A C Mistake Made Today

[tractorman86]

IMHO 55lbs is kinda high for R12 we usually run 35-45 in our stuff. if you can get ahold of CRC brakleen in the five gallon buckets it is the same as a lot of the flushes.

 

[david85]

I've heard that propane can replace R-12 with satisfactory results, but I'm not sure about the orifice valve size??? You don't need a license to buy propane and you can vent it safely.

But even with this stuff, you still need air passing thru the condenser...;p

A little late, but I can comment on this.

I've experimented with propane, butane, and isobutane. Propane will burn out the compressor because the head pressure is way too high. However, I was able to run high altitude camping stove fuel, which is a mix of all three. It did work, but by then it became clear that my compressor was shot because the hot and cold side of the compressor would bleed back when the compressor shut off. I had to completely tear down the AC system and blow solvent through everything to make sure it was all clean when I put the new compressor on. The orifice tube was completely clogged with the "black death" crap.

In reality, I suspect most of the damage was done before I bought the truck since I know it was tampered with by the PO (he didn't seem to want to elaborate ).

The product called DuraCool that I mentioned earlier is in fact a mixture of propane, butane, and isobutane along with other "additives", as they call it. Its a hell of a lot cheaper than any conventional refrigerant, and I don't need a license to buy it. It worked perfectly from day one and will work with PAG or mineral oil and can be dropped in over R12 or R134a (but thats illegal). I can't quite remember, but I think it only took about 2 cans to get the system to work in my truck. Its also less leak prone than R12 and WAY less leak prone then R134a.

I know there seems to be a lot of fear with hydrocarbon refrigerants, but its not really much to worry about. The amount and pressure of this stuff is not enough to sustain a fire even if there was the right conditions for an explosion in an accident. I would be more worried about what would happen with R134a if it ever gets hot enough. Products like this are the norm over in europe.

 

[tractorman86]

explosion isn't the biggest worry, we had some of that stuff and a leak on the hose to the condensor kept my dad's 92 7.3 running for about a minute or two and you could barely hear it, emagine if it blew a line and quickly released all of the "freon" it could blow your motor as it is pushing it on top of a honda.

 

[bob_442]

Most of you don't know this so I thought I would share. You can drop in other R12 replacements besides 134a. I have been using R409a for years. It acts just like 12, pressures are about the same. Charge liquid only due to being a blend. You must have an EPA license to buy it will be the draw back to the public, but if you have one give it a shot. Down side number two, 30# canisters only, no small cans. I always have it around, so no big deal for me being in the commercial refrigeration business. ANyway, just thought I would share that with you. If you are close to me, I am in Hollister Ca, I can give you a shot of it at my cost if you need. You come to me though if you need it. I can't buy you a jug though it is against the law for me to do so.

Are you referring to Autofrost, which I think is also R406a?

Bob

 

[RLDSL]

409 gets cold as heck, but it's better suited for rigid line systems and sealed compressors. If you try to use that stuff in an automotive system, it had better be seriously tight, because that stuff will very quickly find leaks that even r134a can't seep out of.

 

[DragRag]

I havn't had a problem yet, and why would it leak faster? It's all liquid and the head isn't really any higher, it not any slipperier then 134a or 12. I have been working with this stuff for 13 years now, and I do use a different PT chart of course when checking super heat, but it is very close in pressures. As a matter of fact, on a pressure controlled system, the low side pressure switch adjustment is no more then 1.5psi higher then R12 equipped systems. Rigid or not, if you have a leak, doesn't matter what gas is in there, it is coming out.

 

[DragRag]

Are you referring to Autofrost, which I think is also R406a?

Bob

R409A, Hot Shot, MP66, MP39 just to name a few, there are more of them, and they are usually brand specific.

 

[bob_442]

R409A, Hot Shot, MP66, MP39 just to name a few, there are more of them, and they are usually brand specific.

I've been using autofrost (R406A) for a few years now, and have been generally happy with it. It is a bit colder than R12. I have seen it leak out of some systems quickly, but I didn't turn around and fill them up with R12 to check and see if it didn't leak. It is likely that these systems simply had leaks.

Bob

 

[bob_442]

I've heard that propane can replace R-12 with satisfactory results, but I'm not sure about the orifice valve size??? You don't need a license to buy propane and you can vent it safely.

But even with this stuff, you still need air passing thru the condenser...;p

No, propane does not work very well. It doesn't have anywhere near the heat capacity that, say R12, does. When I tried it, on a summer evening,
it got really really cold at the vent -- 20 degrees F. The next day though, it was more like 60 degrees. That night, it was back to 20 again.

I also tried butane -- the stuff made for cooker stoves. The pressure was so low I had trouble adding very much of it to the system.

 

[david85]

No, propane does not work very well. It doesn't have anywhere near the heat capacity that, say R12, does. When I tried it, on a summer evening,
it got really really cold at the vent -- 20 degrees F. The next day though, it was more like 60 degrees. That night, it was back to 20 again.

I also tried butane -- the stuff made for cooker stoves. The pressure was so low I had trouble adding very much of it to the system.

Nice to know I'm not the only one to admit trying it

 

[bob_442]

Vent a cloud of propane under the hood on a hot day and you will have a runaway diesel. really not good if you are sitting in traffic and have an automatice. The truck will simply run over whatever is in front of it.
Ken

I wonder if this always has to be the case. I mean yes, if the engine is running and the key is on, the propane will happily power the diesel up. But if the key is turned off, will the cetane number of the propane be low enough to prevent ignition? I know propane has a good octane number, which means it has a bad cetane number. Mind you, I'm not looking to test this out. I'm just theorizing.

On the other hand, maybe the oil misted out with the cloud might serve as the compression ignition source.

Bob