Recharging AC on 79 Fleetwood Brougham question.

[guyrobert]

Thanks again for all your help, yes I am in Vancouver and as mentioned finding a local shop that will work on older cars is difficult if not impossible. The R12 is IG-LO DuPont Freon 12. I will try to get the gauge on it this weekend and see where the pressure is at.

[Fixedagain]

Guy, There is only one way to determine your systems health. Connect your gauge set, start the car & turn the Climate Control on with the temp dial on 60 with the blower on high. Look at your gauge pressures. You have a cycling clutch system. When cooling properly you should see the low side reading drop to about 27 lb then the compressor will shut off. Watch the low side gauge & the pressure will gradually rise to around 40 lb then the compressor will 're engage & the process starts over. Depending on the outside temp you should see about 170 lb on the high side. If it's cycling very rapidly, like every 5 seconds or less, your likely under charged & you will see low pressures on your gauges. If it's over charged the compressor won't cycle & you will have high readings on both gauges. A restriction in the high or low side will show as an excessive reading on that particular side of the system. This is a very easy check you can do yourself. Let me know what you see.

[Tom Hoczyk , CLC 14044]

Lots of good information here.  I'll just add a couple thoughts and observations.  I personally have a stash of R-12 so I have no plan to switch to 134a.  Remember, however,  that the R-134a molecule is smaller than the R-12 molecule, so the old style rubber a/c hoses will actually allow the refrigerant to escape through the hose itself.  Current hoses are made of Parflex, essentially a type of braided plastic, from which 134a won't escape.  I was very chummy with my radiator-a/c shop so they allowed me to come in and custom build a set of Parflex system hoses even though my plan was to continue with R-12 on my '60 Cadillac.

Also remember that the pressure curve of R-134a is such that, to cool and function as well as R-12, the condenser SHOULD be made larger than the equivalent R-12 condenser.  I have had numerous friends making the refrigerant change, only to discover that the larger condenser was a requirement to give them cooling satisfaction.  The smaller (standard R-12) condenser did not shed enough heat, thus did not lower the refrigerant pressure in the system, and the refrigerant (under this higher pressure) found every opportunity to find a tiny area to escape from and it did so.  I hope my information is helpful.

["Cadillac Kid" Greg Surfas 15364]

Tom,
It is not the size of the refrigerant molecule, but the permeance (the ability to pass through) with respect to the materials used for R-12 that is the reason for the change in hose materials.
Greg Surfas

[R Schroeder]

What about the programmer, and the temp dial. Maybe those are not working.
Programmer could be in the heat mode.
Roy

For the record, my 78 took 3-3/4 pounds of R-12. That is what is on the car sticker. Blows out at 40 degrees from the vents.

[guyrobert]

Update, Had some time on the weekend so I hooked up (tried to hook up) the gauges, one of the end fittings is damaged and I was unable to get a proper reading. There is still coolant in the system because when the Schrader valve was depressed briefly there was a strong short blast of R12. I am leaning to Roy's suggestion that it maybe the programmer. I have picked up the manual and will go over it to see if there are some tests I can run to determine this.
It is going to the garage on the 29th to deal with the Antenna (cord is broken), needs a tune up (still has the original spark plugs)!
The dash will get pulled and the 1 inch crack repaired and the headlights aligned.
If I can't sort out the heat issue with the programmer that will get addressed too.
Will post another update soon.

[Viator Trudeau]

Hello,   to flush condensers, evaporators,- what do you use for the flushing material.  Do you isolate the piece then flush the stuff thru??

V. Trudeau

[TJ Hopland]

You do want to take apart as many fittings as you can.  There are things you don't want to flush or can't flush like the compressor, dryer, and what ever sort of orifice/expansion valve the system uses.    Taking things apart makes flushing easier plus you want to replace all the seals anyway.   

I use a A/C system specific flush product.   Most stores seem to have a fairly inexpensive product like say $15 and an expensive one $45.  The expensive one seems to have worked best for me especially on older stuff.   It also comes in a metal can and has more warning labels on it.   It seems to be pretty strong stuff, even working outside the fumes are strong but you really see the crud coming out.    They all seem to come in just a regular can/bottle.    In AC service tool catalogs there are metal cans that you fill with compressed air that then have a rubber tipped nozzle that fits well into a lot of the fittings.    I have one of these and it does seem to work.   I also considered but could not find at the time what seems to be called an engine cleaning gun.   I think one of them would work.  It adds the cleaner to the air stream.   


http://www.northerntool.com/shop/tools/product_12796_12796


http://www.northerntool.com/shop/tools/product_200355951_200355951

The actual AC thing shoots pure solvent, the engine gun mixes it with air so maybe it would not be concentrated enough?   I stick a chunk of heater hose on the end I'm not injecting the cleaner.  The end of the hose goes into a bucket covered with a towel to keep down splashing.     Wear safety glasses and protect painted surfaces.   
 

["Cadillac Kid" Greg Surfas 15364]

Viator,
Typically the reasons you would want to clean out the refrigeration system would be that it was either left open for an extended period of time, or you were removing ALL the mineral oil (from an R-12 system) as part of the process of changing to R-134a.Some of the components such as the VIR, or an expansion valve must be at least partially disassembled in order to clean them, and others like the condenser will trap residue unless they are removed from the vehicle and drained.
That said, there are several types of flushes on the market, and many of them contain petroleum products. It IS possible for these products to form "gunk" within the system and I personally avoid them. There is a product I use, RX-11   http://www.grainger.com/product/2RZW8?gclid=CJ6e3c2ymcYCFQuDaQodFFYAHA&cm_mmc=PPC:GOOGLEPLAC-_-HVAC%20and%20Refrigeration-_-A/C%20Refrigeration-_-2RZW8&ef_id=U4-qewAABKr5Ulju:20150618135541:sthat is available at refrigeration and air conditioning wholesalers that although quite expensive (about $150.00 for a 2 pound container) is well worth it.
Dryer/Receivers of course need to be replaced, not cleaned, and the evaporator can be cleaned in place, however if the system is such that the internals need cleaning chances are very good that you would want to remove the evaporator to clean the air side as well.
Greg Surfas

[TJ Hopland]

Having a sized compressor is another reason to flush.   

That is some expensive stuff Greg linked to.  I can't quite get to the shelf to see what the last stuff I bought was.   I got it from an shop that does a lot of custom AC stuff, same shop I have make hoses.   The $45 stuff was a quart.   I think the last one I bought was a gallon and was over $100.    What ever the stuff was I got from Napa was mobile AC specific but really didn't seem to cut what appeared to be like a varnish I could see in the ends of the tubes.  If that was what was visible at the ends I can only imagine there was more in the condenser and evaporator.  It even still smelled musty after using it.    With the good stuff that varnish looking stuff came out and the musty smell went away too.   

[bcroe]

You do want to take apart as many fittings as you can.  There are things you don't want to flush or can't flush like the compressor, dryer, and what ever sort of orifice/expansion valve the system uses.    Taking things apart makes flushing easier plus you want to replace all the seals anyway.   

On my mostly R4 systems, I have found the orifice is often full of muck.  Just a couple inch long
skinny plastic funnel with a very fine screen.  They can be cleaned, but are about as easy to just
replace.  Bruce Roe

[guyrobert]

Well the AC problem is solved, thanks for all the help, it was the sensor on the firewall on top of the AC box under the hood. Unfortunately the shop I found had to convert it to R134a as it is illegal to use R12 here. However it does work perfectly now and gets nice and cool. I have worked out almost all the bugs (antenna, small trim missing etc.) but it is having a little issue with slow acceleration now. I had the carb rebuilt and a tune up, but the almost stall in an intersection when you are creeping forward is a bit annoying.

[Scot Minesinger]

Glad you got the a/c fixed and R134 should be fine.  I just charged a 1982 Fleetwood RWD with r134 and it will drive you out of the car it is so cold.

The slow acceleration and almost stall at low speed could be anything.  It is almost impossible to diagnose over the internet without further info.

If it was OK before and your tune/carb re-build was precautionary, then suspicion is not a good carb rebuild.  Every carb shop that rebuilt one for me or my friends messed it up and so now I do them myself - most of the work is cleaning it anyway.  When I say messed up, I'm talking torn gaskets installed anyway, not attaching needle valve to float and etc., not small errors-just blind disregard for quality work.

Otherwise it could be a vacuum leak, timing, vacuum advance, EGR, fuel filter clogged, air filter, and etc..  The good thing about an older car in Canada is that the rubber remains in very good shape due to colder climate.  I worked on a 76 Fleetwood with 50k miles and the original vacuum operated ALC compressor remained fully operational.  Mostly even on a low mileage car the rubber all has to be replaced, but you may be more fortunate than most. This is all presuming it is a Canadian car all its life.

I would take it back to the shop that tuned and re-built carb and get them to fix it. 

[Barry M Wheeler #2189]

I have the same car, converted to R134, ran to Kansas City GN in 95 degree heat and had both cooling and did not overheat. This was with a local general repair shop that did not cost and arm and a leg. Used the same shop to convert my '81 Seville. The little I've driven it this summer it seems to cool nicely. I'll find out next weekend when going to the Fall Festival how good it really is.

[Scot Minesinger]

Barry,

It seems that the 1971 and newer Cadillacs do well with R134.  The 1965 - 1970 are not quite as good.  I have not really figured exactly why, but my theory is the 1971 and newer have more air flow and large condensers.  Never had a complaint about a 1971 or newer conversion to R134 in Washington, DC metro area which routinely is 95'F for weeks during cooling season with high humidity.  However can't say the same about the 65-70 Cadillacs, which are very popular.

[TJ Hopland]

Back in the 70's I never remember being in a GM car and seeing the AC on max.   They must have over sized them a bit then so that is why they can take the hit of 134a without huge issues.   

Maybe its because AC was becoming a more popular option and you needed a lot of airflow to combat all the cigarette/cigar smoke generated with all the ashtrays and lighters the cars had?   Now we just get a lot of cup holders.   Before our cars were killing us because it was easy to smoke, now they help us stay fat with all the cup holders.   

[guyrobert]

Thanks Scot. I had the carb rebuilt by www.canadiancarburetor.com actually it is the 2nd 79 Cadillac carb rebuilt by them. One goes on my 79 Deville Phaeton and the other is on the Fleetwood, I am having an issue with the one off the Phaeton as Darcy the owner says the carb base is incorrect so I will need to find a new base.  I have to go to Europe on business next week but when I get back I'll take the Fleetwood back to my mechanic and see if we can get the carb set up correctly.

[Scot Minesinger]

So you got two carbs for a 79 Caddys rebuilt by the same place and neither works.  If it was the wrong base plate, they should have corrected the problem before it was given back to in exchange for money.  Sorry I'm so cynical on repair shops/carb rebuilders.  I fixed a carb rebuild done in Canada on 76 Fleetwood, and they really messed it up, no "adjustment" was going to fix the rebuild errors. 

Hope you get it straightened out.

BTW I have a modern phaeton too

[mikanystrom]

by the way... for all of you in Canada, sure you can get R134a over the counter there without a license.  You just need to know what to ask for 

http://crc-canada.ca/industrial/products/specialty/freeze-spray-284-grams.html

https://www.amazon.ca/MG-Chemicals-Super-Spray-Aerosol/dp/B005DNQXI2/ref=pd_cp_263_1?ie=UTF8&refRID=A7E8SRFREYCVGQ1XZEYF

Kind of pricey, but you can absolutely get it!

[Barry M Wheeler #2189]

First of all, congratulations on having the good sense to purchase one of the best Cadillacs ever produced. My wife has a 1979 Fleetwood that we have had for some time. I swapped it over to R134 a few years ago and it's working fine.

One of our old time Cadillac LaSalle club members in Seattle is Robert Le Coque. (Father and son) They might be able to help if you wanted to do the changeover in a local shop.

You really need to join our Club. One of my fellow Past Presidents is Richard Sills. Several years ago, he purchased a "worn-out" '79 Fleetwood with 30K. I say that because at about the same time, he found another with 5K. As you have seen, you have many "helpers" to keep your car running correctly on the Forum. Belonging to the Club officially is simply a plus. They do have an active Region in the Seattle area.