coupe de ville with "Paris" (pick up) option and 472 motor
514 inch motor now in '73-

Offline ithaca1230

  • 1974 Fleetwood
  • Posts: 42
  • Name: william epthimiatos
Re: 74 fleetwood AC
« Reply #4 on: June 15, 2017, 09:55:10 AM »
The AC is not working currently. It appears that the thermostat is operating (we tested it) just no cold air. I went around trying to find some of the R-12 and no one around here has any. I was told to convert it over to the R-134a. I am not sure if I have the early or later system. maybe you can help me identify what I have. Is there a source for the R-12? I would not convert if I didnt have too.

Offline "Cadillac Kid" Greg Surfas 15364

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Re: 74 fleetwood AC
« Reply #5 on: June 15, 2017, 09:57:38 AM »
A picture (of the engine compartment side of the ac/heater box and accessories iof the refrigeration system) is worth 1000 words.
Greg Surfas
Cadillac Kid-Greg Surfas
CLC #15364
66 Coupe deVille (now gone to the UK)
72 Eldo Cpe  (now cruising the sands in Quatar)
73 Coupe deVille
75 Coupe deElegance
76 Coupe deVille
79 Coupe de ville with "Paris" (pick up) option and 472 motor
514 inch motor now in '73-

Offline ithaca1230

  • 1974 Fleetwood
  • Posts: 42
  • Name: william epthimiatos
Re: 74 fleetwood AC
« Reply #6 on: June 15, 2017, 10:04:42 AM »
Greg is there a "how too" on posting pictures. I have not figure out how yet. Thanks

Billy

Offline Dan LeBlanc

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Re: 74 fleetwood AC
« Reply #7 on: June 15, 2017, 10:25:53 AM »
There's tons of R12 on ebay for about 25-35 for a 12 oz can.  You'll need about 5.3 12oz cans.
Dan LeBlanc - CLC # 27657
1970 DeVille Convertible
1953 Series 62 Sedan (Parts Car)
1953 Fleetwood (Project Car)
2004 Deville

Offline Scot Minesinger

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Re: 74 fleetwood AC
« Reply #8 on: June 15, 2017, 10:53:43 AM »
If it was me, probably would buy a can or two of r12 and add it in to see if it keeps you cool.  If not, you have a decision to make.

The r134 works really well on the 1971 and newer Cadillacs due to larger condensers and blowers.  The 1970 and older, not as well.  The most common failure of a 1974 - 1976 is a leaking VIR (that canister on pass side with five refrigeration connections).  That probably needs to be re-built (rebuilt ones are sold on the internet all day long).  However, I have found that the ffailure rate of VIR's are about 25%, and you know how that goes - first time probably have an issue.

The r-12 works better no question, but no one has ever complained about r134, except in the 1970 and older Cadillac 134 conversions.  The r134 is more readily available from a service perspective and that is what I use.  You need a way to recover the refrigerant if there is a problem besides a leak (such as VIR, or a slow leak) so you can work on the system.  I do not know anyone who has the ability to recover r12.  So if it were me, I would buy r134 and use that.

To properly convert to r134, you need to flush the system and change the hoses. 

However, if r134 becomes like r12 in the future, I think I will probably buy an r1 devoted machine and go with r12 from now on.  That day has not arrived yet and the devoted machine is $4,000, so will wait for it.
Fairfax Station, VA  22039 (Washington DC Sub)
1970 Cadillac DeVille Convertible
1970 Cadillac Sedan DeVille
1970 four door Convertible w/Cadillac Warranty

Offline "Cadillac Kid" Greg Surfas 15364

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Re: 74 fleetwood AC
« Reply #9 on: June 15, 2017, 11:07:05 AM »
Billy,
Take a digital picture and file it in "My Pictures" on your computer.  Then resize the picture to (I believe the max is) 750 Kbts. When you post a response, go down to the "Attachments", click on that , go to the photo you want to post and click on that. You then have included the picture in your response.
Greg Surfas
Cadillac Kid-Greg Surfas
CLC #15364
66 Coupe deVille (now gone to the UK)
72 Eldo Cpe  (now cruising the sands in Quatar)
73 Coupe deVille
75 Coupe deElegance
76 Coupe deVille
79 Coupe de ville with "Paris" (pick up) option and 472 motor
514 inch motor now in '73-

Offline Eric DeVirgilis CLC# 8621

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Re: 74 fleetwood AC
« Reply #10 on: June 15, 2017, 11:10:13 AM »
My experience is simply this: If you want your R12 system to perform as it should under extreme temperatures in stopped traffic, there is no getting around R12. That applies whether a '53 or an '83. UNLESS you make a TON of modifications that will enable the system perform as well on 134a.

Extensive article in  the Self Starter years back on just that - on a '66 DVC IIRC.  The writer who was obviously highly experienced with a/c claims to have worked perfectly after all was said and done but it was a complex project to say the least.

Do yourself a favor - keep it R12. 
A Cadillac Motorcar is a Possession for Which There is no Acceptable Substitute

Offline "Cadillac Kid" Greg Surfas 15364

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Re: 74 fleetwood AC
« Reply #11 on: June 15, 2017, 02:41:34 PM »
Eric,
That was me and it did work.  The cost, however was prohibitoive.
Greg Surfas
Cadillac Kid-Greg Surfas
CLC #15364
66 Coupe deVille (now gone to the UK)
72 Eldo Cpe  (now cruising the sands in Quatar)
73 Coupe deVille
75 Coupe deElegance
76 Coupe deVille
79 Coupe de ville with "Paris" (pick up) option and 472 motor
514 inch motor now in '73-

Offline Eric DeVirgilis CLC# 8621

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Re: 74 fleetwood AC
« Reply #12 on: June 15, 2017, 03:10:28 PM »
Eric,
That was me and it did work.  The cost, however was prohibitoive.
Greg Surfas

Well it was a great article and it do recall it being costly.

A '66 CdV or Conv was it?
A Cadillac Motorcar is a Possession for Which There is no Acceptable Substitute

Offline "Cadillac Kid" Greg Surfas 15364

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Re: 74 fleetwood AC
« Reply #13 on: June 15, 2017, 03:35:53 PM »
Actually I tried the modifications on both my '66 CDV and my 76 CDV with two modified VIR's.
Greg Surfas
Cadillac Kid-Greg Surfas
CLC #15364
66 Coupe deVille (now gone to the UK)
72 Eldo Cpe  (now cruising the sands in Quatar)
73 Coupe deVille
75 Coupe deElegance
76 Coupe deVille
79 Coupe de ville with "Paris" (pick up) option and 472 motor
514 inch motor now in '73-

Offline ithaca1230

  • 1974 Fleetwood
  • Posts: 42
  • Name: william epthimiatos
Re: 74 fleetwood AC
« Reply #14 on: June 15, 2017, 03:52:23 PM »
I got a couple buddies that said they might have a can or two kicking around. If they do I'll charge the system and see what happens.

Offline Eric DeVirgilis CLC# 8621

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Re: 74 fleetwood AC
« Reply #15 on: June 15, 2017, 04:06:11 PM »
It'll take a lot more than that. Have any R12 mineral oil on hand?
A Cadillac Motorcar is a Possession for Which There is no Acceptable Substitute

Offline Scot Minesinger

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Re: 74 fleetwood AC
« Reply #16 on: June 15, 2017, 04:33:21 PM »
Eric,

Hopefully when I see you in July at the interregional meet one of my friends with a 1974-76 Cadillac, such as Lynn Gardner will drive there with an r134 conversion, and then you can experience for yourself that really, it is fine, most complain that it can sub-cool their Cadillac in high.  For your 1962 Cadillac, agreed r12 is probably best.  really no one has ever complained about a 1971 or newer r134 Cadillac I converted not being cool enough.  However 1970 and older that I have converted some complaints arise, as it just does not have the capacity to make it 70'F inside when it is 90'F and sunny outside.

Weather permitting, see you in a month at Hershey!
Fairfax Station, VA  22039 (Washington DC Sub)
1970 Cadillac DeVille Convertible
1970 Cadillac Sedan DeVille
1970 four door Convertible w/Cadillac Warranty

Offline Eric DeVirgilis CLC# 8621

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Re: 74 fleetwood AC
« Reply #17 on: June 15, 2017, 04:47:53 PM »
Scot...sorry to say R12 wouldn't do any good in my '62 as it's a no a/c car. :(

I'll be delighted to see what that R134/R12 system can do - assuming it's hot enough that day to test the system's mettle. it would be the first converted system to "keep its cool" that I will have ever seen - and I've seen plenty - and all of 'em were lousy.

Most were okay under 85 deg at speed. Forget it when you stopped. You felt it immediately as you saw condensation forming on the outlets almost as quickly.

A Cadillac Motorcar is a Possession for Which There is no Acceptable Substitute

Offline STS05lg

  • Posts: 88
  • Name: Lynn W. Gardner
Re: 74 fleetwood AC
« Reply #18 on: June 15, 2017, 07:43:37 PM »
Eric,

I will be at the inter-regional meet in July at Hershey. Scot did both my 75 Sedan and 76 Talisman several years ago. The AC will make you feel like you are in a walk in cooler if you set it to Hi on the selector. You are welcome to try it out. I know on some systems, past corvettes, the r-134 did work as well as R-12 (but the ac systems in 70's-80's corvettes were not that great when new, I know because I owned several new ones in the 70's and 80's  and the AC did not cool on a Houston summer day when the cars were new}. However, the Cadillac system always was a step above and Scot's r-134 conversion has worked well for me in 40 year old cars.

Look forward to the the show at Hershey, see you there...

Best,

Lynn
1975 Sedan deVille
1976 Eldorado Convert.
1976 Fleetwood Talisman
2005 STS

1976 Sedan deVille (sold - PA)
1975 Sedan deVille (sold - WV)
1995 Seville (sold for parts)
1976 Seville (sold - VA)
1975 Coupe deVille (sold - AZ)
1976 Sedan deVille (sold - TX)
1976 Coupe deVille (sold - AL)
1973 Eldorado Convt. (sold - TX)
1976 Coupe deVille (sold - Sweden)
1976 Eldorado Convt. (sold - CA)

Offline Eric DeVirgilis CLC# 8621

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Re: 74 fleetwood AC
« Reply #19 on: June 16, 2017, 08:41:10 AM »
Looking forward to it.

Other issue with converted R12 systems is leakage meaning they are always needing to be recharged. Not the end of the world but somewhat inconvenient if you can't do it yourself. My 1977 has kept its charge in the 4 years I've owned it and never needed to be topped off.  That would never have happened on 134a.

Corvettes were always at an inherent disadvantage because the way the car is designed. System was never designed to take into account the added heat generated by the transmission casing which occupies a far greater portion of Corvette interior than in other cars.
A Cadillac Motorcar is a Possession for Which There is no Acceptable Substitute