Stay with R12 or convert to R134a (2 Viewers)

[ddnuts]

Hey guys,

My compressor stopped working the other day and I've read that when the freon is low the compressor will stop working. I'm hoping that is the issue. What I want to do is figure out which is best between R12 & R134a. Not sure of the benefits of 134a.

Please help!

 

[sitesbyjoe]

Mine still uses the old stuff. Cost me $180 to fully recharge it as it was empty. But my compressor worked still.

 

[ddnuts]

Mine is still using R12. The AC shop here is telling me that it will be a minimum of $300-400 just to check it out. Ouch!

 

[Cruzerman]

Lat year, I bought a FZJ80 where the A/C didn't work. It used R12. I decided to convert to R134a. The advantages of R134a is that it is cheap, readily available, and environmentally friendly. I bought a manifold set and a few other specialty tools needed to recharge / convert. I figured that if I got it working, it was still cheaper than taking it in and I would have the tools for future use.

Well, it works like a champ! I live in western Oregon, so it doesn't typically get really hot, but the A/C blows very cold. I'm extremely pleased with the results.

 

[SteveH]

If your Cruiser has been very slowly losing refrigerant over the years, and now it has reached the point where the compressor won't run, I would consider adding R12 to see if that brings it back to life. One can should cause the system to start working again, if this is the case.

My truck had been parked and driven 1x/year for several years, and while the compressor cycled, the center vent temp was 66F. I added one can of R12, and the temp dropped to 44F - problem solved. Works great.

If you think or know that your A/C system has other troubles or needs other repair, I would consider converting it.

 

[db3]

First find someone with a gauge and verify you have at least 40# pressure in your system. If you do, you might have a electrical problem, either the low pressure switch, the amp, or a wiring issue. Years ago I had the connector fall off the low pressure switch. There is a great thread concerning troubleshooting the amp. If the pressure is low, recharging is an option, but it's getting very pricy, so converting to 134 might be a better option, especially if you plan on keeping the cruiser for the long term.

 

[doug720]

If you need to replace the compressor, go to 134, but, you should use a 134 compressor.

Why? R134 gas has smaller molecules than R12, and 134 compressors have triple lip seals to help keep the gas from leaking. A R12 compressor will work, but the chance of a seal leak is high.

I converted my 60/2f from R12 to 134 with the stock compressor. It cooled great, but the seals started to leak within a few months, requiring recharges. When I did my diesel swap, I used a 134 compressor and my AC has worked great for many years now.

Just a suggestion.

 

[1972FJ55]

Assuming that it's still an R12 system and it's just low, buy a couple cans of R12 on Craigslist and find a friend with some gauges and add enough to clear the sight glass. If the system is empty, you can either keep it R12 or retrofit to R134a. In either case, find and fix the leak.

 

[lechnito]

Hey @ddnuts. I took my rig into Beaverton Radiator two weeks ago to have my A/C checked out and had a good experience. They added R12, replaced the valve stems, and added some dye to help detect any leaks. Total ended up being $368, a little over half of which was the the cost of the R12.

 

[SteveH]

If they got you going again for that amount, that's not too bad. At least they were willing to work with you, rather than just chucking it all and starting over with new parts.

 

[Cruzerman]

If you need to replace the compressor, go to 134, but, you should use a 134 compressor.

Why? R134 gas has smaller molecules than R12, and 134 compressors have triple lip seals to help keep the gas from leaking. A R12 compressor will work, but the chance of a seal leak is high.

I converted my 60/2f from R12 to 134 with the stock compressor. It cooled great, but the seals started to leak within a few months, requiring recharges. When I did my diesel swap, I used a 134 compressor and my AC has worked great for many years now.

Just a suggestion.

I didn't swap out the compressor. I replaced all the O-rings and also the seals on the compressor. It's been a year, no leaks. Again, this was on my 80 series, but I don't think there really is any difference. YMMV.

 

[Zack1978]

Are all new (or rebuilt) compressors available today 134 spec?

 

[1972FJ55]

If you buy a Denso compressor, it comes with ND6 oil (mineral oil) for R12. You can drain that oil and replace it with ND8 (PAG 46) and it will work great with R134a. The seals and O-rings inside the compressor are compatible with both refrigerants. Assuming you have an FJ60, you'll want Denso #471-0204 available on Amazon.

 

[ddnuts]

Perfect. Thank you guys for all of the information. I'm going to get this fixed up as quickly as possible as we are taking a trip soon and it will be HOT! If y'all think of anything else, please don't hesitate to share.

 

[Honger]

This is a timely thread as I have some AC questions...

I'm using an Old Air Hurricane 2000 in my FJ40 (thread here). It's meant for R134A based on the expansion valve. I have the motor mount with integral AC compressor mount for an FJ60 with the 2F. I know that Denso #471-0204 is the compressor that fits the bracket but it is listed as an R12 compressor.

1. If I replace the Denso's oil I should be good to go?
2. Given that the rest of the system will have never had the mineral oil or R12 run through it my o-rings should be good to go, right?
3. Would a 2F condensor designed for R12 work just as well with R134a?

Any thoughts?

 

[Cruzerman]

Again, I can only speak of what I did, but that was based on what many people told me when you convert to R134a. Clean out the entire system since the new PAG oil is not compatible with the old oil. I used cleaner that is designed for this. Replace all O-rings in the entire system. Replace the dryer. Replace the seals on your compressor. Replace the expansion valve. This is a pain, but not only most likely needed, it also gives you the chance to clean off the evaporator, which is most likely very dirty. Then add the PAG oil and put a vacuum on the system to check for leaks. If that checks out, charge the system. Good luck.

 

[1972FJ55]

This is a timely thread as I have some AC questions...

I'm using an Old Air Hurricane 2000 in my FJ40 (thread here). It's meant for R134A based on the expansion valve. I have the motor mount with integral AC compressor mount for an FJ60 with the 2F. I know that Denso #471-0204 is the compressor that fits the bracket but it is listed as an R12 compressor.

1. If I replace the Denso's oil I should be good to go?
2. Given that the rest of the system will have never had the mineral oil or R12 run through it my o-rings should be good to go, right?
3. Would a 2F condensor designed for R12 work just as well with R134a?

Any thoughts?

1. yes
2. yes
3. I'd replace it with a newer design parallel flow condenser. They're more efficient and work great. Something like this, depending on what fits in the available space.

 

[White Stripe]

This is a timely thread as I have some AC questions...

I'm using an Old Air Hurricane 2000 in my FJ40 (thread here). It's meant for R134A based on the expansion valve. I have the motor mount with integral AC compressor mount for an FJ60 with the 2F. I know that Denso #471-0204 is the compressor that fits the bracket but it is listed as an R12 compressor.

1. If I replace the Denso's oil I should be good to go?
2. Given that the rest of the system will have never had the mineral oil or R12 run through it my o-rings should be good to go, right?
3. Would a 2F condensor designed for R12 work just as well with R134a?

Any thoughts?

I have done quite a few r134 conversions. With your 40 install new orings. Napa sells AC oring kits that have miscellaneous metric orings for like 5 bucks. If the compressor has a manifold on it for input and output, take the manifold off and replace oring gaskets with r134 compatible gaskets. Dump the compressor out measuring how much comes out and fill with r134 oil. Get a r134 dryer and fill that with the specified amount plus another ounce because some will settle in the condenser and evaporator. Remove the Schrader valve cores of the r12 ports and install adapters. Have it professionally vacuumed and charged. Don't use r12 especially if u have a leak, it is ridiculously bad for the ozone. Google it if u want to see just how bad. R134 is just s greenhouse gas and not too bad

 

[cederholm]

Cruzerman, can you point us to a step by step of your process? Mine blows cool air - far from cold! I'm assuming it's R12 and I'd love to convert it.

Thanks,
Carl

Lat year, I bought a FZJ80 where the A/C didn't work. It used R12. I decided to convert to R134a. The advantages of R134a is that it is cheap, readily available, and environmentally friendly. I bought a manifold set and a few other specialty tools needed to recharge / convert. I figured that if I got it working, it was still cheaper than taking it in and I would have the tools for future use.

Well, it works like a champ! I live in western Oregon, so it doesn't typically get really hot, but the A/C blows very cold. I'm extremely pleased with the results.

 

[red66toy]

1. yes
2. yes
3. I'd replace it with a newer design parallel flow condenser. They're more efficient and work great. Something like this, depending on what fits in the available space.

Those parallel flow condensers look like a good upgrade. Apparently they are 25-30% more efficient. That might make up the difference in vent temperatures that people report for R12 and R134a systems... I wonder how hard it would be to fit one.