A/C R12 removal and refill on older Ferrari

I am calling AL Gore.. What's his address? I have a case of old r12.. That has been sitting on my shelf for years...

He should really go by a shop and pay 50 bucks and use theirs..

 

Take it to a shop with a machine to reclaim it...

IF there is any there it proves there's no leak......it's probably empty and it probably leaks...which will make pulling a vacuum rather a mute point....

Filling with R12 represents about $400.00 these days, he might want to have it in the tank instead of in the air...

 

I would definitely go with reclaim, filter and reuse it, the stuff isn't cheap! Also I wouldn't switch to 134a if he can avoid it.

 

Has anyone used (Freeze 12) yet?

 

Bingo.

 

Check out propane based refrigerants such as DuraCool. I've been using them since late 1980's.

 

Make sure it's not readily flammable --- raw propane IS!
Make sure it's safe for copper tubing --- raw propane IS NOT!

 

Does your friend know at this point if the system has pressure?
As pointed out, if it's still got pressure, then there's no need to discharge the current refrigerant unless parts are going to be replaced. Just add as needed to get proper operating pressures.

But, to the technical point: no, you should not hook your vacuum pump up to a pressurized system and allow the refrigerant (no matter what type) to vent through the vacuum pump. It is only to be used to pull the system below ambient pressure.

 

It's not raw propane but it is flammable along with the 100 pounds or so of gasoline in your car. I used it in a MB for 18 years and in a Porsche for 13 years and in my 328 for 4 years. It takes less than 1 pound to charge a car that normally would take 2.2 pounds of R12.

 

What's wrong with converting it to R134?

My Porsche 928 was converted to R134 and it worked great, my Mondial t aircon seems to work fine with R134 too.

Is there an issue with R134 damaging the system over time? My 928 guy said it may eventually ruin the compressor, and also that it leaks out more easily because the "molecules are smaller". He said he put some sort of lubricant/leak stopper into the system with the R134 to try and reduce the losses.

It stayed working (in the Porsche) for nearly a year, and I believe it is still working 4 months after I sold the car.

 

It's fractionally less functional, thermal wise...no big deal.

 

True. But, then again the fuel (gasoline) containment system is subjected to crash testing performance standards by the DOT ---- the A/C condenser sitting right behind your front bumper is not

My biggest concern would be the corrosive potential of the propane on the copper in the system. The US has recently passed new building codes forbidding the use of copper tubing / fittings in residential and commercial HVAC plumbing carrying natural gas or propane because of this failure mechanism.

 

I have used Freeze 12 for over 15 years. I never had a problem.

 

Ah, if I had not retired.... There were two materials engineers with graduate degrees nearby. We worked for a very successful chemical company where stress corrosion cracking was of utmost importance.

 

All commercial and HD-5 grade propane is required to pass the copper strip corrosion test, ASTM Test Method D 1838 so propane itself is not corrosive to copper.

Natural gas which contains propane (and butane, ethane and methane) can be corrosive to copper. Mostly because of all the impurities (Carbonyl sulfide (COS) gas is normally found mixed with the ethanes as a contaminant) COS gas mixed with any moisture can create hydorgen sulfide gas which is corrosive.

The biggest reason though that they dont allow copper in many localities... is that too many people think copper pipe means water. And cutting a gas line is SO not like cutting a water line.

If you pull a good vacuum on the AC system (which is really done to remove all the moisture along with any other gas contaminant) and use a new receiver dryer (which keeps the system dry) you wont have corrosion issues.

Really, any water vapor in the AC system really degrades the performance of your AC. Too many people just try to flush out their AC with freon and dont pull a vacuum, flushing does nothing to get the moisture out and that creates all kinds of performance issues.

ALWAYS pull a vacuum (<100 microns) before filling any AC system that has been opened to the atmosphere. The vacuum causes the water to boil and allows it to be removed as a vapor. Water is a really crappy refrigerant.

 

All true.

And, the irony is that the "sulphur compound" is actually added artificially to HVAC grade NG & LP to give it a "smell" so that one knows if they have a leak.

If you can get the refrigerant grade of LP that doesn't have the added sulphur, corrosion should not be a big problem.

I would check the MSDS of the "DuraCool" product to be sure what's all in there.

 

IMPORTANT - If he does vacuum out his system do NOT forget to add back oil before putting in the R12. The refrigerant oil of choice for R12 is mineral oil and is available with proper additives. The op states the car is his friends so the amount will be dictated in the friends owners manual.

a compressor oil thread
http://www.ferrarichat.com/forum/showthread.php?t=247886&highlight=ounces+R12+oil

 

Mixed in with your not-flammable R12 is a whole bunch of flammable oil to lube the compressor. The propane might be more flammable, but it's not like any air condo is immune to some excitement.