Air conditioner recharging.

[andrewespo]

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

[andrewespo]

Does anyone know how to do it?

[351wStang]

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.

[andrewespo]

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

[351wStang]

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.

[xs29l]

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!

[StangNut86]

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.

[351wStang]

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.

[andrewespo]

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

[xs29l]

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!

[InUrHead]

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?

[malcolm brumley]

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.

[xs29l]

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!

[xs29l]

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.

[andrewespo]

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