A/C Radiator

Is it possible to swap out a leaky A/C rad on your own, or does this have to be done by a shop. Lately, I've noticed fluid underneath the front of the car in one spot, its almost clear in color. Also, some areas on the fins are shiney/wet. The A/C still works at the moment.

The A/C Radiator you speak of is the A/C Condensor.
The leaky fluid is the freon in a liquid state mixed with a small amount of lubricant..
Legally you are supposed to bring it to a shop where they will evacuate the freon under pressure and store it.
Then you can take the car and replace the condenser on your own and bring it back to the shop, let them put in the amount of freon they took and add any additional that is needed to fill the system properly along with the correct amount and type of oil used and then pay them for that work and to leak test all the fittings you had to loosen.
Other people have been known to evacuate the system by releasing the freon into the atmosphere, replace the bad parts and then bring it a shop for proper servicing of freon, oil and leak testing.

Rickw wrote:

The A/C Radiator you speak of is the A/C Condensor.
The leaky fluid is the freon in a liquid state mixed with a small amount of lubricant..
Legally you are supposed to bring it to a shop where they will evacuate the freon under pressure and store it.
Then you can take the car and replace the condenser on your own and bring it back to the shop, let them put in the amount of freon they took and add any additional that is needed to fill the system properly along with the correct amount and type of oil used and then pay them for that work and to leak test all the fittings you had to loosen.
Other people have been known to evacuate the system by releasing the freon into the atmosphere, replace the bad parts and then bring it a shop for proper servicing of freon, oil and leak testing.

You may be able to work a deal with the shop to charge you less for the refill if you let them evacuate your refrigerant than if you don't.

Albertj

WOW, quick and thorough responses, excellent info guys, Thanks!

FYI, There is another component in the system called the Receiver / Dryer. The freon flows through this unit and any moisture that might be in the system is absorbed by desiccant inside this canister. It is only designed to absorb a very small amount of water in a good clean and tight system so the A/C system doesn't freeze up under normal operation.
Technically if the system is left open for any length of time to the atmosphere this desiccant will absorb all the moisture it is capable of absorbing by the normal humidity in the air. If you open the system up removing these lines to accommodate the replacement of the condenser your supposed to replace the Receiver Dryer as there is no way to dry out the desiccant. The good thing about doing this type of job in the winter as compared to the summer is there almost no humidity to cause a problem. When replacing the condenser just be sure that you have all tools, new o-rings if necessary for the tubes, ready to go, and swap everything out as quick as possible and tighten fittings gently. (they are aluminum tubes).
Sometimes you can get away without replacing the receiver dryer. Part of what the shop will have to do once they get your car back is to hook up a vacuum pump and hold vacuum on the A/C system for about 20 minutes. This does three things, it makes sure there are no leaks, it further evacuates the system (draws any remaining freon, oil and moisture) and provides negative pressure to help reintroduce freon back into the system so that the car can be started and the compressor will come on with freon and lubricant in it.

Or you could pay the shop to do the whole job and replace the receiver dryer along with the condenser at the same time. This generally isn't a cheap job though.

You need to remember that your A/C system is being worked in the winter as well as the summer. Whenever you put on your front windshield defroster the compressor comes on as the system is trying to draw the moisture from the inside of the window and defog as well as provide heat to defrost as well as during AUTO use of the HVAC system. So if you leave the leak without fixing it thinking you'll be OK for the winter, well you won't. Once you've lost enough freon to where the system drops below a certain pressure internally then the compressor will no longer come on any more and you will start to draw atmospheric air into the system through the leak and you will definitely need to replace the receiver dryer canister when you do the job as it will have absorbed all it can. When you get to that point you should also replace the evaporator orifice tube and filter. It is a small filter that fits inside the tubing just after the receiver dryer. These parts are not expensive and are the correct way to do the job if the system has been emptied for any amount of time. The only problem with replacing these parts are they are a bitch to get to on the Riv, IIRC.
I replaced these components after a compressor failure a few years ago. Again, they weren't expensive and are necessary when you replace a compressor because you don't know if the compressor spit anything out that could clog the small passage ways. You have to consider a similar situation with a leak, which is basically an open system and contaminants as well moisture will find it's way in. The internals of this system have to be very clean for it to work properly. Sorry if I gotten too long winded but there is always more. The FSM is very helpful for description and operation of a system as well as how to remove and replace components.

Based on the info you provided, I am leaning towards having a shop do the whole thing, but going in educated about the process is a bonus. Your post is extremely useful, and I am sure it will benefit many here, thanks. By the way, whats is a ballpark figure to have this job done?

I really don't have a clue on the price of parts and labor anymore.
Your best bet is to get a couple of quotes from shops you can trust.

Rickw wrote:

FYI, There is another component in the system called the Receiver / Dryer. The freon flows through this unit and any moisture that might be in the system is absorbed by desiccant inside this canister. It is only designed to absorb a very small amount of water in a good clean and tight system so the A/C system doesn't freeze up under normal operation.
Technically if the system is left open for any length of time to the atmosphere this desiccant will absorb all the moisture it is capable of absorbing by the normal humidity in the air. If you open the system up removing these lines to accommodate the replacement of the condenser your supposed to replace the Receiver Dryer as there is no way to dry out the desiccant. The good thing about doing this type of job in the winter as compared to the summer is there almost no humidity to cause a problem. When replacing the condenser just be sure that you have all tools, new o-rings if necessary for the tubes, ready to go, and swap everything out as quick as possible and tighten fittings gently. (they are aluminum tubes).
Sometimes you can get away without replacing the receiver dryer. Part of what the shop will have to do once they get your car back is to hook up a vacuum pump and hold vacuum on the A/C system for about 20 minutes. This does three things, it makes sure there are no leaks, it further evacuates the system (draws any remaining freon, oil and moisture) and provides negative pressure to help reintroduce freon back into the system so that the car can be started and the compressor will come on with freon and lubricant in it.

Or you could pay the shop to do the whole job and replace the receiver dryer along with the condenser at the same time. This generally isn't a cheap job though.

You need to remember that your A/C system is being worked in the winter as well as the summer. Whenever you put on your front windshield defroster the compressor comes on as the system is trying to draw the moisture from the inside of the window and defog as well as provide heat to defrost as well as during AUTO use of the HVAC system. So if you leave the leak without fixing it thinking you'll be OK for the winter well you won't. Once you've lost enough freon to where the system drops below a certain pressure internally then the compressor will no longer come on any more and you will start to draw atmospheric air into the system through the leak and you will definitely need to replace the receiver dryer canister when you do the job as it will have absorbed all it can. When you get to that point you should also replace the evaporator orifice tube and filter. It is a small filter that fits inside the tubing just after the receiver dryer. These parts are not expensive and are the correct way to do the job if the system has been emptied for any amount of time. The only problem with replacing these parts are they are a bitch to get to on the Riv, IIRC.
I replaced these components after a compressor failure a few years ago. Again, they weren't expensive and are necessary when you replace a compressor because you don't know if the compressor spit anything out that could clog the small passage ways. You have to consider a similar situation with a leak, which is basically an open system and contaminants as well moisture will find it's way in. The internals of this system have to be very clean for it to work properly. Sorry if I gotten too long winded but there is always more. The FSM is very helpful for description and operation of a system as well as how to remove and replace components.

In comparison to the cost if there is a problem, receiver-dryers are *cheap* - if you can please just replace the thing, it will save you hassle down the road.

Also, if your A/C is noisy (gurgles) probably the screen on your orifice tube is gone. Plan to replace it as well, But Do Not Let The Repair Shop Install The Cheaper Orifice Valve. Put in the variable valve, relatively speaking it is way more expensive, but as a percentage of the price of the AC work it's Cheap and absolutely worth it. Look on the RockAuto.Com site - for your car, in the Heat/Air Conditioning listings there is a line, "orifice tube" and if you open it up you will see there are some tubes for about $1.25 to $2 bucks each and some for $25 or more called "optional automatic adjusting orifice tube." THAT is what you want. Most likely the Delco 1550120/Four Seasons 38902 will work fine unless you routinely see ambient temps above 105 deg. F; if so you'll want the most expensive one, the Four Seasons 38904.

The major difference: the variable orifice tube has a mechanism that varies the size of its opening depending on system load. This works to maintain close-to-optimal low side operating pressure. Kind of comparable to an air pressure regulator. The thing is, the Riv's air conditioner runs just about all the time unless you use the 'vent' setting on the HVAC controls. This reduces condensation in the car, and for the Riv is a very good idea. Since your A/C runs just about all the time, the variable orifice should cool better and save you money, no kidding. It improves AC efficiency at idle, and city traffic fuel economy without any highway economy penalty at all. Admittedly, the efficiency pop is bigger with the Aurora (which used a 'cycling clutch' system with reciprocal compressor rather than the Riv's rotary compressor) An interview with the guy who invented the thing (Richard Kozinski) is here:

http://www.imcool.com/articles/aircondition/VOV2.php

If I am not mistaken the Riv comes with one of these suckers standard. The fixed orifice *will* work don't get me wrong, but *definitely* does not work as well as the variable orifice. By the way for those of you with Vintage Buicks - when you change your R-12 system over to R-134A, the way to get it to cool right at idle is to install a variable orifice tube when you do the conversion.

And if any of you find inaccuracies in this post please point them out/make corrections.

Albertj

Albert,
Thanks for the Link and the insight into the Variable Orifice Valves.
Good info.

Yes, thanks so much for that info Albert!