Air Condition

[Jack Bowser]

Today I took my Mark II to my local radiator shop to have my system charged in hopes that it may still be in working order.

Who knows how long my system has been without the R-12 but everything was there and looking to be in good condition.

I know it hasn't been working since I bought 2198 last fall and I was told by a previous owner that it sat in a Museum for quite some time.

On the plate by the window in the front of the trunk, it says to charge the system to a max of 6 Pounds.

We put in 2 pounds to start and watched for the dye to see if there are any leaks in the system,

The system blew 60 degree temp air at idle.

Everything seem to be working OK so we put another 2 pounds of R-12 in and the temp came down some more.

I drove home a happy camper with working air conditioning. Time will tell if there is a small leak somewhere.

I just had to tell someone. Ha

[Jeff Smith]

I have to ask: where did you go that still had R 12 available? I thought those days had long passed. Hope it continues to work with no leaks. Congratulations

[jdsnoddy]

How much did you pay for two pounds of R-12?
I'm happy for you that all is well.
John

[Jack Bowser]

Hi Jeff, We have a great Radiator shop here in my area and he still has some R 12. It's $80.00 a pound so I hope it doesn't leak.

It's been 9 days since he charged it and it's still blowing nice and cold so I may be lucky.

[Jack Bowser]

Hi John, $80.00 a pound and we put in 4 pounds.

The tag on the system in the trunk says 6.5 pounds max but my system is blowing nice and cold with 4 pounds.

[jdsnoddy]

That is great deal. Thanks so much. John

[JAPAC]

All I can say is good for you. It seems I've always had ac problems and trouble finding someone to solve them.

[Keith W Colonna]

I once lost a full charge of R12 when reactivating my system with a rebuilt compressor. There was an unidentified leak in a line under the car.
Since then, I've switched to 134 (not to start that debate again). An old timer told me that he used to subscribe to the evacuate, purge, change oil process, but in the many years since then he has topped off old R12 systems, adding new oil if needed, charging to lower pressures and had great results. I've used that procedure without problems for years....that's my experience. I'd use R12 again except for that terrible $$$$ loss when it leaked out.

[Don Henschel]

Generally I pressure test any system after recovering what's left of R12/134 before evacuating (place the system on a vacuum) and recharging. I have had systems that leaked out slowly due to cracks on compressor housings due to bolts that were too long and bottomed out in the hole or leaking crimps on hoses or hoses in general. It also has to hold vacuum as well and I have seen where a damaged hose held under pressure but leaked under vacuum! And how many compressors have we seen burned out because whoever "charged" the system lacked the knowledge or ambition to check the oil level often lost during a leak?? If they don't make any attempt to check and or add oil walk away! At least there are places down in the States still selling R12 not up here in Canada. I also stay away from those butane/propane refrigerants as well. I replaced enough compressors wrecked from that garbage due to only 30% being required which isn't enough refrigerant to properly carry and circulate the oil around unless more oil is added. Quite simply Mickey Mouse!

[Matt Cashion]

I agree with Don. A standing pressure test with nitrogen should be done anytime the system is opened up or major component replaced. Soap bubble test all fittings that were loosened during repairs as well. I like Big Blue leak detector myself as it produces micro bubbles on very small leaks.

[Don Henschel]

Actually I have a deadly sensitive leak detector that cost quite a bit but soap is also good. Problem is I have found some miserable leaks the hard way on the newer aluminum York and cast iron Tecumseh compressors. The worst was a York that was brand new remanufactured and this system had a mysterious leak that only happened when running. It was a hairline crack in the mounting bolt area and the only way I found it was a very high pressure test. On agriculture or off road heavy duty equipment systems you will typically find text book operating pressures but automotive with thermostatic viscous fans that don't cut in until things are roasting hot can give pressures sky high on the automotive systems, enough to make ones hair stand up!! After seeing sky high pressures in some automotive systems prompted me to really raise test pressures and this was the only way the leak showed up on the York! Under cooler temps and lower pressure things were fine. On hot days and with chaff and dust on the condenser raising the pressure, this is when the system would leak, when it was most needed. Over 300 PSI was needed to expose the leak and normally the off road/Ag equipment has much better cooling capabilities than automotive and pressures this high are seldom seen unless safety switches are bypassed and the condenser is plugged. As for the 6.5 pounds, typically on the R12 systems the rule of thumb was charge until the sight glass clears and add another 1/2-1 pound more. Keep in mind that is liquid in the sight glass at this point and the extra half to one pound is stored in the Reciever Drier and the drier on our Mark II's are quite simply MASSIVE. The amount can be reduced if a much smaller universal/aftermarket drier/accumulator is subbed for the original. As it has been mentioned in the past with R134 the amount used is only 70-80 % of the original amount of R12. I remember when it first came out in the early 90's and all of the extreme horror stories of what was required to convert including replacing the R12 components with larger such as the condenser in front of the radiator or the evaporator in the cab. In reality being a new product we assumed you charged until the site glass was clear. Totally wrong and in reality by the time the glass was clear you were grossly overcharged! It eventually came to the point of charging to maximum efficiency and no more and I had to literally use a digital thermometer in the discharge with the engine at high idle roaring away and very slowly charging watching the temperature drop. When it quit dropping I shut the gas off and if one was distracted or day dreaming you would actually see the temperature start to rise indicating overcharge state. The lowest temperature achieved by this method was in reality the highest possible efficiency obtained and in some cases I found 70% was enough instead of the recommended 80-85%. When properly charged you will see a few bubbles swirling around in the site glass or even a milky appearance which is normal. Other horror stories were the entire flushing of the system because it was thought that you had to remove ALL of the R12 mineral oil because the R134 oil was not compatible in any way shape or form but later Polyolester oil came out and is compatible with small amounts of the R12 oil and compatible with ALL PAG type R134 oils so this is all I kept on hand and if memory serves correct it could even be used in an R12 system. Compressors on the shelf could be filled with Poly oil for both systems. It got to the point that a 30 pound jug of R12 was $1500 so it was cheaper to convert to R12 but in reality that was $50 per pound not $80. But then $50 was worth a lot more back then than $80 today LOL
Another point about R134 is it leaks out of old style hoses a bit more so the story goes due to a smaller molecular characteristic and would be like using Nitrogen in tires instead of compressed air. Barrier hoses are now used and I think they have cotton braided barier hose now that can be used instead of the smooth rubber hose.

[Jack Bowser]

R 12 is still around.

My local Radiator shop still has it.

It's $80.00 a pound now however so you want to ensure there are no leaks in your system before putting it in.

[Jack Bowser]

Thanks. Good information.

I can't see my sight glass because the little window is cloudy. I need to corect that.

I haven't loooked to see how difficult it is to removed the carpeted panel but will put that on my list of things to do.

Keeping the condenser clean is very important and I had not thought of that until mreading this post so thanks again for taking the time to write aall this important information.

[Matt Cashion]

Please post how you removed your sight glass when you do get to it for cleaning. Mine is clear but leaks and I've used large open end wrenches with significant force but have been unable to loosen the flare nuts. I hesitate to use heat for fear of breaking the glass tube inside so I'm waiting to see if someone goes down this rabbit hole and comes back unbroken.

[Don Henschel]

If room permits use flare nut wrenches which are like a box end wrench just for this purpose. Working on mobile AC for years which often contains aluminum and fragile connections and lines I always used the squeeze the wrenches together with one hand method! Slightly offset a pair of wrenches with a slight space in the LOOSENING position and with one hand or if necessary both hands on the pair squeeze the wrenches together! Using a hand on each wrench is quite simply a recipie for disaster because if a wrench slips or the fitting loosens suddenly can result in damage. Squeezing a pair of wrenches together provides much more safer control. I haven't looked at mine for a number of years but some site glasses could be disassembled and if not using something like Brake clean works good as well to clean and if need be force a small piece of cloth through. A dirty or coated site glass is not a good sign and often indicates a dirty contaminated system. Moisture is one of the greatest enemies of AC because it combines with R12 and forms an acid and this corrods components as well. If your compressor has failed a COMPLETE system flush should be performed and the drier must be removed, replaced or sent away to be reconditioned. Also if the system is disassembled in any way, all open connections must be closed off with caps or tape to prevent dirt and moisture from entering, besides why would you leave it open in the first place?
Years ago we were able to use R11 which would be a liquid form at room temperature to flush but this is nolonger allowed being an ozone depleting substance so I use Brake clean now. Some brake clean uses dry cleaning solvent or Perk for short and this also works good but it too is an ozone depleter and is getting harder to find. If using brake cleaner it should be purged out as good as possible using clean dry compressed air and of course after a flush oil must be added back into the system. Typically an ounce or two of oil for the condenser, the same for the evaporator, lengths of refrigerant lines and hoses and of course an ounce for the drier as well. The service manual for AC on these cars will probably have a quantity of oil required for cases like this but as a rule of thumb let's say a condenser or evaporator was replaced due to a leak, and in this case it was remove the original, add an ounce or two to the replacement and install. Don't forget about the compressor as well as the crankcase holds oil as well and this is why the 56 model had the site glass on the bottom. If your site glass is leaking and damaged find a good used replacement or contact a refrigerant parts supplier because there are assortments of site glasses available that could be used. My wholesaler had these, some of which contained a moisture indicator that would change color in the presence of moisture. The ones I had, had a glass the size of a quarter or larger and were intended for replacement or to be added if there wasn't one. I built my own refrigerant recovery unit using a new surplus cooler unit for one of those tiny vending unit coolers which consisted of the compressor, and a small electric fan cooled condenser and used one of those site glasses to let me see if refrigerant was still flowing and of course to alert me if I needed to replace the filter drier contained in the unit. I later purchased recovery units when multiple types of refrigerant came out.
Not being able to see through the glass isn't the end of the world because you can always use pressure readings or if the system is low, recover the refrigerant, check the oil and precisely measure out the 6-6.5 pounds and put that in but first check if the original large Reciever drier is still being used because it is large and is a reservoir. If the system is dirty and a flush is performed concider sending the OEM drier to Classic Auto Air for reconditioning. I was able to purchase pouches of desicant for this purpose so I could cut mine open and replace the desicant and weld it back together. Older GM products had driers that could be opened and desicant replaced so this is why my wholesaler had it.
If your system is empty, or disassembled it must be evacuated as the term goes for placing under a vacuum. The vacuum removes air (which shows up as bubbles in the site glass) and moisture. Water boils under a vacuum and allows it to be removed. An old refrigerator compressor can also be used for this purpose and I used one for years. A refrigerant guage fitting can be brazed on using silver solder so the fridge compressor can be connected to your AC gauge set. Simple tools like this allows you to perform repairs yourself as well.

Now given the price of R12 or the availability if you have a recovery unit like I do, you can recover the refrigerant and store in a proper metal jug and pressure up the system with nitrogen gas if the vehicle is in storage or parked for the winter LOL.
Don't have a recovery unit? Build one like I did ;-)
I used an old upright battery charger on wheels for the housing for the surplus cooler I purchased. The holes in the front for the positive and negative battery cables became the location for my suction and discharge coupler fittings the hoses were connected to and the location of the ammeter became the location of my site glass.

[GAT]

I know this a old post but do you known anyone who rebuilds 1957 compressors? thanks Gary T

[jdsnoddy]

Contact Classic Auto Air
Tampa, FL
(813) 251-2356
https://g.co/kgs/aD62C4

[Don Henschel]

And depending what is wrong with it, depends on whether or not it can be refurbished. 56 and 57 compressors are the same with a mention in one authenticity manual, 56 has a site glass and 57 does not but that means very little depending on what was installed or later installed. The bellows style crankshaft seal is a great determination of whether a compressor can be restored, if available?? If somebody doesn't know what they are doing, and damages the brass bellows on the crankshaft seal, the seal is ruined. If the carbon seal ring has minor wear it can be lapped down on glass and with ultra fine lapping compound IF YOU KNOW WHAT YOU ARE DOING!!!
I did this with mine years ago before the internet and before knowing about Classic Auto Air including using a Jewler's magnifying glass to inspect the carbon ring as I lapped it. Yes it is sealing but if your seal is wrecked you have to find NOS which is very seldom or a good used which are hard to find.
The clutches are harder to locate than the compressors and the Continental division used a piss poor design clutch on the Mark II. Years ago I was strongly warned you simply do not throw the switch on for AC if your engine is running fast such as on the highway because the sudden jolt of this lousy clutch will snap the flex plate spring on the clutch disk and you only turn them on at slow idle and leave it on or shut it off and leave it off until the engine is idling SLOW!
If you want to totally destroy your compressor, walk up to the car with a 1 pound can of R12 and "top it up". Yes you can destroy it because when refrigerant is lost, usually the refrigerant oil is lost with it. Keep adding refrigerant without checking the oil and watch your compressor burn out and pollute the entire system with metal filings as it burns out. This was the fate of mine before I got my Mark II.
You will see an HH Tecumseh for sale from time to time and I saw one for sale a number of years ago from a Desoto of 1955 vintage. I got it cheap enough but when I recieved it, yes it is an HH like on our Mark II BUT the orientation of the fittings and other features is different indicating different flavors of these compressors bearing the HH label. The clutch on this Desoto version? It was 1955 but instead of the crap the Mark II uses, this one has the electromagnet bolted to the compressor like ALL modern units from later instead of the brushes and spinning electromagnet like our Mark II compressor. Because of this design the compressor could be operated using a thermostat instead of the throttle valve to control the temperature.
Due to the crap we have and it's fragile nature is why they are hard to locate.
As for my Desoto gamble, the inside was like brand new with parts interchangeable but I don't have the desire to part it out due to how difficult they are to locate. It is likely rarer than the style on our Mark II.
If you want to destroy your compressor, ship it with the clutch still on🤬🤬. Mine was shipped off to some outfit in Texas who I might add did a shoddy job of restoration, not even replacing the bearings with new along with gaskets hacked out by hand. Dennis Carpenter sells premium gasket sets so why chop out gaskets and I spent the time after obtaining better material and cut my own! They shipped it back with the clutch on the crankshaft. The AC wholesaler who I dealt with delivered it with cores using their truck and then picked it up using their truck. They PROPERLY packed it and Canada Post played football with it. I opened the carton to find the clutch laying loose with the tip of the crankshaft in the clutch. I blasted Canada Post along with my wholesaler and got my money refunded and ended up with a better compressor but with a busted taper tip off the crank. I sent the crank to a machine shop and they built up the end using brass and machined a new taper. When I installed the compressor, yes the pulley turns freely including with a new clutch bearing I also installed but when the clutch is engaged, the pulley has a nasty wobble. The crank is likely bent or not machined true, or the press on clutch hub is stretched out of round and causing the wobble. Since then I got a good used crankshaft and another clutch disk/hub assembly from Classic Air and I will pray the problem is the crank because my front clutch plate has better clutch fiber over the replacement. This or contact them for a hub with a busted flex spring and replace my hub with a replacement.
There is no provision for a clutch puller on these LOUSY clutches. It is called remove the bolt and install one slightly longer along with the washer and by longer, slightly longer so the bolt can be bottomed out only by finger, but leaving the washer to clutch hub slightly loose and while holding the clutch, get an assistant to use a punch and strike the bolt to pop the clutch off.
I did this by myself by supporting the clutch between my legs with the compressor hanging and gave the bolt a sharp hit popping it loose. You sure as heck want the compressor over a pile of rags and close to the floor because if the bolt breaks, the compressor will fall and is why I had a box full of rags below the compressor. This and REMOVE THE BRUSH ASSEMBLY first!! The bakelite brush levers that pivot against the copper rings are impossible to locate and while removing the clutch, the brush holder assembly can get destroyed. Again if you don't know what you are doing, keep your damn grubhooks off the goodies!
I was told years later that, that is what you have to do, to remove the clutch and having the compressor hanging while the clutch bolt is hit will prevent the compressor and the crank from shock and the possibility of bending the crank, damaging bearings and the seal but to remove the clutch. Don't use a claw or gear puller on the pulley as well because it could get bent. I have been working on mobile AC for a number of years and have an assortment of pullers but no provisions were provided on these. No threaded hole in the hub where a puller is used to push against the crankshaft or 3 small threaded holes on the clutch to install a puller to push against the crankshaft. NOTHING except supporting the clutch and stiking the head of a bolt🤣. I have worked with Sanden/Sankyo, newer Tecumseh, York, AC Delco/Frigidaire, Chrysler, and nothing as lame as these clutches😖