cam355aro

I was completely out of refrigerant in my 84 and the gf wanted some cool air blowing. I had opened up the lines at one point and let all of the refrigerant out and I am sure had the lines full of air.

My main questions are:

1. Will having the lines full of air and not vacuuming them out hinder or harm the new refrigerant I add in later? What is the big deal of having the lines vacuumed out?

2. According the the hanes manual, the 84 holds 2.75 pounds of R12. I am obviously only going to add R134, so would this harm or hinder the system in any way. Also, does switching to R134 require less pressure than the R12 requires? (2.75 pounds to 2.25 pounds)

3. Does the refrigerant capacity reflect the net weight of the refrigerant bottle. IE: the bottle is 16 ounces, so I would need 2 3/4 bottles to fill up the hanes suggested 2.75 refrigerant capacity. Is this correct?

Thanks in advance, summer is coming!

c-4 lhozwalte

any air left in the ac will have moisture in it and when it comes in contact with the freon the byproduct of the reaction is goin to be hydrochloric acid.and that stuff doesnt react well with aluminium.high vacume boils water at a low temp and is the only way to insure a moisture free ac system.

and on another note youll need to convert your r-12 system to 134-a.i beleve that includes a new dryer and orfice tube,maybe a thing or two more.anyone else?

CorvetteMike2024

I would vacuum the lines. It removes the containaments from the system. Its very easy to do. I usually vacuum for about 10 minutes.

The risk of not vacuuming? All the dirt, water, and oil and what ever else is in there you will be pumping thru your system every time you use it. It will definatly shorten the life of your A/C unit.

You may be able to rent one somewhere.

Good Luck

Corvette Mike

exactmetal

a conversion kit is deff. needed to replace the r-12 to 134,,,i would also change out the accumulator,,,,,OR find an a/c guy where you live that does refrigeration see if he has any HOT -SHOT which is a direct replacement for r-12 and alot cheaper,,,also make sure you have a pressure test done befor adding any freon of any type. when i got my 87 it was completely out of freon,but the owner assured me that it was only empty because he had to remove a line to access something for a repair,,,i putt 150psi of nitrogen in and let it sit for 24 hrs. next day still 150psi so i put it on a vac for 45 mins and added r-12 . i have 30 lb jugs if any one is interested in buying some i have 3 avail. just pm me.

joe wilson

I changed my S10 over to R134 and it wasn't hard at all, but you do need to put a new drier on your car. It wouldn't hurt, while you have the ac apart to put new o-rings on the fittings. I was told the R-134 systems use different O-rings, they're not expensive. I would definitely drain all the old oil out of it because the R12 oil is not compatible with R134. Put new oil in it...I forget the name of the R134 compatible oil but any competent parts man can tell you what you need. Definitely vacuum it down for about 20 minutes or so or until it reaches 30 on the vac gauge, then vac for a while longer to be sure. You will not need as much R134 as you did R12, I think about 2/3 as much or so. I used a blue Ford orfice tube for additional cooling and it worked great. Before I did mine I read all about it at www.ackits.com They seemed to really know their business. Also after removing the old oil it is necessary to flush out all the old oil from the system. They sell the flush at Advance auto parts. I'm not trying to drum up business for anyone, that's just what I did when I changed mine over.

cam355aro

Ok so lets recap.

After some research and reading everyone's replys, I am going to have to get:

- a new drier
- a new orifice tube
- new fittings and O-rings
- flush out and change the oil in the compressor to the compatible R134a oil
- flush out all the lines
- vacuum out the lines
- add 2 pounds of R134a refrigerant to the system
- then enjoy the cool temps

tell me if I added or left out any steps that require attention.

I was thinking of doing this myself but I will need to buy everything and rent a vacuum. Would this be easier to just go to an air conditioner shop and get them to convert it? How much do air conditioner shops typically charge to convert these systems? Any input would be greatly appreciated.

exactmetal

u might want to just hire an a/c guy to PRESSURE TEST AND PULL A VAC and add (hot-shot)r-404 will also work,,,,,,this is a direct drop in for r-12,,,,,,no conversion necc. this is a heck of alot easier!!!!ASSUMING THERE ARE NO LEAKS.

c-4 lhozwalte

much easier.expensive.

cam355aro

I don't understand why the converter kits they sell only have the high and low pressure fittings and the refrigerant if you need to replace all of this other stuff. It seems like every year I have to add more refrigerant to the system because it continually leaks out. I have avoided going to a shop and getting the system dyed to find the leak because of the price. Won't the cost of getting the air conditioning shop to do all of this stuff cost a fortune? (150.00 ish)

SunCr

$150 might get you some new shraders at a qualified shop - is this your first car? The '84 was 30 large or more new - you can spend a 1/3 as much making it a semblance of it's former self - doing it yourself. But comparing the parts it might need to make the a/c cold again, let's say to an '86 Camry, it's still a bargain. The Camry's compressor is $434, new at NAPA. The Harrison R4 in your Vette - $319. Pros refer to the Walmart conversion packages as "Death Kits". Doing it wrong can kill what's left (and injure you if you really screwup). Shops - try the Poop Boys $29 a/c tune up special - will check it for a few bucks, maybe even free. A/c work isn't rocket science, but there is some science, so once you know what it needs, you can figure out how much you want to spend fixing it and repost for advice from those who have managed to work their way a through a rebuild or two. More conversion info is here: http://www.epa.gov/ozone/title6/609/...ers/index.html AND HERE: http://www.autoacforum.com/messagevi...&threadid=7927

c-4 lhozwalte

put the parts you need on it and pay some one to evacuate the system and charge it.its the cheapest way out most likely.

coupeguy2001

ok, now my way. i didn't evacuate the system, I took the car to a place that I had work done on my old compressor. The guy said honestly, he couldn't tell any difference if he evacuated all the oil out or just added. He said just put your new compressor on, and it will be ok. He said if anything is damaged, he would fix it for free. he told me to go to auto zone or checker, and buy one of those conversion kits, and just put in the oil (pag oil) and add 2 cans of freon, he preoiled the repaired compressor, and sent me on my way. In retrospect, he figured that with 8% humidity, it would be ok.
That was 4 years ago. I have added a couple cans of freon because the compressor as of late is showing signs of oil residue, indicating the seals are once again leaking after about 23,000 miles. It still blows 45 degree air, and cools fine. Sometimes it's 118 degrees outside, so I guess 23,000 miles in that kind of abuse is ok.

MikeC4

Once you have converted your hardware over to R134, these vids on evacuating and re-charging might be of some help:

c4sailor

I had mine converted a few years ago when my compressor shot craps. So, conversion, compressor, evaporator and accumulator plus R-134 and labor ran about 800 as I recall.

exactmetal

just have some one rechage it with r-12 or with hot shot,,,then you dont have to convert it,,,besides r-12 will always cool better than 134a its a cfc,,,were as 134a is an hfc if it damages the ozone its good for cooling,and if u can buy it at autozone or discount that should tell u something,,,,,134a is a staright out joke. keep it original keep it r-12 or else!!!!!!!

SunCr

Hot Shot is 50% R22 and not only do you need Barrier Hoses to keep it legal - you need them to keep it from leaking out. Why you would dump in something that's going to leak without the proper mods doesn't make a whole lot of sense to me (though mixing refrigerants can raise operating pressures to the point that the high limit trips or you blow a hole in the hood, so maybe having a small leak isn't so bad).

exactmetal

suncr i have had no problems at all with hot shot in my a/c system ,,,,,and besides you cant argue the fact that it is the suggested direct drop in for r-12.

MikeC4

You seem like a real expert on AC sytems, and I am sure that SUNCR knows nothing about them..

Please enlighten us on the wonders of Hot SHot and the ineffieincies of R134 ......

(jeez, I could have sworn that R12 was stocked in every auto parts stores 15 years ago....just like R134 is today)

twin540

Well I really don't know the properties of hot shot . I can tell you everything about r-22 and 410-a .134a is very similar to r-12 as far as pressure temperature relationship I think theres only 3-4 lbs of pressure off. Is is very important to pull a vacumm on the system air is the enemy to refrigerent, you'll be runing a high low pressure giving you false readings. I pull mine to 500 mincrons to get all the junk out. Bring it to texas and i'll do it for free..I do residential for a living but I have worked on chevy/ford/ chrysler/toyota back when I was in school. Ask and I shall answer..

SunCr

If you're doing Residential you should have a 608, know the rules, where to get info, etc - I know I wouldn't want you anywhere near mine - good luck.