What's the best type of refrigerant to use?

[haydenm315]

I've got the environmentally frowned upon R 12 in my system. There isn't enough to turn on the compressor. What route should I take?
1 - Get some R12 from one of my sources and top it off.
2 - get the pressure up with the remaining R 12 and a bottle of freeze 12.
3 - Drain the system of R 12, and refill with R 134A

To me, 1 seems the cheapest, followed by 2, and lastly 3. What exactly is this Freeze 12 stuff I see at the store?

 

[philallemang]

R-12 cools the best.....Stick with it. If you go R-134a you have to pump the system down and clean it out, a long and mess job. Sometimes changing from R-12 to R-134 creates a "sluge" and you have to get new parts cause its just cant be cleaned out.

 

[AutoSHO]

Well, I have a bit of knowledge in this area. First off, R-12 is a FAR superior refrigerant to R-134a. It has close to double the heat exchange capability. What this means, is that systems designed for R-134a have a bigger compressor and condensor. Thus, a system designed for R-12 will never be efficient with R-134a. It is just a poorer refrigerant.

What I'm saying is, find the leak in the system, have it fixed, and refilled with R-12.

 

[mike]

r134a isnt bad for the environment though, which is why its used, even though it sucks. fyi

 

[NWGRN94MTX]

AutoSHO:
Well, I have a bit of knowledge in this area. First off, R-12 is a FAR superior refrigerant to R-134a. It has close to double the heat exchange capability. What this means, is that systems designed for R-134a have a bigger compressor and condensor. Thus, a system designed for R-12 will never be efficient with R-134a. It is just a poorer refrigerant.

What I'm saying is, find the leak in the system, have it fixed, and refilled with R-12.

I agree, This is what I would do.

 

[Xs SHO 1]

R12 is expensive, no?

 

[Hubes]

r 12 is actually illegal and really not produced anymore, thus making it expensive. i ahve also been told r 12 is much cooler than r 134

 

[rendyx]

My dad is an HVAC worker, and finds R-12 much better than R-134. You might look for something called "Hotshot," which I believe is a R12 replacement, and almost as good.

Why is R12 better? Because when we put a thermometer on the heat vents in the van (R12), and cranked the A/C, we reached about 30 degrees (farenheit eek! ).

 

[haydenm315]

AutoSHO:
Well, I have a bit of knowledge in this area. First off, R-12 is a FAR superior refrigerant to R-134a. It has close to double the heat exchange capability. What this means, is that systems designed for R-134a have a bigger compressor and condensor. Thus, a system designed for R-12 will never be efficient with R-134a. It is just a poorer refrigerant.

What I'm saying is, find the leak in the system, have it fixed, and refilled with R-12.

I think it's gonna be hard to find R12. I did talk to one of my friend's dads who's a mechanic yesterday. He said that he may be able to get R12 for $20 a bottle.

I looked at the system and didn't see any telltale signs of leakage around the seals. It's still got pressure but apparantly not enough to start the compressor. I troubleshooted by jumpering the plug that goes to the A/C cyclic switch for a moment to see if the compressor goes on, which it did. I've replaced the cyclic switch and it still doesn't turn on. I need a piece to complete my dad's manifold gauges. Apparantly one of the knobs is missing. I tested pressure in the cold with the car off and it was around 20lbs in 20 degree temperatures on both the high and low side. Someone later told me that I should take the measurements with the car running but I never did get to do that. Any suggestions? What the **** is freeze 12?

 

[haydenm315]

NWGRN94MTX:

AutoSHO:
Well, I have a bit of knowledge in this area. First off, R-12 is a FAR superior refrigerant to R-134a. It has close to double the heat exchange capability. What this means, is that systems designed for R-134a have a bigger compressor and condensor. Thus, a system designed for R-12 will never be efficient with R-134a. It is just a poorer refrigerant.

What I'm saying is, find the leak in the system, have it fixed, and refilled with R-12.

I agree, This is what I would do.

I think a seal dried up some and caused a loss of pressure due to not being run for a long time. Is it possible for the seal to repair itself after being lubricated again from running the system once it becomes fully charged?

 

[Xs SHO 1]

Hubes:
r 12 is actually illegal and really not produced anymore, thus making it expensive. i ahve also been told r 12 is much cooler than r 134

its illegal for environmetal issues, it eats up the ozone pretty good. also, i believe if some of u will be doing ur own refrigerant pump down/charging, u need to be certified to handle those tasks. EPA is really **** about that. but i dont think the EPA will know who is doing what and when. its always a good idea to be safe especially when if it affects the air we breathe....

 

[Xs SHO 1]

on the same note, did our shos come with the R12 refrigerant?

 

[luigisho]

The early SHO's came with R-12. It is better but it's also getting phased out. It is illegal to vent this stuff directly to the atmosphere. Shops are required to vacuum it out and capture it. $20 bottle isn't bad. Take it to a shop that even has it available, and it's around $70-75 lb. With how much leaks out to locate system leaks over time r-134 will pay off. The question is with cars this old is there enough time to recoup the cost?

 

[SHOZ123]

'93 is the year the r134 was first used. There is a refrigerant that can be added to a r12 system and will work. Don't know the name or nomenclature, might be the hotshot mentioned above. I will ask a guy tonight at work who has used it.

 

[jelloslug]

There is no real drop in replacement for R-12. Freeze 12 and other are blends of various refridgerant (R-22, R-134a) and butane eek! . R-143a and R-22 are not compatable with the dryer or the oil that is in an R-12 system. To find your leak you should eather use the dye stuff (never tried it) or an electronic sniffer (my dad has one of those and they work great). If your system has been discharged for some time you should replace the dryer and all the o-rings first, then recharge. If you go with R-134a you might need a different orifice tube. I have changed over many car of many different ventages and have never needed to change the oriface tube yet. R-12 does cool better but I have found that R-134a will do the job and is much cheaper if your system ever gets another leak. I am planing to change my '90 over to 134a soon.

 

[Rob94]

FWIW, my 94 uses R-134a and I really don't notice much of a difference compared to cars I've owned in the past with R-12. Oh yeah, moved to maintenance, engine and driveline.

 

[AutoSHO]

Rob94:
FWIW, my 94 uses R-134a and I really don't notice much of a difference compared to cars I've owned in the past with R-12.

Thats because the system was designed for use with R134a. The retrofit kits never cool as well as a system designed for use with either R12 or R134a.

 

[luigisho]

That is usually because the compressors are different. For r-134a to cool as well as r-12 it needs to be under greater pressure than r-12. Hence the original r-12 compressor will not cool as well with retrofit kits.

 

[Xs SHO 1]

how much will it cost to get my '93 converted to the 134a?

 

[jelloslug]

xssho1:
how much will it cost to get my '93 converted to the 134a?

If you do it yourself (and have the tools) it's the price of the changeover kit (around $40) A new dryer (you MUST change it, $40 I think), and any O-rings, hoses,or any other parts that are bad (which there will be, thats why its not charged right now). Add several hundred to that to have someone do it for you.