recharging an R-12 with R134-a

[runningred92]

If you recharged a thought to already to have been switched over system to r134-a with r-12 what will happen and where should one start repairing if possible?

 

[runningred92]

or recharged a r-12 system with 134-a I think is the way it should have been said.

 

[mr cribb]

I almost 100% certain you can't put 134a in a r12 system. Because when you do the conversion you change out the fittings where you put the freon in at.

What I'm trying to say is they're 2 different sizes and one won't work on the other.

If the conversion hasn't been done, I'm pretty sure the change over kits are almost dirt cheap anymore unlike the 90's when it all first came out.

You would need to clear out the old freon (assuming there is any left) the correct way. Then in the conversion kit there would be step by step instructions to finish the task.

If you have already done the conversion sorry for the excessive explanation.

 

[Jason94sport]

If your going to convert, do it right with all new 134 stuff. Compressor, drier, condenser, lines, orifice tube & o-rings.
Or use freeze 12. It's a damn good R12 substitute.
You can convert using the stock stuff, but it's going to not hold a charge too good. And it won't be as cold.
If you do add 134 to a r12 system, it will kill the r12 system. However, you may be able to evacuate the system fully & then recharge with freeze 12 with no permanent damage. Depends on the condition of that system.

 

[1AJeremyD]

They specifically designed the R-134a system to not hook up to a R-12 without replacing the connections points for the high and low side.

To get a fully functional R-134a system you will have to replace everything except for the piping and even then it should be pressure checked for leaks before hand.

 

[mr cribb]

They specifically designed the R-134a system to not hook up to a R-12 without replacing the connections points for the high and low side.

To get a fully functional R-134a system you will have to replace everything except for the piping and even then it should be pressure checked for leaks before hand.

I'm not disputing anyone that knows more than I do, but I thought the retrofit stuff, you swapped out the fittings and freon? Then if certain items like the drier etc were bad you replaced them at that time.

Maybe I'm just unaware of how it all swaps out. I know when my dad upgraded his ac in a cougar in the 90's EVERYTHING got replaced because that's how the first retrofits packages came out.

 

[surf]

I had mine done About two years ago and I got
quotes for replacement of the entire system (around $900) and for the low cost retrofit which just flushed the system, installed new fittings and recharged with R-134 ($200-$250). I had the shop do the low cost option and it has functioned well. It blows cold enough that once the passenger compartment has cooled down I actually have to turn down the AC because it becomes uncomfortably cold. Is it as cold as original? I don't know but it is cold enough to handle the heat here in Georgia.

 

[Jason94sport]

They specifically designed the R-134a system to not hook up to a R-12 without replacing the connections points for the high and low side.

That may be, but I have seen shops do it. AC work can get real shady in hot places like South FLA.

 

[Maniak]

I've converted two first gen explorers and an 88-f150..

On all of them I replaced the fittings, flushed the system and installed a variable orifice tube and filled it with oil and r-134. On Our explorer which had black death I also replaced the compressor, hoses and condenser. I really should have changed the evaporator, but I didn't have the time or gumption to do it.

~Mark

 

[runningred92]

thanks guys for the info. I finally got a hold of the previous owner and he had the cheap conversion done by a shop. I was adding a can of 134a yesterday and saw the r-12 sticker and got worried but now knowing it has been converted I feel much better now and much colder.

 

[mr cribb]

thanks guys for the info. I finally got a hold of the previous owner and he had the cheap conversion done by a shop. I was adding a can of 134a yesterday and saw the r-12 sticker and got worried but now knowing it has been converted I feel much better now and much colder.

I'd check for any leaks in the system, but that's just me.

 

[runningred92]

yeah I need to check for sure. the previous owner said he had to have it recharged at the beginning of every summer. A small note he forgot to mention when I was buying it in Feb.

 

[mr cribb]

yeah I need to check for sure. the previous owner said he had to have it recharged at the beginning of every summer. A small note he forgot to mention when I was buying it in Feb.

LOL in Feb when you got it you were more concerned with the HEAT working right?

It's always nice to find those "little notes" after the fact....

 

[Jason94sport]

the previous owner said he had to have it recharged at the beginning of every summer.

That's what I'm saying about the conversion kits. The 134 leaks out of them unless all the stuff is swapped. Something about the size of the molecules on r12 compared to 134.

 

[Anime]

You can "convert" an R-12 system to R-134a by just evacuating the R-12 + oil out, refilling with R-134a + oil in the correct amount, and then popping on R-134a retrofit fittings.

But that only works on some systems that are in really good shape, and that have a compressor, condenser, and evaporator that do okay with R-134a.

Even so, it's better to replace the old hoses with new barrier ones, not just because they do better at preventing the smaller R-134a particles from getting out, but in replacing the hoses, you can replace the rubber o-rings with the green ones. The o-rings are the most common leak point, so if you just recharge a system, whether it's with R-12 or R-134a, you might wind up having it all leak out over time.

 

[mr cribb]

You can "convert" an R-12 system to R-134a by just evacuating the R-12 + oil out, refilling with R-134a + oil in the correct amount, and then popping on R-134a retrofit fittings.

But that only works on some systems that are in really good shape, and that have a compressor, condenser, and evaporator that do okay with R-134a.

Even so, it's better to replace the old hoses with new barrier ones, not just because they do better at preventing the smaller R-134a particles from getting out, but in replacing the hoses, you can replace the rubber o-rings with the green ones. The o-rings are the most common leak point, so if you just recharge a system, whether it's with R-12 or R-134a, you might wind up having it all leak out over time.

That makes sense.... and our trucks are on the verge of being 20yrs old anyway, so it can't hurt to replace these worn out/ damaged items.

 

[runningred92]

I have checked every possible visual from the top for leaks. I didn't see anything leaking after I put new R-134a with the die in it in. I charged it and drove around town for about 30 minutes stopping periodically checking for leaks while leaving the air on high the entire time. Other than about freezing to death I didn't find anything. Is there any thing else to do other than start replacing hoses and gaskets and o-rings till it stops all together. Most of the system seems to have been replaced except for the dryer/condenser. Could I possibly get them from a 94 at a pull a part for cheap or is it something that I should get new?

 

[Jason94sport]

If you swap things now you will have to vacuum everything out & start over. If it works now just leave it. When it goes out again then revisit it.

 

[Anime]

Just leave it for now.

The best thing to do in the meantime is probably to run the system, since that's what keeps the o-rings and seals lubed as it circulates the oil. Just run it until it no longer cools, then worry about replacing whatever needs it before a recharge.

 

[cogs]

i have the r134 in, but the system is already pressured. now, when it isn't cooling well, i tried to refill the r134, but the pressure is already as high as it'll get. how do i discharge it?