[ccweems]

When I look at all the expense and work to restore the a/c in my 560SL to new condition and then remember that it didn't work that well in Houston to begin with I started thinking...

What about keeping all of the a/c and defroster vents and pitching all of the rest? Vintage Air has been very successful in designing a/c for hot rods and older US models for over 30 years. They have a small evaporator/plenum that looks like it may fit. It uses servos like recent factory a/c uses. I would replace the compressor and condenser to match the new evaporator to create a far more powerful system than it was born with. It has 4 Mercedes looking knobs that could be put on a new panel which would look authentic to anyone but MB enthusiasts. The parts for everything (excluding MB console wood) are about $1000.

Think about it and tell me I'm not crazy. Get rid of all the vacuum hoses. Have a high performance system designed for R-134A. Install parts made in this century which will be a fraction of the price of OEM parts. Controls whose functions are readily understood.

Sure there will be those who are purists who will disagree but I expect that a well engineered (I'm a mechanical engineer) and attractive system that works will add value. Any car with working original a/c is still a ticking bomb. Common 107 a/c repairs costs as much as this new system costs complete.

What say you?


http://www.vintageair.com/catalog10/2010 VintageAir Catalog web hi-res (Page 16).pdf

 

[nobby]

When I look at all the expense and work to restore the a/c in my 560SL to new condition and then remember that it didn't work that well in Houston to begin with I started thinking...

What about keeping all of the a/c and defroster vents and pitching all of the rest? Vintage Air has been very successful in designing a/c for hot rods and older US models for over 30 years. They have a small evaporator/plenum that looks like it may fit. It uses servos like recent factory a/c uses. I would replace the compressor and condenser to match the new evaporator to create a far more powerful system than it was born with. It has 4 Mercedes looking knobs that could be put on a new panel which would look authentic to anyone but MB enthusiasts. The parts for everything (excluding MB console wood) are about $1000.

Think about it and tell me I'm not crazy. Get rid of all the vacuum hoses. Have a high performance system designed for R-134A. Install parts made in this century which will be a fraction of the price of OEM parts. Controls whose functions are readily understood.

Sure there will be those who are purists who will disagree but I expect that a well engineered (I'm a mechanical engineer) and attractive system that works will add value. Any car with working original a/c is still a ticking bomb. Common 107 a/c repairs costs as much as this new system costs complete.

What say you?


http://www.vintageair.com/catalog10/2010 VintageAir Catalog web hi-res (Page 16).pdf

I say.........if you need air and you love to drive YOUR car (it is your car, after all) and there is something that will fit and work better....then why not?

How many of us have upgraded our sound systems?

AND...............it would be a great "How To" thread.


I say go for it.

 

[GlueckAuf]

For the pre-ACC III generation systems with those outsourced compressors, baffling controls, and general "what-the-hell-were-they-thinking" technical messiness, I would heartily agree. My impression is that Mercedes invested very little engineering thought into those early AC systems because they were for the most part only demanded by the US market. AC on German-market cars in this era was very rare. (For that matter, AC in German houses was almost unheard of.)

There's a lot of junk stuffed under the SL's dash, and precious little room to stuff more. There's no getting around that system integration would be the most challenging aspect, and there would be no shortage of compromises required in ducting, appearance, and operation...but on a 110F-in-the-shade Texas afternoon when the asphalt is bubbling and panting dogs don't even want to move, I imagine your priorities change.

My 560 SL's post-ACC III system is very well-engineered, intuitive, and reliable (knock, knock, knock), so I wouldn't even consider tearing it out and transplanting an after-market system...yet. Good luck, and if you take the plunge, post your progress.

Good road,

 

[dugald]

My 560 SL's post-ACC III system is very well-engineered, intuitive, and reliable (knock, knock, knock),

Not to start a bunfight with the esteemed GA, but if that's so, how come mine and many others don't work?
Seems to me it's a weak point for all 107s.

 

[sundaygolfer]

I am with you brother...my car will be moved to Florida with the intention of someone down there hooking up a Vintage air mini. Hot rodders here do not like the local installer.
There was an article somewhere that critique the Mercedes system...the early compressor was too large and the condenser was too small. The remainder needed to be replaced by new technology.
The only scary thing is the monster of wires and hoses under the dash. They are real because there are pictures of it on this and other forums. I have a 1973 which may only be a mini monster

 

[Djenka018]

I do not agree that AC in the car/house was demanded by US market only.

If you had a full brick built house you'd understand why AC in the fully brick/concrete built german house was commonly rare. Same rareness like maybe the heating in southern Texan houses.

@ ccweems
Yes, if you have an auto AC for US market that is failing beyond economical repair, by all means have it dumped and throw in something cheaper (by the $ amount). Anything engineered 30yrs later is more reliable anyway.
Not everyone is purist and not every car is meant to stay original. We all have 107's or Mercs for totally different reasons. If you do not intend to brag how much you car is identical to factory condition, why bother keeping it such. When you decide to sell it, some will like it, some will not. If I was a purist buyer and that was the one of a few non pure features on the car, it would not bother me as it is reversible. You could keep the original parts and throw them in with your car (for purists to revert it) when you decide to sell it.

I have keyless entry, an alarm, immobiliser, close to but not quite period correct radio and additional electric vacuum pump (to aid unlocking all the locks after engine vacuum is long gone) and yet I consider my car to be fairly pure. It's just features I consider essential for normal usage of the non-garage queen car. Your AC proposal would not be extreme for your list of essential features.

 

[nobby]

I do not agree that AC in the car/house was demanded by US market only.

If you had a full brick built house you'd understand why AC in the fully brick/concrete built german house was commonly rare. Same rareness like maybe the heating in southern Texan houses.

@ ccweems
Yes, if you have an auto AC for US market that is failing beyond economical repair, by all means have it dumped and throw in something cheaper (by the $ amount). Anything engineered 30yrs later is more reliable anyway.
Not everyone is purist and not every car is meant to stay original. We all have 107's or Mercs for totally different reasons. If you do not intend to brag how much you car is identical to factory condition, why bother keeping it such. When you decide to sell it, some will like it, some will not. If I was a purist buyer and that was the one of a few non pure features on the car, it would not bother me as it is reversible. You could keep the original parts and throw them in with your car (for purists to revert it) when you decide to sell it.

I have keyless entry, an alarm, immobiliser, close to but not quite period correct radio and additional electric vacuum pump (to aid unlocking all the locks after engine vacuum is long gone) and yet I consider my car to be fairly pure. It's just features I consider essential for normal usage of the non-garage queen car. Your AC proposal would not be extreme for your list of essential features.

I was going to say that.

 

[roncallo]

I worked on these cars when they were new. I always found the AC systems on MB's of those days to be extremely inadequate and far behind the American cars of the day.

Basically they sucked back then with R-12 and with R134 they suck even more. The reliability of them is not too bad with the exception of the push button unit. The push button units are about the only thing that fails regularly. Of course after 22 years you will need all new vacuum diaphragms. Once those are replace your good for another 10 to 20 years.

Biggest problem is that the vacuum diaphragms are hard to replace. However they are not as hard to replace as I would suspect a nicely engineered installation of that system will be.

 

[GlueckAuf]

Not to start a bunfight with the esteemed GA, but if that's so, how come mine and many others don't work?
Seems to me it's a weak point for all 107s.

Here are my top 5 suggestions why you and others with similar ACC problems might rightly differ with my high opinion of the post-ACC-III air conditioning system in the 1986-1989 560 SL:


5. They're hard to diagnose because the special tools depicted in the service literature probably disappeared long ago. (I had to build my own to do even basic troubleshooting.)

4. They depend on a sound heater, vacuum lines, blower motor and its regulator, and the electrics that serve them.

3. They're at least 21 years old with, in many cases, questionable service and maintenance records. Air conditioning systems hate air, dirt, water, and overcharging. DIY procedures often introduce these, and service life suffers.

2. The parts to repair them are prohibitively expensive for many, so they do without. (It's a roadster, after all.)

And at the top of the list...

1. They require a refrigerant (R-12) that is banned in your country altogether I believe, and difficult to legally procure and use in mine. Most shops won't handle R-12, insisting to do a conversion instead, and many don't do everything a proper conversion requires for long, trouble-free service. R-134a introduces a set of requirements and properties that wear out their overloaded compressors faster, can react with the old mineral oil to form acids that destroy them (called the Black Death), and without upgraded hoses will leak out prematurely. Even if done properly, a converted system will never deliver the cooling the original R-12 provided. R-12-like substitutes introduce a different set of system compromises.

But I contend the basic engineering design is sound, durable, and easy to operate. The earlier R107 Automatic Climate Control systems (ACC I and II) I was comparing mine to was not, in my opinion. (But, admittedly, this is based entirely upon observation and the opinions of others here that have struggled with them, not personal experience. Somebody out there might actually love their late-70s SL's Chrysler-designed air conditioner. )

Good road,

 

[GlueckAuf]

I do not agree that AC in the car/house was demanded by US market only.

If you had a full brick built house you'd understand why AC in the fully brick/concrete built german house was commonly rare. Same rareness like maybe the heating in southern Texan houses.

I did, and I do, bud. For nearly 20 years. And I agree, in Bavaria, we rarely needed AC in our brick and stucco home. Screened windows would've been nice though. (With all the dairy cattle and honey'd fields in the summertime, the flies could drive you to distraction.)

When I lived there in 1980-83, you almost never came across a German car with AC, hence my point about their putting them almost exclusively into cars destined for Mercedes's biggest export market, the US. And those early, outsourced AC systems were pretty crude by any standard, let alone the Mercedes standard.

When I returned in 1991 and remained through 2005, air conditioning (Klimaanlage) had already become standard in the high end and was steadily trickling down to the lower end of the German domestic car spectrum. With German drivers now a primary customer for automotive air conditioning, Mercedes raised its engineering standards considerably from the crude, almost afterthought level it was when only the export models demanded them.

Good road,

 

[roncallo]

I did, and I do, bud. For nearly 20 years. And I agree, in Bavaria, we rarely needed AC in our brick and stucco home. Screened windows would've been nice though. (With all the dairy cattle and honey'd fields in the summertime, the flies could drive you to distraction.)

When I lived there in 1980-83, you almost never came across a German car with AC, hence my point about their putting them almost exclusively into cars destined for Mercedes's biggest export market, the US. And those early, outsourced AC systems were pretty crude by any standard, let alone the Mercedes standard.

When I returned in 1991 and remained through 2005, air conditioning (Klimaanlage) had already become standard in the high end and was steadily trickling down to the lower end of the German domestic car spectrum. With German drivers now a primary customer for automotive air conditioning, Mercedes raised its engineering standards considerably from the crude, almost afterthought level it was when only the export models demanded them.

Good road,

Yes the turning point came around 1990 with the introduction of the 129 and in 1992 with the 140. Same with the stereo systems.

 

[ccweems]

Point well taken dugald. I'm sure that there are those with Becker cassette decks in perfect working order complete with the original speakers that see no reason to go to CD's either.

I look at all of the MB components including compressor, condenser evaporator, vents and controls and don't see one component that was a class leader at the time of manufacture nor competitive today. My a/c works now (don't ask about the heater) and can't bear the thought of spending hundreds of dollars to replace components that have been obsolete for years.

Cut GA some slack. How much a/c do you need for the week of hot weather in MI? I understand the the historically poor MB a/c performance was due to the testing location: New Jersey. The story goes that they would ship over a few samples to NJ (MB's headquarters at the time) and they would drive them around in 85F weather and announce them fit for production. When cars would hit Houston they would find out that the a/c wasn't strong enough and that the additional load caused the car to over heat.

Now cars from many manufacturers land at the Houston port and are driven on I-10 to San Diego and back for a/c testing. During the summer caravans of cars with manufacturer's plates are a common sight on I-10 including models that are never imported into the US. Nobody complains about a/c performance anymore.

 

[GlueckAuf]

Cut GA some slack. How much a/c do you need for the week of hot weather in MI?

Not to belabor the point, but my permanent home is in McKinney. Last July I drove my '87 560 SL from Detroit to Dallas and back for the Fourth. No issues, and that includes AC issues. I had the hardtop on, and I'm sure that aids the efficiency, but I can honestly tell you my factory AC (with genuine R-12) kept the cabin comfortable, both on the Interstate and in town.

So, if you're soliciting truthful opinions about your proposed modification, that's mine. Worth every penny you paid for it.

Good road,

 

[gerkebi]

My a/c works fine, but I still like the idea.

 

[ccweems]

Ok, in the absence of any technical arguments not to do it I'll go forward. I've got to finish the interior refresh first (console, rebuild seats, dye leather and new carpets). Vintage Air is just down the road and they seem ready to give some assistance if needed. I'll promise to take pictures, list components and provide drawings if required. The only issue I see is so far adding a relay so that a/c will always be in recirculate mode and heat or vent will always use fresh air and finding some back lit labels that look like they are OEM sourced.

 

[Ears]

...The only issue I see is so far adding a relay so that a/c will always be in recirculate mode...

Why do you want this? Should not be a problem, but I think an extremely hot car would benefit from exterior air coming in to be cooled, then switch over to recirculate after temp inside has moderated somewhat...

 

[Djenka018]

Couldn't you just use original manal AC console board and integrate new controls into it?

 

[mbslns]

OK, I already have the VA mini unit and the dash out and AC removed. The project is temporarily stalled, but as I get back to it in the next few weeks, I'd be happy to take photos and solicit advice.
As long as I get to keep sniping and half-assed contributing as I always have.

 

[rowdie]

As long as I get to keep sniping and half-assed contributing as I always have.

Why should you be any different than most of us?

 

[RadioTek]

Please make a record of your process to put in the E.G., My A/C system is nonfunctional, and badly neglected. When SWMBO gets back to work and I can free up some funds, this sounds like the way to go. I had contemplated something like this a while ago, but doubted Vintage Air would have a kit usable in something as exotic as a 107. Nice to find out they do have one.

Best of fortune with the job,
Scott