i need help with my A/C

[dark240kid]

Ok so i just picked up a bone stock s13. Im in Florida and it gets really humid and Hot so air conditioning is a must! anyways my A/c system hasn't been converted to the R134a system it still has the R12 system. i went to autozone and they told me i can get a kit to convert it over,,i just switch the high and the low knob does anyone have instructions on how to do this conversion step by step or pics? i also heard i have to take the compressor out and flush all the fluid out or something like that??

[JayArr]

R134 uses different fittings for the high and low side, sometimes places like Autozone sell these as a "retrofit kit". If this is the case then it's a small start to what you have to do to change over, you need to have it evacuated of all the R12, then change the oil by flushing the system clean and installing new oil, then you need to pull a 30 pound vaccuum to remove all of the moisture, at 30 lbs of pressure water boils at about 50 degrees and any moisture will evaporate and be evacuated. Then you need to remove the vaccuum pump and drive it for a few days, if after a few days it still has all 30 lbs of vaccuum then there is no leak and you can add 134 but if after a few days the vaccuum is gone then you need to find out where the leak is and fix it. There is no sense in adding 134 if it won't hold a vaccuum since it'll all just leak out on you.

It's fairly complicated and you need to be very exact to get it right, on top of that it requires thousands of dollars in tools. (pump, guages, flushing equipment) etc. That's why it's usually best just to pay the $1000 that a shop wants to do it for you.

HTH

JayArr

[dark240kid]

$1000 damn thats a whole new motor lol i can see maybe like $300

[motoman399]

R134 uses different fittings for the high and low side, sometimes places like Autozone sell these as a "retrofit kit". If this is the case then it's a small start to what you have to do to change over, you need to have it evacuated of all the R12, then change the oil by flushing the system clean and installing new oil, then you need to pull a 30 pound vaccuum to remove all of the moisture, at 30 lbs of pressure water boils at about 50 degrees and any moisture will evaporate and be evacuated. Then you need to remove the vaccuum pump and drive it for a few days, if after a few days it still has all 30 lbs of vaccuum then there is no leak and you can add 134 but if after a few days the vaccuum is gone then you need to find out where the leak is and fix it. There is no sense in adding 134 if it won't hold a vaccuum since it'll all just leak out on you.

It's fairly complicated and you need to be very exact to get it right, on top of that it requires thousands of dollars in tools. (pump, guages, flushing equipment) etc. That's why it's usually best just to pay the $1000 that a shop wants to do it for you.

HTH

JayArr

just curious, how do you know all this?

[numbnuts240]

you don't have to drive it around for a few days. you just introduce a dye into the system, run it, and look for the leak with a black light. if there is no leak found, the whole conversion could be done within a few hours. but you are correct in saying that the equipment costs a butt load of money.

[JayArr]

just curious, how do you know all this?

About five years ago I took all the night school courses and bought all of the gear, I figured at the time that over my lifetime I would be able to do a dozen cars between what I collect and various family members so I forked out the $$ and got set up. I think I spent about $3500 on pumps, guages and tools, another $500 on oils, refrigeramts, parts, dyes etc and a few hundred for the courses.

It certainly hasn't paid off for me yet, I've only done two cars, the 240 coupe will be the third. Somewhere around number four or five I'll break even. It's good to know and I'm glad I did it but I wouldn't advise it unless you think there will be a dozen cars in your future that will need service.

JayArr

[JayArr]

you don't have to drive it around for a few days. you just introduce a dye into the system, run it, and look for the leak with a black light. if there is no leak found, the whole conversion could be done within a few hours.

That may or may not work, When I did my Cutlass it would hold the vaccuum sitting idle in the driveway so I added the refrigerant. It was all gone in a couple of days of driving, there must have been a cracked o ring somewhere that would leak when the car hit bumps. I got the tip about driving it around with a vaccuum from another tech and sure enough it would hold a vaccuum in the driveway for days but not out on the street under driving conditions. I tore it all apart and replaced all the o rings and that solved it.

Driving around with the vaccuum, as a test, is free, it won't cost you any refrigerant or oil but it does require the patience of waiting a few extra days to be sure.

[rb240mike]

It's pretty easy bro I just did it on my car because my R12 was low and I have a buncha cans of R12 and couldnt find my fitting for it. Luckily for me I do have an AC machine at my shop, but just drain all the r12, take apart the lines put r134 orings on in place of the r12 ones (I got lazy and didnt do it and left the r12 ones and it's still fine 6 months later). Put some pag oil in, bolt the retrofit r134 nipples on and fill it up.

[AZ89two4Tsx]

R134 uses different fittings for the high and low side, sometimes places like Autozone sell these as a "retrofit kit". If this is the case then it's a small start to what you have to do to change over, you need to have it evacuated of all the R12, then change the oil by flushing the system clean and installing new oil, then you need to pull a 30 pound vaccuum to remove all of the moisture, at 30 lbs of pressure water boils at about 50 degrees and any moisture will evaporate and be evacuated. Then you need to remove the vaccuum pump and drive it for a few days, if after a few days it still has all 30 lbs of vaccuum then there is no leak and you can add 134 but if after a few days the vaccuum is gone then you need to find out where the leak is and fix it. There is no sense in adding 134 if it won't hold a vaccuum since it'll all just leak out on you.

It's fairly complicated and you need to be very exact to get it right, on top of that it requires thousands of dollars in tools. (pump, guages, flushing equipment) etc. That's why it's usually best just to pay the $1000 that a shop wants to do it for you.

HTH

JayArr

This guy is right on the money. Listen to him.

As stated, make sure your system holds vacuum. Start from there or else you'll be wasting time and money.