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400mag

56 olds 88 factory air conditioning

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I have 56 olds 88 2-door sedan with factory air conditioning, and was wondering if any one knows how to hook up the temperature control and and other controls. I have it all, but I'm not quite sure how to hook it all up. All the wiring and stuff like that is hooked up but not the controls. All the air hoses are hooked up to the vents and such. I am just in alittle bit of a twist here. I have a shop manual, but cant find out how to hook up the controls. If anyone knows anything about it, I would be so appreciative.

Thanks

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Edited by 400mag (see edit history)

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hi, are you asking how to hook up the control cables ?, there are three control cables shown in my 1955 oldsmobile air conditioning manual, two that are routed together, go the inner and outer valve levers, a third control cable go to the recirculating air valve, the two valve levers are near the windshield wiper motor, and the third cable should go to the driver's inside part of the firewall. do you have the 56 olds a/c shop manual ?, charles coker, 1953 pontiac tech advisor.

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I have a 56 olds shop manual, but it's an original one and on alot of pages it's getting hard to read. I am currently looking for one that's in good shape and a good price. There probably is a diagram in it, but not that I could see. I must be missing some of the hookup under the dash, the guy before me couldve taken some stuff from it. I have all the air conditioning stuff under the under the hood like compressor and the condenser. Thank you for replying so quickly. I will look to see if I find anything for hook up.

Thanks

Edited by 400mag (see edit history)

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hi, you'll find that most of the makes of cars back then, will have a different manual, covering just air conditioning. charles coker, 1953 pontiac tech advisor.

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The 55 and 56 are nearly the same as far as cabling and controls go.

If you need more help, I will get you a copy of the parts book picture.

You should have both the shop manual and the parts book for the year of the car for most complete info.

But the 55 a/c is covered in a separate manual and the 56 is included in the shop manual but the control hook ups are the same for 55 and 56.

Ron

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I just bought a new manual, and see the hook ups in the book. I think I'm missing some of the hookup under the dash. I can hook some of it up, but not all of it. Does anyone know where I can buy some of the a/c parts. If you do that would be great. I am restoring the car originally, and want it to work.

Thank you for all the help, I apreciate it.

Thanks,

Eric

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hi, you might call turner's wrecking in fresno,ca., ctc auto ranch in denton,tx., desert valley auto wrecking, phoenix,az., join the oldsmobile club, and put a want ad in the club's newsletter. charles coker, 1953 pontiac tech advisor.

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Hi,

I have two 56 88 with factory air.

I can answer most of your questions about the a/c systems on these cars and I have owned them since 1970.

One I modified in the 71 or 72 to use the A6 compressor and I can tell you what I modified if you are interested - all was done to enhance the cooling in the 110 degree Texas heat and city traffic.

The other is stock a/c.

Per your original question about the bowden cable hook up to the a/c unit and the control.

The control is a single lever and operates three cables. If the cables were left attached to the control switch which is the way I have done it in the past - then here are some comments/instructions to hook them up to the a/c unit.

If you look at the three cables it should be obvious due to weathering that two cables are darker than the third cable. Those two weathered cables have different lengths. The longest goes to the hot bypass valve and the shorter to the fresh air valve both which is on the outside of the case just inches from where the cables come through the firewall. The third cable goes under the dash to the recirculate air valve. I would remove the cables and oil them to prevent breaking the lever on the control unit and control units are EXPENSIVE used. With the cable off - chuck a loop of one end into a variable speed drill and spin the cable slowly while oiling the cable and working it in and out. They must slide freely.

The 56 parts book has a good picture of most of the cabling. I can supply that if you still need help.

Now for some pitfalls of using the a/c without rebuild it. The insulation used on the inside of the case is most likely flacking off especially on the air valves or doors as some call them. This leads to poor sealing especially on hot days. These old units were good but not great on hot days especially if the weather stripping on the car doors is not soft and fuzzes on the door glass are worn. Both are major sources of loss of cooling and hot air leaks. Also the butterfly valve on the heater likely is not sealing either and that plus hot water leaking through the heater core from a faulty heater valve is another major heat leak and will burn your feet in the summer. You will also need the rubber drain tubes to control air and engine fumes on the a/c unit and heater.

The compressor seal is likely bad or marginal at best. This has allowed water to enter the system and the dehydrator/receiver really needs to be rebuild but in case of money issues these things need to be flushed until clean liquid comes out the lines, the receiver, the condenser, and the evaporator. Also now is a good time to put a kit in the hot-bypass valve and check for internal rust. On the compressor, the oil plug needs to pulled and the oil drained into a clear measuring cup. You will find brown milky oil most likely but what you are really looking for is any metal debris in the oil. Stick your finger in the oil and feel around for any trash. If none was found - your Lucky - if found - compressor likely is bad or is going bad and will be noisy. Pour some flush in the compressor and slush it around. Drain it and examine for trash. Repeat until clean. Get a new seal or have the one in the compressor rebuilt - replace the o-rings in the coil housing and where the rear plate bolts to the compressor. The clutch bearing needs to be checked for roughness and being dry. These bearing are no longer made so save what you have even if you find a nos bearing. Throughly clean the exterior of the bearing until you are sure it is clean. Then clean it the second time to be 100% SURE. Put it in a bearing packer and press in new grease and flush out the old grease. Then use an air hose and blow about 1/3 of the bearing to get rid of excess grease.

But it all together and lub the fittings with mineral oil. Put the pag oil in in the quantity specified in the manual if going 134. Oh yes, if you do not rebuild the receiver and you use 134 - the drying agent will turn to dust and chew up the compressor. I do not know if that is true or false - I just read it some place and wanted to pass it along. To dry out a "wet" dryer - bake it in an oven for 2 or 3 hours not to exceed 300 degrees Fahrenheit - take from oven hot and install hot to keep the water out - do on a dry day - not rainy and then vacuum over night and check for leaks. If you go 12 then use mineral oil instead of pag oil. Adjust the hot bypass valve 3 or 4 pounds lower if using 134 - read articles on adjusting poa valves for the correct pressure.

I would also rebuild the blower motor and oil it. It has been a while and they are not off the shelf items any more. A stuck motor can burn out the speed resistor before the fuse will blow.

There are some search engines that will broadcast you needs for parts and I have found it most helpful to locate parts. The plastic manifold was non existent in 1972 when I tried to buy a new one - the plastic even in the new ones had crumbled to a million piece when you touched it. I made one out of a metal can and insulated it with friction tape (best thing I could find in 1972). A/C works great while you moving - not so good at idle - but I did solve the problem with gm parts.

If you have questions - just ask.

Ron

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Another comment on flushing - if you use a flush - then a vacuum for 24 hours is needed to "boil" the flush and moisture out of the system - this is important as any flush left in the system - takes away from cooling and thins the oil that the compressor will not be able to with stand.

Also if you flush - rotate the compressor by hand a few turns every few hours to get the flush trapped in the cylinders. Also rotate the compressor before charging - the coil needs voltage to do this with the pulley or a wrench on the shaft nut.

If you do 134 - get another condenser and put them in stacked and in series with the compressor hot gas going into the inter condenser and the output of the inter condenser to the input of the outer condenser - more cooling at idle - looks more original - sight glass charged until clear and add 2 more 12 ounce cans of 134. Do not use the sealer and other fancy 134 as it will plug up things. Speaking of which - check the inlet strainer of the expansion valve for rubbish.

Ron

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Okay - one final comment about any old car a/c. If the metal air outlet nozzles sweat during use (you have driven for 10 or 15 minutes and they are wet) then you have an outside air leak or a window open or not sealing correctly - true for any GM/AMC/Ford/Chrysler factory air system. They went to chromed plastic vents to solve the problem rather than fix the problem and that is also the reason the chrome on the plastic does not last forever.

Ron

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Don't forget to clean and lube the filter.

Also the pictures of the 55/56 dash cabling - I wanted this thread to be reasonably complete.

Ron

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Forgive me resurrecting an ancient thread on my first post here... Does anyone know how to disassemble the in-dash factory A/C vents on the '56 Super 88? I would like to take them apart to have them re-chromed. Thank you!

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On 9/3/2019 at 4:28 PM, Dad Was A Racer said:

Forgive me resurrecting an ancient thread on my first post here... Does anyone know how to disassemble the in-dash factory A/C vents on the '56 Super 88? I would like to take them apart to have them re-chromed. Thank you!

if they are similar to the dash outlets on 1954 pontiac factory a/c (1st in the world to have up front in dash a/c) you have to remove the flex hose and then loosen the large nut that fasten the outlet assemble to the dash. i took the outlet assemblies apart to clean, paint, glue in new felt runners for the chrome jet nozzle ball outlet to float on. 

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