Air Conditioning

[Shelly Harris]

Happiness is an A/C that works. My car came factory air. However the car now has a new compressor and runs on the new freon. Had the system vacuumed and recharged today and it's COLD... thankfully. We checked throughly for leaks and saw none, so I'm keeping my fingers crossed.

[Barry Wolk]

My car has air, but I never use it as I never put the top up.:D

[Shelly Harris]

You should exercise the A/c weekly - keeps the compressor lubricated, etc

[Shelly Harris]

Following up on my a/c. It's been a week and the system hasn't lost it's charge. HooRay !!!

Information which may be of interest. My a/c has a brand new (rebuilt, I think) compressor with freon 134a fittings, damper, and some switching. The original condenser coil is up front of the radiator and original evaporator coil in the rear. If you have factory air you will note in the rear trunk an a/c site glass which boldly states charge system to 6.5 lbs. pressure. My a/c service guy couldn't believe that number --- said it was higher than he had ever heard of or installed on anything. He remembered only going as high as 3.5 on some vehicles, so we took it to 3.5 Suffice to say it's blowing ice cold and I hope it stays that way.

[Barry Wolk]

I may be wrong but I believe you and your mechanic have interpreted the data incorrectly. That's not a pressure number it's the pounds of refrigerant necessary to fill the system.

My '77 Town Car specs call for 4.25 pounds of refrigerant. Using R134a you have to adjust that number downward by 15% to equal R12.

[Barry Wolk]

I checked the Technical Data Manual and it doesn't even mention air conditioning, only to the extent that the a/c cars had slightly larger tires.

Then I checked the Mark II encyclopedia and found that the a/c indeed is a 6.5 pound charge, not the pressure of the system.

I believe the large discrepancy between Lincolnaire and standard air conditioning is the sheer volume of the piping between the trunk and engine compartment. I believe the larger line is 1/2" in diameter. That would hold a lot of liquid freon.

[Nick DeSpirito]

Yes, the system takes 6.5lbs. of freon. There's copper lines that run to and from the compressor to the rear of the car into the evaporator with the dryer bolted to the front of the frame on the passenger side under the seat area opposite of the vacuum tank. There's a fan on either side of the evaporator case which blows the cold air through ducts that run through the blind quarters and up to the roof and out the 4 outlets. These outlets can be adjusted for volume and direction. There is also a vacuum switch on the throtte linkage just behind the air cleaner which is activated when the air conditioning lever is pulled forward to increase the idle level by means of a fork at the end, thus pulling the linkage up and increasing RPM. The fresh air intakes can be shut off by turning the knob on the package tray. Air is then recirculated from the cabin via a grate that runs the full length of the package tray just above the rear seat. This was for 1956. For 1957, the Quarter fresh air intakes were eliminated and fresh air was brought in via ducting that ran from the evaporator to the engine compartment and tied into the blower motor housings on either side of the front fenders. There's also a sight glass on the compressor for oil. If my memory is correct, it takes 10 oz. of compressor oil.

[Mad Scientist]

Without out double checking I believe the the label in the truck says a "maximum" of 6.5lb.

But if you ever take a look the evaporator in back it is massive. It probably has as much surface area the evaporator my home. The condenser in front is also generously proportioned. Plus all the 1/2 and 3/8" tubing running back and forth. So 6.5lb is probably not that unrealistic.

[Nick DeSpirito]

Mad,

You got that right. It is big. The expansion valve is also back there to the right of the evaporator. With the length of the lines and the size of the evaporator, it's no wonder that it takes 6.5lbs. to charge. Like Barry said for his '77 and I know for my '76 Mark IV, they take 4.25lbs. So, 6.5lbs. is not unreasonable for the Mark II.

Here's a picture of the sight glass decal that's in the trunk.

http://www.parts123.com/parts123/yb.dll?parta~showpic~Z5Z5Z50000129a~Z5Z5Z5AAAPS~Z5 Z5Z5~Z5Z5Z5~Z5Z5Z5

BTW, if anyone needs a decal set for the Mark II, they are available from the Mid-Atlantic Region of the LCOC.

[Nick DeSpirito]

Two things I forgot to address. Say the fresh air ducts on a '56 are open and it's raining. Where does the water go? The ducts (hoses) that comes off the air intakes loop down over the top of the wheel wells before going up into the blower motor housings and the water actually drains out from the top of the wheel wells.

Where does the condensation water drain from the evaporator? The whole evaporator sits in a pan and in the bottom of that pan is a hole with a rubber tube that sticks out of the bottom of the car. This tube is round at the top where it connects to the drain hole, but is flat at the other end so the water can drain out, but nothing can get inside.

[Barry Wolk]

I've heard that those intake tubes leak in heavy rain and water enters the trunk, rotting out the fenders. I would think it would be a simple fix to line the bottom of the hose with plastic, providing a waterproof path to the pan drain.

The slab-side has a cowl drain on the firewall that's shaped as you describe the Lincolnaire drain, except that none seem to have survived. That hole is big enough to let mice in the cowl area, and if the vents are open, right into the car.

[Nick DeSpirito]

The intake drains are sort of a "T" connection that are mounted on tops of the wheel wells. The hose comes down from the intake and connects to the front side of the T. Water drains there. Another hose connects to the back side of the T and loops down and back up to the blower motor housing. The drain hoses are hidden from view under those carpet donuts on either side of the trunk.

I can see water getting into the trunk if the hose ruptures or disintegrates from age. If the car is out in the rain a lot, (mine is allergic to water :D) they should be routinely checked.

I don't remember because it's been a couple of decades, but I think I purchased a repro of the evaporator pan drain hose for my car which I don't think is available now.

[Shelly Harris]

Where does the condensation water drain from the evaporator? The whole evaporator sits in a pan and in the bottom of that pan is a hole with a rubber tube that sticks out of the bottom of the car. This tube is round at the top where it connects to the drain hole, but is flat at the other end so the water can drain out, but nothing can get inside.

Actually there are three of those which I saw when the car was on the rack. Also copper lines to the rear are not being used. Two 1/2" rubber A/C hoses run fron the compressor back to the evaporator.

But, I'm confused. My mechanic says he charged the system to 3.5 Since freon 134a is 15% less than 6.5= 5.5 are you saying two more lbs should be added?

[Nick DeSpirito]

Shelly,

Did your mechanic check the sight glass in the trunk? If the system is full, you will not see any bubbles in the tube. There's also a metal filter in the evaporator case that should be occasionally cleaned. I charged my system around 8 or 9 years ago when I had the engine out to rebuild the transmission and haven't touched it since. It's still holding the charge, thank God.

Take an air temp reading at a register and see what you get. Should be 38-40 degrees. Did you have the original the compressor rebuilt? I don't think they are available new, unless you found a NOS. Here's a picture of the original compressor and clutch assembly.

http://www.parts123.com/parts123/yb.dll?parta~showpic~Z5Z5Z50000129a~Z5Z5Z5AADCW~Z5 Z5Z5~Z5Z5Z5~Z5Z5Z5

[Barry Wolk]

Not two pounds more, just the difference between 6.5 pounds less 15%, and the 3.5 pounds already installed.

Actually, since your system has been modified with adding rubber hoses of unknown diameter I would use Nick's method of simply checking the sight glass for bubbles as you fill the system.

You're getting some cooling, just not the maximum amount. The system should literally send a chill down your spine.:D

[SLK]

My system is currenty empty. I'm thinking this is the best time to rebuild the system with new seals and change over to 134a. Your thoughts?

[Barry Wolk]

Our in-house Mad Scientist will know, for sure.

[Shelly Harris]

My system is currenty empty. I'm thinking this is the best time to rebuild the system with new seals and change over to 134a. Your thoughts?


Why? What's not working? If your compressor and other items are ok then I'd recharge with F 12 along with the appropriate amount of oil and sealant.

[SLK]

Why? What's not working? If your compressor and other items are ok then I'd recharge with F 12 along with the appropriate amount of oil and sealant.

It doesn't blow cold air. I figured with the cost of R12, now would be the time to switch. I don't want to refill the R12 and then find it has a leak.

[Barry Wolk]

Leaks can be fixed. R-134a is not all it's cracked up to be, nor is it proving to be environmentally friendly.

[Mad Scientist]

My system is currenty empty. I'm thinking this is the best time to rebuild the system with new seals and change over to 134a. Your thoughts?

Well if you system is empty this is probably a good time to go for new seals.
It is my understanding that if the system had a small almost insignificant leak with R12 to the new refrigerants that leak would look like a screen door.

[depmike38]

I don't know guys. If mine doesn't function properly I'll probably change it to the R-134. I know the R-12 is still available though a bit pricey and I've got access to enough to do it. The main problem is that unless you have equipment to pull the system down of your own almost none of the a/c mechanics(in my area anyway) have it anymore and they can't hook up to the old style fittings with the new R-134 hoses anyway. I've changed a number of my older cars over by getting a fitting adapter kit from an auto parts house, pulling a vacuum on it and recharging it with the newer refrigerant. Nice and cold and if you get a leak it's only about $5.50 a lb. I have heard though about the R-12 hoses being somewhat porous to R-134 I've just never had any real problem. I would change the o-rings though.:)

[Keith W Colonna]

I replaced my compressor with an original and had the hoses rebuilt.
I then charged with R-12. No leaks were found at first using the appropriate tests. Next day, all refrigerants was gone. and the leak was obvious around the sight glass with dripping oil as well. The compressore was sent for repair (twice), each time lost the R-12 while problems were diagnosed. In the end I charged with 134 having lost several hundreds of $'s in R12. The 134 cools fine now.

[Chuck Lutz]

I'm assuming that by the discussion, the R12 is still available? Sorry, I'm in CA. If the neighors should find out that we have a can, there'd be line of yellow tape around four blocks and a hazmat team with me spread eagle on the front lawn. I wouldn't be respected at Starbucks in the morning. (for the record, I'm a Pittsburgher originally)

[depmike38]

They don't make it anymore but a cooperative parts guy can still get it for you if you have an a/c certification or know someone that does. It's funny but if I recollect correctly Dupont held the rights to R12 for years until it got to where anyone could provide it and it was .99 a can. Then it suddenly R12 was bad for you and R134 was good and guess who has/had the rights to it. You can however put together a cheap driveway method to put it in if you want the R12. Works pretty well on a vehicle with a sight glass. If anyone needs it I can give you the list of what to get. Probably about $50 for all.:D

[Don Henschel]

:oYes it holds 6.5 lbs. Look under your car and take a look at that mutant sized drier under the floor (passenger side). I just looked at mine and its almost a foot long. This drier has a desiccant to absorb moisture from the system. It also acts as a resevoir for the refrigerant. As for the sight glass, if it is clear for 134A you are overcharged. When I started with 134A conversions in the early 90's, most of us didnt know about the 15+% less and assumed you charged until the sight glass was clear, and in some systems an additional pound was required after the sight glass cleared (R12). Not with 134A, and it's quite normal to see bubbles or a milky sight glass. If it was a piece of farm equipment of which the quantity of refrigerant was not known, I would operate the engine at operating RPM with a thermometer in the evaporator discharge vent. Once the temperature stopped dropping I stopped charging as I had reached the maximum efficiency of that system. If I charged it with more, you would see the temperature start to rise! For 134A, the R12 mineral oil (in the compressor)should be drained and refilled with Polyolester, a Synthetic oil. I was told and have found flushing of the system was not required to remove all the mineral oil unless the compressor burned out and contaminated the system. Polyolester will easily disolve most of the residual oil left behind, unlike the PAG oils which need a very clean system. If I had R12 I would still use it. I have a very good electronic leak detector, and I just wouldnt put it in until all leaks were repaired. New hoses probably would be a good idea if you are rebuilding your system, along with getting your drier reconditioned. Classic auto air has most of the parts for your Mark II including parts to restore the compressor, as well as rebuilt HH Techumseh compressors and clutches.

[Don Henschel]

They don't make it anymore but a cooperative parts guy can still get it for you if you have an a/c certification or know someone that does. It's funny but if I recollect correctly Dupont held the rights to R12 for years until it got to where anyone could provide it and it was .99 a can. Then it suddenly R12 was bad for you and R134 was good and guess who has/had the rights to it. You can however put together a cheap driveway method to put it in if you want the R12. Works pretty well on a vehicle with a sight glass. If anyone needs it I can give you the list of what to get. Probably about $50 for all.:D

I was told a couple of weeks ago its easy to get in the States. I spied a 1 lb can on the desk of a service manager in a repair shop nearby. I smiled and asked where he managed to get his hands on the contraband. His comment was he got it from across the border from an automotive parts store. He claimed it was very easy to get down in the states, just a bit tricky to get accross the border. If you do the cheap driveway method, please don't hook the can up to the high or discharge side of the compressor as your can will turn into a bomb from having the freon pumped back in! Also check your oil level in your compressor(if you have the sight glass front left side of compressor) or you will burn it out after you recharge the system. Dont invert the can and send liquid into your compressor when its running or you will damage your valves in the compressor!

[depmike38]

Don, one of the things I was referring to is a method of pulling a vacuum on the system before replacing the freon. The a/c shops always had a fairly expensive set-up that most hobbiest just didn't have reason to buy for infrequent use that was electric. Harbor Freight tools sells an air operated a/c vacuum pump for $10. Then use go to the auto parts store and buy about $7 worth of fittings to adapt it to whatever freon you use. Then as you said make sure to use the low side fitting and vacuum out the system. I've used one of these things at the shop repeatedly and it's surprisingly durable. Makes getting that first can or two in much easier.

[Don Henschel]

Well if you system is empty this is probably a good time to go for new seals.
It is my understanding that if the system had a small almost insignificant leak with R12 to the new refrigerants that leak would look like a screen door.

It's actually not all that bad. I found alot of times if the hoses are in reasonable condition, the 134 wont leak out and last a very reasonable lenght of time. The parts for this car are becoming scarce as can be and as far as I know (correct me if I'm wrong) the last year for the HH Techumseh, was 57, and then the York and newer smaller versions of the Techumseh came out, give or take a year or two. Only used parts seem to be available other than repro gaskets, bearings and clutch brushes. Everything else is good used parts such as crankshafts, crankshaft bellows seal/carbon ring, etc. From what Curtis at Classic Auto Air Mfg. was telling me a month ago, the worst part for being scarce is the clutch hub assembly (the plate with the springs that pulls against the coil housing).The springs break if you ingage the clutch at engine speeds greater than idle speed. Also this clutch plate has a thin coating of asbestos which wears off as well resulting in a slipping clutch due to the very small contact area unlike the newer clutches running metal to metal. This hub alone is worth $250.00 by itself. If you have a working or very little required to get working system, do yourself a very big favour and spend a bit more money and replace 50+ year old seals, tired hoses, and of course dump the compressor oil and refill with proper amount of refrigerant oil. Get the receiver drier rebuilt (water in the system combines with the freon to produce acid as well as ice). If you are not sure what you will be putting in for refrigerant (R12 or 134A) you can fill your compressor with Polyolester since it is compatible with R12 and 134A (so I have been told and read) http://www.cszindustrial.com/documents/articles/retrofitguidelines.htm
http://en.wikipedia.org/wiki/Polyolester

[jackfish]

Hello,

Forgive me for my lack of technical knowledge/limited technical vocabulary. I'm looking for (what I believe to be) the main A/C hose. I have attached two photos of the connections.

Does anyone have a drawing/specs/photo of the missing hose?
917
918

Even better, does anyone have an extra hose (either original in great condition or modern fabrication) laying around that they'd like to sell?

Thank you,

Greg Pallister
403-782-6745

[Barry Wolk]

Any decent hydraulics house should be able to fabricate a modern replacement. Take your old one with you. The only way you're going to get the authentic braiding is to find a used replacement.

You might want to clean up the threads and the beveled mating surface before you put it back together.

[jackfish]

Thanks for the advice. I don't have the old hose to use as a reference. Unfortunately, it disappeared during the restoration process. That's why I'm hoping someone has a unused spare laying around collecting dust.

Thanks,

Greg

[linmk2]

Some years ago I had new hoses made by Classic Auto Air in Florida. http://www.classicautoair.com/

It was a long time ago, but they seemed to know what they were doing. You might contact them. Hope this helps.

[Barry Wolk]

I took a look at mine. It would take a pretty skilled fabricator to duplicate those fittings. Look through the vendors list. You might get lucky.

[jackfish]

Thank you. I contacted the fellows in Florida and they are looking into the project.

Greg

[markiient]

Thank you. I contacted the fellows in Florida and they are looking into the project.

Greg

I have the exact tooling to reproduce the AC hose brass fittings with all the correct lettering, etc. We had these machined from a solid piece of brass. I haven't been able to locate the correct black braided covered hose suitable for AC. If there is a interest in the fittings I'll do some research.

[Barry Wolk]

I wonder how it would look to simply sheath a piece of externally braided hose with a heat shrink tubing. In my trade I've seen all different shades and gloss to these products. That would replicate the look of the original hose as the braid would leave an embossed look on the surface, just like the original.

Actually, you could just slide a braid section over the standard refrigerant hose and heat shrink over that.

Just my $.02.

[markiient]

I wonder how it would look to simply sheath a piece of externally braided hose with a heat shrink tubing. In my trade I've seen all different shades and gloss to these products. That would replicate the look of the original hose as the braid would leave an embossed look on the surface, just like the original.

Actually, you could just slide a braid section over the standard refrigerant hose and heat shrink over that.

Just my $.02.

A few years ago I located the correct braided hose in red that was compatiable with freon. I thought of coloring it black. As mentioned above, if we could locate a correct braided sheath and heat shrink them is another idea. The cost to machine the fittings was quite costly. We made 25-pieces and sold most of them quickly. The machinist said he lost money making the fittings so we never made any more. I'll get a quote from my machinist and see if it's cost effective to make them.

[Pat Marshall]

The original Mark II braided hoses have 2 braided components. 1) the outer covering and 2) the inner braided metal hose itself. Both have the braided pattern. So if your outer layer is deteriorated why not just carefully remove it and then paint the inner braided metal line black to match the missing outer layer? Possibly a rubberized battery tray paint might do the trick?

[Pat Marshall]

I have the exact tooling to reproduce the AC hose brass fittings with all the correct lettering, etc. We had these machined from a solid piece of brass. I haven't been able to locate the correct black braided covered hose suitable for AC. If there is a interest in the fittings I'll do some research.

Jack, here is a link to the Dunham Website. they carry Aeroquip Black Braided A/C hose that will handle Refrigerant 134a. See catalog image below.

Also, this is an update I found their hose for Refrigerant 12. See catalog image below.

http://dunham.thomasnet.com/viewitems/lic-hose-aeroquip-single-wire-braid-hydraulic-hose/aeroquip-fc558-refrigeration-air-conditioning?&bc=100|1518|1239|1508

[Don Henschel]

Any decent hydraulics house should be able to fabricate a modern replacement. Take your old one with you. The only way you're going to get the authentic braiding is to find a used replacement.

You might want to clean up the threads and the beveled mating surface before you put it back together.

Its not even close to hydraulic hose. It's a high pressure hose (the modern A/C hose) able to handle around 500 psi. Your typical R-12 hose had a rubber sleeve in the middle with a cotton or nylon braid over it covered with a protective outer rubber jacket. The problem with using the older R-12 hose for 134 is it tended to allow the 134 to leak out. The theory was the 134 molecules were smaller. When I used to do 134 conversions I didn't have too many problems with this unless the hoses were quite tired. The 134 hose has a plastic inner liner to prevent this. Refrigerant hose is soft enough to be clamped with a worm gear hose clamp (I used to use crimped ferules instead) whereas hydraulic hose is too ridged. If you are in a hurry since your car is going to auction, just look up in the yellow pages automotive air conditioning and most places have bulk hoses and fittings and can just make one up close enough to work.

[Pat Marshall]

I have the exact tooling to reproduce the AC hose brass fittings with all the correct lettering, etc. We had these machined from a solid piece of brass. I haven't been able to locate the correct black braided covered hose suitable for AC. If there is a interest in the fittings I'll do some research.

Jack I previously mentioned that I have found braided A/C hoses for Refrigerant 12 and 134a. I have ordered a sample. would you like for me to send a piece of it? It is .500 ID an .92 OD.

I have interest in your resurrecting this poject. I encourage other Forum members to express interest (if they have any). This was a good offer from Jack, so we should give him some feedback.

Jack which fittings did you make tooling for?

[Rick Payton]

I would be interested

[markiient]

Jack I previously mentioned that I have found braided A/C hoses for Refrigerant 12 and 134a. I have ordered a sample. would you like for me to send a piece of it? It is .500 ID an .92 OD.

I have interest in your resurrecting this poject. I encourage other Forum members to express interest (if they have any). This was a good offer from Jack, so we should give him some feedback.

Jack which fittings did you make tooling for?

I have the tooling for the large hose. Send me a sample and I will see if is the correct size to match my tooling.