Air conditioner recharging.

My 88 gt needs the AC charged. My question is how do I take the old stuff out (vacuum it)?:confused:
Thx for help..

Does anyone know how to do it?

You have to have an evac machine. Or do it in a not so legal not so safe way and push the valve stem open.

Is their anyway to buy an evac machine? Would it be cost efficient, or just have someone do it at a shop?

You dont want to buy one. You also have to be licensed to own one. No it would not be cost efficient for an individual to buy one. I would just take it to a shop and save lots of time and money.The machine costs a few thousand dollars if I remember correctly.

If it's R12, you can just let the high pressure side fly and give it an R134a oil charge. I'm pretty sure the R12 and R134a oil can be mixed (says so on the R134a can). Just hold down the vavle on the hot side (high pressure) until it stops spewing. Then oil charge it and fill it. Should work great!

i was under the impression that you had to buy a kit to convert to r134... that and i have no idea how to charge an a/c system, or figure out high side/low side.

You do have to convert from an R12 system to an R134A system if you want R134A. You cannot just put the new stuff in an old system.

I have an adapter on for the new stuff R134A. So what your saying xs29l is that all I have to do is get new stuff and fill it up I don't understand what you mean by "Just hold down the vavle on the hot side (high pressure) until it stops spewing." Im new at the A/C maintenance. My usual A/C was opening the windows :icon16:

351WStang might be right about that. Here's what I'd do: Go to autozone or somewhere and pick up a can of R134a oil charge. Read on there and see if you can use it in an existing R12 system. I think if you get enough of the R12 oil and R12 refrigerant out then you can then add R134a oil and refrigerant to the system to charge it. Here's some things that might help. Start your car and turn the AC on high. Look for the two valves and feel the lines. The line that is cold is the low pressure line and the warm or hot line is high pressure. With the car running, you can hold in the high pressure valve and get rid of most of the refrigerant and oil. I'd be sure that you can recharge with R134a before you do this or you won't have any AC at all. Also, when you charge the system with oil, the can must be held upside down from the start. When you charge the system with refrigerant, the can must be held upright so you get air in the system and not liquid refrigerant. Remember to never attach anything to the high pressure line (hot side) or the can could explode. Also, make sure the AC is running when you attach anything to the low pressure side (cold side). Hope this helps!

I'm having a similar problem with my 90 GT. Recently had to replace the head gaskets, and not in a good mood, decided to discharge the a/c so I wouldn't have to worry about it. Let me tell ya a lesson learned, r12 tastes really bad. DO NOT discharge with a flat head screwdriver holding the valve stem down, hehe. question is, why can I not find a bottle of r134a that's adapter will fit my low pressure side valve?

You had better take it to a licensed shop. There is a stiff federal fine if you are caught venting R-12 to the atmosphere. They will have to convert it to R-134. Federal regulations require all vehicles after 1994 to have R-134.

Yup, Malcolm is right. There is a fine for releasing any refrigerant into the atmosphere. I usually look around for an EPA guy, but have never seen any. If it's within your price range, I'd definately take it to be done right, but I think it's a little pricey. Let us know how it turns out!

Well, I just found the R134a retrofit kit that I bought a while back. It says that you need to completely empty the system of R12 before adding the R134a oil charge. It says that if there is any remaining R12 oil in the system that the R134a oil will mix with it perfectly. You will need one can of oil charge (8½ oz.) for a mustang. My kit came with one can of oil and one can of refrigerant. The kit that I have has adapters that will fit any system (even pre 1976) I bought it at Wal-Mart for $30 something. I buy my R134a at SAMS club for $27 (12 cans) where it's cheapest. Not sure where you can get the retrofit kit now days, but I'm sure it's out there. By the way, I charged a (discharged) window mount AC with this kit a while back and it cooled down to 54 degrees. I guess all AC units are set up the same way.

Whats the going price when brought to a shop, to have the A/C charged?

I've never had a shop do ours, maybe someone else here has? It used to be really high, but I think the prices have fallen in recent years since 134a has been more widely available. You could call around and get quotes on exhausting your system, then you could put in the R134 yourself.

Dude I am ASE cert. in AC repair. Take it to a shop. The road you are on is the tollway to a complete AC system failure. you need the right equipment to do the job right.

You know what I think? I think this "Moderator" has a little higher esteem of himself than is due. He said this: "Do your homework.... a buick GS 455 stage 1 is what he is talking about. They are Hemi killers. A 440 is not exactly puny". So I did my HOMEWORK. Not only did a Hemi charger outrun the 455 Stage 1, but it did it by 1.2 seconds and with a higher gear ratio. Also, the 340 Duster (compare 340 to 455) was only one TENTH of a second behind the Stage 1 in the quarter mile. So really, I'd think twice before taking his advice. I have PROOF, just ask.... you probably won't.

You know what I think? I think this "Moderator" has a little higher esteem of himself than is due. He said this: "Do your homework.... a buick GS 455 stage 1 is what he is talking about. They are Hemi killers. A 440 is not exactly puny". So I did my HOMEWORK. Not only did a Hemi charger outrun the 455 Stage 1, but it did it by 1.2 seconds and with a higher gear ratio. Also, the 340 Duster (compare 340 to 455) was only one TENTH of a second behind the Stage 1 in the quarter mile. So really, I'd think twice before taking his advice. I have PROOF, just ask.... you probably won't.

Do you enjoy starting trouble?

Hypsi just so happens to be perfectly right. Can you even decribe what an A/C system does and in what order xs29l?

Yeah, it's real simple. Certain types of gas gain or lose heat according to pressure changes. The compressor in the AC system pressurizes the refrigerant causing it to heat up. The purpose of pressurizing the refrigerant is to reduce the pressure on the other side of the line. When pressure is reduced, the gas cools. As for trouble, I don't like when people think they are great just because they have a "certification" or a "degree". What I do like is when people try to give practical and reasonable help to those who are not as versed, or who might not be able to afford "the best". Of course you need the right tools for the job, aka a retrofit kit from AutoZone or Wal-Mart. Since you guys don't think it's possible to convert R12 to R134a, prove me wrong and I'll admit it.

WTF???? The post that I said that in is over 3 months old, and it did happen the GS were and are still known as the HEMI killers. It happens get over it

Well, I just found the R134a retrofit kit that I bought a while back. It says that you need to completely empty the system of R12 before adding the R134a oil charge. It says that if there is any remaining R12 oil in the system that the R134a oil will mix with it perfectly. You will need one can of oil charge (8½ oz.) for a mustang. My kit came with one can of oil and one can of refrigerant. The kit that I have has adapters that will fit any system (even pre 1976) I bought it at Wal-Mart for $30 something. I buy my R134a at SAMS club for $27 (12 cans) where it's cheapest. Not sure where you can get the retrofit kit now days, but I'm sure it's out there. By the way, I charged a (discharged) window mount AC with this kit a while back and it cooled down to 54 degrees. I guess all AC units are set up the same way.

OK lets break this down and get this back on topic... The type of oil that is used in todays R-134a is called PAG oil, Which is not compatible with the R-12 oil (Can't rember what they called it, they did not even teach R-12 crap in calss.) if you are charging a R-134a system, you need to use PAG. However, if you know anything about AC systems or have taken classes, you would know that when you do a retro-fit (converting from R-12 to R-134a) you use a different kind of oil called ESTER. ESTER, is compatible with the oil used in R-12 systems and also is safe to use with R-134a. 81/2 oz oil charge???? :lol2: if you drain the whole system. Most of the oil in you AC system is kept in the compressor. When you pull a vacume on a system, the most oil you will EVER pull out of a system is 3 oz max. (Unless you have an AC system that is already overcharged with oil...) So do the math you pull a vacume on a system and you take out 3oz max (I have only ever pulled about a 1 oz usually.) and your AC system calls for 9 oz total (varys depending on the system) but, you put in a 8.5 oz oil charge... 9 oz-3oz+8.5oz= a grand total of 14.5 oz of oil in your 9 oz system... Also did you know that if your system uses 3 lbs of R-12 that you will use less R-134a? If you retro fit a R-12 system and put the same ammount of R-134a back into it, you will be overcharged and risk damage to your AC system (for example, your compressor will explode.) Oh another good point, on a 12 oz "suicide" can you will usually only get about 8-9 oz of charge out of it. In class we hooked one up to a recovery machine and the most it could suck out is 9 oz. Also, how do you plan to get all the moisture of of the system that you created when you just pushed the shrader valve and let all of that freon go into the atmosphere? The sudden change in tempature in your AC system from the expansion of the R-12 you let out will hurt your AC system. Moisture is an AC systems worst enemy. Also how do you plan to remove the oil/R-12 residue off the lines and such without a vacume pump? Just because you pushed that little shrader valve in and watch a big cloud of oil/R-12 come out does not mean it is all out. You vacume a system out to boil out all the crap in a system. You need to pull a vacume on a system.

All of that and you could only get your AC system down to 56 degrees... Using the proper equipment and processes, you can esely get a retrofitted car to blow 45 degree air out of the ducts on a 100* day.

If you want my ASE certification numbers to look up the authenticity of it, I would be more than happy to give them to you.

Also, you can just say "Oh just let the old R-12 out of the system" but, do you accually have ANY clue what that shit does when it gets up into the atmophere??

Why didn't you just say this before? I don't doubt that you are certified, never did. You can call them Hemi killers, but that doesn't make them Hemi killers. They are fast cars, and might have more overall potential, but from the factory they are slightly behind the Hemi cars. I got a window mount AC down to 56, the car got to 43 (ironically close to the 45 that you just stated). All that talk means nothing to me. I have converted R12 to R134a by myself and it's running at 43 degrees. Yeah, I put about 8oz of oil in the system just like the instructions said. That's proof enough for me.

depending on your area R-12 can still be gotten but for about $40-$65 a pound, I nolonger have any vehicles that take R-12 but ive got close to 100lbs of the stuff, and it seems that its much easier and much cheaper to switch over to 134a just make sure they evac your sys a little extra and get all liqued out it will make 134a much better at cooling. oops and a retro in some areas go between $80-$150 for 134a