Alright, I worked all summer at a shop doing tires, oil, ect. One of the things I did during orientation was get MACS certified to handle R-12. Now, in connecticut where I live, they dont sell it to Anyone.

Now I am at college in new hampshire, and I went to pepboys today to see if they sold R-12, and once they looked at my certification, they asked if I wanted a 30lb canister or some 12oz cans. I was like cool, but I dont need any today.

So heres the problem. I have never worked on any AC before at all. I know the techs at work used the machine and a set of hi-lo guages, but I would have no idea what to do with them. I had two different mechanics look at it, and they both took off a cap on one of the fittings, and pressed their finger and a huge cloud of R-12 came out. They both said I had about half of the origional charge. Also if the A/C is on at idle, the compressor cycles on and off very rapidly (every 2-3 seconds) and I havnt felt the vents get cold.

So Im really tight on money now, but winters coming and I want to be able to use the defroster without the compressor going crazy. What would my best option be for real cheap? Assuming I have no major leaks (half the origional charge after 17 years aint too bad i dont think).

Also, which fitting is the high side and which one is the low side? I am guessing that the low side is the one pointing straight up?

 

Nobody can help?? At least tell me which one is the low side so I dont explode the can!

 

The low pressure port is the one on the accumulater (the big canister that comes out of the airbox). If you are only toping off the system I would only connect the low side of the guages and charge it. the way you describe it its probably only needs about a half can of freon. that being said you can probably convert to 134 cheaper than that one can of r12 going to cost ya.

 

Yeah but I have heard nothing but bad luck with 134 conversions. I should have asked them how much a can of R-12 costs, really expensive? How about Freeze-12? It says it is totally compatible even as a top off to R-12.

 

On that 17 year old system I would for now just top it off. If you convert it to 134A (which I have done with quite success on both my cars) I would replace the compressor, orfice tube and accumulator and flush the evaporator, condenser and related lines. There are some issues with the conversion but you learn to deal with them. If you replace the lines and manifold off the compressor STAY AWAY from the POS parts from Ready Air sold through most bargain outlets, buy from the OEM. I fought leaks and Advance Auto Parts sorry warranty claims service on this one. The Ready Air hoses have sorry crimps at the hose ends. Don't cut yourself short on the compressor but a quality part again stay away from the bargain house. Go to NAPA they use the same rebuilder but their warranty is much better 3 years vs 3 months. Orfice tube and accumulators are pretty much generic but buy from whoever you get the compressor from to maintain their warranty.
Buy all new "O" rings and oil them with PAG oil and be careful with the fittings don't allow them to twist as you tighten them and don't over tighten them. Evacuate the system per specs and recharge with PAG oil and R134a you might even use some leak detector in the system for telltale leak detection. Good Luck.

Mike

 

Well, I would rather just have no A/C then convert to 134. Thats why I got a car with t-tops and power windows. I had A/C that blew ice cold in my 95 monte, but I hardly ever used that.

What I was really hoping is that I could find a cheap way to get it working again. I saw a thread about the guy that put a vacuum on the system and used Autofrost to refill, but I also read that Autofrost has issues with stock lines and seals, and people were saying that his was probably getting too cold and forming ice in the A/C system.

Then, I looked for info on Freeze-12 and couldnt find any solid info. Also, whatever I do I would like to keep my stock fittings if possible. Not have to convert to different fittings.

So, the Low side fitting is the one that sticks out of that big silver canister on the passenger rear of the engine bay? Not the one that is inline and points straight up?

 

Oh well I was trying to help then if you don't want the system pull it. Not trying to flame you but even with your cert. you obviously don't know much about AC systems so I'd just leave it to the pros.

 

No, I really dont know anything about A/C systems. The only thing they taught us in the course was a bunch of BS about the ozone hole, and how the PAG oil isnt compatible with mineral oil. They never taught us how to do A/C recharging, just how to keep the aptmosphere happy.

But I want to learn how to recharge my AC. I dont have any money really to pay someone else to it.

 

Trying to re-charge an R-12 system on the cheap is a very tough
row to how. All the new quick & easy equipment for R-134 uses
different style connectors, and the old R-12 style connectors are
virtually impossible to find. Service shopls will have the legacy
tools. (Being an hornary ole cuss, I fabbed up
a set of adapters to connect either style, into the manifold & gauge
set. Now if only I'd kept the vacuum pump I had years ago...)

Converting to R-134 is a painful short term task, but the best
long-term soln, in terms of servicability.

Good luck,
kk

 

Yeah that ozone thing was a load of crap. It all revolves around Dupont money and the European Union trying to control the US. If I'm stepping on toes sorry but on this board as well as others I've seen some guys promoting propane as a refrigerant, imagine running into one of those jackasses. Sorry but I've never seen or heard of a car blowing up in a frontal collision because of freon but propane come on. Lets just load our cars with a MK-82 bomb and see how long we can keep from killing ourselves. OK political rant off, I'm burning the soap box.

 

You'll need some gauges with R12 ends on them. The low side is the big valve pointing diagnolly. The high side is the small valve pointing up. Charge through the LOW side (BIG valve).

Checking your gauges with the current setup, you'll probably see the low side falling fast. Cycling off in the mid 20's psi and then back up to 45 psi or so when it turns on. As soon as it rises up, it'll drop fast (since you're low on charge). With a proper charged system, it'll come down to 30 psi and hover around there.

You probably need less R12 than you think. Mine was cycling on and off every 5 seconds or so. I had about 1.9 lbs of R12 in it if memory serves me correct. Original charge was 2.25 lbs on my system. Don't just blindly put in an entire lb of R12. You'll be overcharged if you do that and it won't cool (pressure will be too high)

Different weather will have different psi readings. The hotter it is outside the higher the psi will read. Phoenix might have 35-38 psi at idle, Seattle might have 28-30 psi at idle. (Numbers just approximations off my head).

I'm the guy with the Autofrost. I don't think it has issues with ice. If it did, the ice would cause it to cycle off. Ice is more of an issue with variable displacement compressors rather than cycling compressors. (Variable systems keep it at a constant 28 psi all the time.) I get a lot of sweat on the lines when I pop the hood on a cold day. No ice though. The guy that invented the stuff ran into ice problems (like huge blocks of it) on a variable system that was running his HP stuff. That stuff ran at 25°F duct temps. Mine is the regular Autofrost stuff (31°) and cycles every once in awhile. The off cycle melts any ice that would be on the evaporator.

Actually I'm in Houston TX at the moment. Driving around in stop and go traffic here in the afternoon with 94° and 60% humidity, it's staying around 40°. The compressor doesn't turn off.
Getting on to to a highway where traffic is flowing, it goes back into the 30's and may cycle once in awhile. Pretty rare though.

For ease of recharging and avoiding the hassle of converting, I'd say recharge it with R12. Just be conservative with it and monitor the charge with some pressure gauges.

 

As for propane. Nobody has an issue with propane powered vehicles, yet somehow propane A/C systems get a bad rap. How many (non-rigged) propane A/C explosions have you seen or even heard of? I'd be more worried about the 100 lbs of gasoline in the trunk than I would a pound of propane in the A/C lines.

 

134 conversion will save you money in the long run but do it right the first time have the system vacumed out then replace the fitting (don't forget to use the ESTER oil)
I got lucky and scored 2 cans of r12 for 30 bucks.... avrage price is 30 bucks a can (12 ounces) freeze 12 from what i hear aint worth a lick (never tried it my self tho) price for r12 is rising every year it seems so if you get your hands on some keep it quiet or you'll have peeps asking for it ALL the time i recommend getting 2 cans of r12 to test your system if it doesn't leak out get a 30lbs that'll hold you over for the rest of the car's life.

 

I've never seen one happy person with Freeze 12.