NO A/C in 104oF weather!!!!!!! - Page 2 - PeachParts Mercedes-Benz Forum

Putty · #16 04-25-2009, 04:28 PM

Ahh, my apologies...let me be more specific...Nitrogen will not have the same pressure/temperature characteristics as ambient air or freon. Its absolutely true that all gasses, even inert gasses, will be affected by temperature...nitrogen is no exception. However, keeping in mind our average earth temperatues and climate...nitrogen would be the best option for refrigeration leak detecting and brazing/soldering.

Nitrogen condenses at its boiling point, -195.8o C (-320.4o F), to a colorless liquid that is lighter than water.

Unless you are repairing your Mercedes on Jupiter of course...

leathermang · #17 04-25-2009, 04:59 PM

Quote:

Originally Posted by Putty

Ive read about using compressed air on here and I dont recommend it. Ambient air is whats considered a "combustable"...whereas nitrogen is a "non-combustable". Nitrogen is dry and its pressure is not affected by changes is temperature. ...

As regards freon...yes R-12 is expensive and not produced anywhere...your best bet would be to find it used (recycled/reclaimed) or in a forgotten garage somewhere...otherwise people have switched to R-134a. Dupont cornered the market on that freon and soon, it too will be gone.

My advice is look into R-420A.

Its like ICOR's "Hot Shot" (which is another great freon) but its whats referred to as a "drop in" freon. It mixes with mineral oil AND Alkylbenzine and can top off your existing charge.

"Sniffer" probes can be rented in some places...I would recommend the R-22 sniff test...its VERY effective and will spot pinhole leaks better than soap.

Hope this helped.

I think you mean ' non compressible'... instead of non combustible...
When used in the Air conditioning world it means it is or is not compressible AT THE PRESSURES WE DEAL WITH IN AIR CONDITIONERS...
all gases are compressible by definition....

I can not find R-420A listed in either acceptable or unacceptable refrigerant lists by the EPA...

http://www.epa.gov/ozone/snap/refrigerants/lists/unaccept.html

http://www.epa.gov/ozone/snap/refrigerants/lists/mvacs.html

Hot Shot is a blend of 4 refrigerants... so it has the drawback in small leaks of losing the smaller size molecules first... thus making topping off less than scientific... one would need to take it all out....and put fresh in...

Important to read this page....very good over all view...
http://www.aa1car.com/library/tr497.htm

Putty · #18 04-25-2009, 09:47 PM

I cant say for sure what the EPA says about using this refrigerant in automobiles, however, I work as a field technician in the HVAC industry and I have topped off R-134a AND R-12 with R420A with great success! The AC unit in an automobile should not be any different

Putty · #19 04-25-2009, 09:52 PM

...and also I would like to add that it is an HFC...not CFC or HCFC...and although I know that the EPA does not allow venting of ANY refrigerant, it is not harmful to the Ozone Layer

JordaanDMC-12 · #20 04-25-2009, 10:25 PM

Ok, went to the mechanic for the A/C and he said that my compressor looks like it still has life in it. So what we are going to do is:

Change some hoses because he said the ones I have on now will not hold anything. He wants to change the oil in the compressor and then recharge it and see if it holds the freon. I would have liked to DIY but I don't know what i'm doing when it comes to this. I'm not getting this done though for a few more paychecks. To make sure I have enough in case it's expensive.

leathermang · #21 04-25-2009, 10:53 PM

I think that is a good decision...
You should still do all the research you can so you can ' guide' your mechanic to the lowest price and coolest destination....

JordaanDMC-12 · #22 04-25-2009, 11:00 PM

Yeah that's what i'm going to do. Thanks for all the info, suggestions everyone I really, really appreciate it. This forum is so awesome!

I just hope I get A/C before it hits 124oF ugh I hate Palm Springs so bad...