The air conditioner in my 1984 245 has been non-operational for at least 15 years. I vaguely remember that it would not hold a charge and, because of its overall dismal performance, I never bothered to have the system repaired.

I have recently moved to an area where it is very hot at this time of the year - triple digits for most of July and August and high 80's right through October.

What is involved in converting the system to r134a, and what would it cost do to the conversion assuming that I do all of the labor?

Are there compressors that are more efficient than the stock compressor? It has been a long time, but I believe that the car came with a York compressor.

I've also read that Volvo installed a pusher fan on the engine side of the evaporator starting in the early 1990s. I think that this is a worthwhile modification. Has anyone done it?

Finally, any wisdom on tinting the rear windows in a wagon? There is so much glass in this car that it creates a "greenhouse effect" and I think that is a large part of the problem.

I charged the system with r12 and it "kind of" works. With ambient temperature hovering in the mid 90s, I am getting what I guess is high 60's air from the vents....after letting it run for over 20 minutes. This is a definite improvement. I would hazard a guess that the temperature in the driver's seat is around 70 - still 25 degrees cooler than outside, but even cooler would be better.

I think that I would be a happy camper if I could get the air, at the vents, down to the high 40's.

Thank you for all of the responses - I hope this is helping other folks, too.

Silly question, but did you put a vacuum on the system and leak check it before charging it? With all teh air out of the lines, you should be getting a bit colder duct temps than that.
I hate to say this but if its been empty this long, the orings wil be all dried out and the charge is likely to go hissing out rather quickly, The rubber hoses and orings depend on the refrigerant being circulated( as does the compressor seal ) to carry the compressor oil through teh system in a fine mist and keep all the rubber parts sealed . if a system sits dormant , the orings are the first to go, then the compressor seal and then teh hoses deterriorate on the inside if left long enough.
As far as replacement compressors, that york is actually a pretty good compressor, before teh rotory comps, it was a standard for heavy duty applications, it was basically discontinued because it was noisy and induced a massive load on the engine of whatever it was installed on, but as far as cooling, its a pretty stout compressor. I generally upgrade the DK and sanden 508 compressors on the later models to a sanden 709 but a york would require custom brackets, you would get better performance and less engine load out of a 709 but would be a bit more work on that model. If not familiar with ac, it would be simpler to just get a replacement york for that car, or if teh system has just leaked, just get a new seal installed in it and have it checked out, chances are the compressor is fine, those things are stout.
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-------Robert,:'00 XC70. '95 960, '93 940t, '90 240 wagon, '94 940SE, '84 240 diesel (she's sick) , '80 245 diesel, '86 740 GLE turbo diesel, '92 Ford F350 diesel dually

If you did not at least replace the two schrader valves be prepared to loose all that R12 in pretty short order. Amongst other concerns, this weak point in R12 systems was one of the major upgrades when they went to quick-disconnect fittings for R134A. I am not sure if it was the automitive environment, quality of the parts or other factors but one or both of the valves invariably leak if the system has been depressurized for any period of time.

And HVAC proefessionwill have a handy little tool for replacing the while still leaving almost all of the freon in the system and I am sure they are available to the rest of us but I have just never looked for one.

The seventies is not too bad in the overall scheme of things. Glad to hear you are getting some relief!

Almost all refrigeration calculations for load and dissipating that heat loads are done with a temperature change of 30 degrees of change. This is BTU's removed, Of course,it is a rule of thumb again. You can also use a rule that the refrigerant temperature at the suction valves will approximately 10 degrees colder that that outsides of the tubing on the evaporator.

Actually when it come to air condition say like malls and stores they do not want people to walk in from outside and be subjected to more than a 30 degree change of temperature.
Air conditioning means to condition the air by cooling, heating, humidifying, dehumidifying or filtering.

Air temperature change can cause people to faint coming in or going out.
People with blood pressure issues whether they know it or not can find it out the hard way. If you think about it, that is the number one reason ambulances are called to malls in the summer time. People are usually there for coolness on the cheap and are older or less healthy because their bodies respond slower.

If a car was as cold as you think you would like when you pop the door you could almost feel a your breathe being taken away because the hot air is naturally thinner air!
This stuff is a double edge sword, literally!
Cold conditioned, refrigerated air can also be lower in humidity. When you open a door and there you are to deal with hot humid air, like in the south east.
You have no perspiration on the body to prepare you for the sudden change in heat. you have no cushion to start keeping you cool and if you are person that is slow to perspire, then, there you have an overheated human.

Work on the other things I mentioned and you could decrease the time to do a cool down. Thecompressor will work less and save you some gas, it is the theory anyway!

Phil

Everything thing you mention affects cooling.

Putting on an external fan will increase the effective size of the same size condenser which if the heat from evaporator will be removed better.

The compressors i suspicion on both cars are about the in capacity. The newer swash plate units are more compact due to their design in which they divided it capacity across six smaller piston with shorter strokes. Where as the York uses one or two pistons so consequently the reciprocating mass is greater. This requires energy to constantly reverse which makes one believe it is less efficient even though pumping capacity could be the same or more. A person would hope that the change to swash plate designs was an improvement but it does not mean that York compressors cannot do the job at hand.

I personally have found on my cars (a 84 sedan and a 86 wagon) that an adjustment, movement, of the thermal expansion valves sensing bulb can increased the evaporators effectiveness. Usually an inch or two farther down the evaporators tail pipe, in its proper posion around the pipe and will allow more liquid droplets of refrigerant to be exposed inside the evaporator. Another trick is to place a thin insulator (plastic) between the sensing tube and the tail pipe tubing.

I call it tuning or balancing the system. If done correctly you should be able to feel comfortable with the thermostat at the three to four "O" clock position. But then again feeling comfortable comes in different flavors for different people and anxieties.

You want more refrigerant to keep the low side pressure up to prevent freezing and enough liquid to flow away the heat. Like water on a fire but not wet the ground beneath it! You do not want liquids getting back to the compressor as they will not compress.

Just for a rule of thumb the R134 is about ten percent less efficient in moving heat than R12 everything being equal. Most people might say you do not run anything at 100 percent all the time which could be a valid point.
I am watching out for the stats on its replacement, R1234YK coming out on new cars! It has a smaller CO2 foot print, when improperly used!

Having a 245 with a sedans A/C is a disadvantage but can be modified. On a sedan you do not cool the trunk. On the 245 a clear vinyl curtain could be placed in a free standi frame (like a dog panel) behind the back seat. It would effectively reduce the total space back to a sedans capacity.
Might be less expensive to make than tinting windows and it can be used seasonally!
Insulating the roof under the head liner with stick on panel insulation might help and would be quieter in the rain! Big deal but its an idea.

All or any one thing can improve things.

They use to say that even washing your Harley-Davidison will improve it and you do not have to check with the Smithsonian, for permission, like Harley was accused of in years past! (:)

Phil

I'm going to tell you right now.

I know of what I speak because I drove a 245Diesel in Las Vegas for several years.

If you do not get your windows tinted, any work you do to the A/C will be for naught. With so much glass, even a top-notch A/C system has trouble keeping up with the desert heat. The 245 never had, and never will have a top-notch A/C system.

Tint those windows darker than you think is practical. I recommend 5%, or even 2% on the back door windows and cargo side windows. No less than 20% on front door windows and tailgate window.

Driving around Las Vegas without window tint makes as much sense as summer tires in Anchorage in January.

I'm going to tell you right now.

I know of what I speak because I drove a 245Diesel in Las Vegas for several years.

If you do not get your windows tinted, any work you do to the A/C will be for naught. With so much glass, even a top-notch A/C system has trouble keeping up with the desert heat. The 245 never had, and never will have a top-notch A/C system.

Tint those windows darker than you think is practical. I recommend 5%, or even 2% on the back door windows and cargo side windows. No less than 20% on front door windows and tailgate window.

Driving around Las Vegas without window tint makes as much sense as summer tires in Anchorage in January.

IMHO onkle udo is correct on all counts. First, find out what is wrong with your AC. Pour in a can or two of substitute R12 and see if the system even works and how long it lasts. Get a vacuum test and check for leaks. Use a little spit on the end of the schrader valve and see if it leaks (common and easy to replace).

Install an electric fan, even your engine will like that.

Get your windows tinted, that does work.

If you have a dark colored car, well, that makes it hotter than one with a white top.

After parking the car in the sun, when you go to get in, open all of the doors first to let out some of the 180F heat.

If you end up needing to spend a lot of money to fix your car's AC, instead why not consider buying a "summer beater"? A ****box with working AC and use it during the summer only?

The reverse is common practice in northern states. One buys a "winter beater" to drive in ice, snow, slush, salt etc. Saving the good car for mild weather, snow-free weather....:)

There is nothing really wrong with the compressor except that is saps an inordinate amount of power from the engine and it is noisy. The York/Tecumseh compressors are prety stout, checp rebuilt and stone-simple.

The rest of the system is just not sized or designed for actual places that have summer.

Your best bet is to find some of the old threads on the various replacement parts (hoses, o-rings, schrader valves) that will be shot after years of non-use and age. Flush the condensor and evaporator and replace the compressor with a rebuilt one (because they are SOOO cheap). Of course an overnight vac of the newly assemble system is a must.

That is your baseline and you can decide which refridgerant to use from there. I will not go on my rant about hydrocarbon refrigerant (works great FWIW) but there are R12 replacements that are legal in the US, Recycled R12 is available legally and R134A is available.

My wife's 1981 245 with the same system as yours was recharge with Freeze12 when we just wanted to see if the AC system even worked...no flush, one schrader replaced...nothing else. It was blowing about 44 F at the vents idling on a 90 degree day. Not stellar 1970's GM AC performance but not bad. The car got taken out by the tree limb before we could test the long term effectiveness but with the steps listed above, likely you can acheive decent performance for under $1K.

IMHO - Don't bother converting to a R134a system. I did that on my 90 244 and it was not worth it. Personally, I would fix the problem(s) with your old system, spend a little more and recharge it with freon. That isn't the most environmentally friendly thing to do but I think it is your best bet at getting a reasonable AC system in that car. I understand that R134a is almost as expensive as freon now. Maybe a pusher fan would help? Older 240's AC systems are pretty weak. Almost useless....

I have some of the same questions regarding my own '84 245ti with non-working AC - but can answer one part of your question(s). A "pusher" fan does just that -- mounted in front of the condenser it pushes air through it. I had/may still have a fan and brackets for the 240 series - I've heard it called a "Florida fan". A fan doing that can make a big difference in the system's efficiency.
The later style compressors may work better than the York but having serviced many new (1960's - 1970's) British, French and German cars that came with the York I know they can make a car cold. So I don't know if going through the trouble (if possible) to install a later system with different brackets, pulley arrangements and hoses is worth the trouble/expense over a properly working York system. -- Dave