Adding Freon To A/c System

[SC420]

As the title states, I am trying to add some R12 to my A/C system in my '92 but I cannot seem to find the low pressure switch to activate the compressor so that it draws in the freon. I found the drier underneath the headlight and usually the switch is close to it on most cars, but I still can't find it. Anyone know the trick to filling up the freon? Thanks in advance.

[jzz30]

first of all where did you get r12?

second: if you add r12 to a system with moisture in it the gas, moisture and oil will react and give you HCL or hydro cholric acid. r12 is dichloral difloural methane gas the chorine and hydrogen from the moisture in H2O will give you that reaction. acid through your 1000 dollar compressor does wonders!

third: if you forcefully activate the compressor without pressure failure will occur. and that is NOT the correct way to do it. the pressure switch is there to protect your expensive compressor not for you to bypass it and turn it on maunally.

fourth: if your "adding" freon to a system thats low enough that the compressor doesnt turn on then there is an obvious leak and all you are doing is wasting money as r12 goes for $600~$1000 for a 30lb bottle.

[SC420]

Got the R12 from my father-in-law. He had a couple bottles laying around that he never used. So how are you supposed to get the freon into the system without the compressor turning to draw in the new freon? The method that I described by manually kicking over the compressor is the way that most cars are refilled, and from what I understand, shops do the exact same thing. I do realize that the switch is there so that you don't run the compressor continuously, but you need to get it to kick over to draw in the freon. Right? That's how anyone that I have talked to who has ever refilled A/C systems has said how it is done and that's the way I've done it in the past. If Lexus cars are different, then they are different. I just want to know the "Lexus method" or what have you. This A/C hasn't ever been touched that I know of as I have had the complete history since it had 44K miles. I will probably take it to a shop to check for leaks and have them add the R12 as I don't really feel great about messing with this car. American cars are easy, but these are a different animal. Parts are too expensive to screw up and I don't want to dump a ton of money into it as because I'm forced into selling it. I still want it fixed right though. I love this car and I will regret getting rid of it, but I need a pickup really bad and I can't have both. :( Thanks for the advice.

[jzz30]

you cant just add freon to a system without pulling a vaccum first.

this is true for all cars.

anyway to answer your question. you are NEVER supposed to forcefully turn the compressor on by bypassing any sensors. when you fill the car with gas you have to have the a/c button on inside of the car. the can of freon being at a higher pressure then your a/c system or in your case a system at near atmospheric pressure, will flow from a high pressure to low pressure. kind of like filling your tire with air. once the pressure inside the system becomes high enough the pressure sensor in the system gives an ok to activate the clutch on the compressor thus turning your compressor.

[squirrel]

As the title states, I am trying to add some R12 to my A/C system in my '92 but I cannot seem to find the low pressure switch to activate the compressor so that it draws in the freon. I found the drier underneath the headlight and usually the switch is close to it on most cars, but I still can't find it. Anyone know the trick to filling up the freon? Thanks in advance.

Once you hook up the guages and start feeding in the freon it will automaticlly trip the switch and bring on the compressor when you get enough freon in the system:)

[Ratatat]

first of all where did you get r12?

R12 is not that hard to get. Maybe for someone isolated on an island. 1. Living in the middle of agricultural usa, it is still found, ie auctions, private sales. 2. it is the #2 item smuggled into the US from Mexico. Mexico got a 15 year extention for R12, after everyone starting phasing it out.

Of course drugs are #1.

And yes I have a few pounds of R12. Going rate is about $25 a lb.

[jzz30]

wow mexico got an extension!?

i still have probably closet to 25lbs left in my can. for such occasions because 134 sucks in r12 systems.

[gabep]

Be VERY careful of any freon from Mexico. You may be getting propane, not freon. That scam has been going on for years.

[Ratatat]

for r12 users, there is Freeze12, legal and goes for about $8 a can.

[AppleJack]

I'm in need of a few 1lb cans of R12. Anyone have any recommendations on where to get.

Note: I'm in Toronto and prefer not to bring it over from the US since I'm not sure if it would be ok to do that.

thanks

[Ratatat]

Freeze 12 comes in 1 lb cans

[sjc6765]

I just changed the compressor in my 93 sc300. I serviced it with r-134a after evacuating the system. I got the compressor on ebay for 169.00 no core charge. I now have 37 degree air coming from my vents. I have heard stories that r134a does not work as well as r12, but not the case for me. I am very happy with it.

[Ratatat]

my 92 is a 134 conversion and the air gets cold. Cant ask for more than that.