Vintage Mustang Forums banner

1 - 13 of 13 Posts

·
Registered
Joined
·
4,800 Posts
Discussion Starter #1
I am considering changing over cause I think I've got a leak and freon is damned expensive. I have a charging kit but I need to know what is needed to change over and what are some of the pitfalls to watch out for.

What seems relatively straightforward usually kicks me in the butt.

J. Boggs
 

·
Registered
Joined
·
20,889 Posts
As long as R12 is available, I'd stick with it. Repair the leak and re-fill. The 134a isn't as effecient and opperates at higher pressures. If your old hoses aren't up to snuff, you'll have more problems. The oils are different between the systems and thoroughly needs to be flushed from the system by taking everything apart.

By saying money on cheaper refrigerant, you'll more than make it up in modifing the system correctly for 134a.

Tom
You can do anything you want to......ONCE!
aka "my 66 coupe"
 

·
Registered
Joined
·
529 Posts
I too recommend you fix the leak and reload R-12. If you decide to convert to R-134a, you will still need to fix the leak, flush the system, replace the oil, receiver/dryer, and likely the condenser. R-134a opeartes at higher discharge pressures and temperatures so you system needs to be in very good shape if you expect any sort of effeciency.

Vintage Burgundy 1966 Mustang GT Fastback (Midlife's younger brother)
MCA member #46447
 
G

·
Guest
Joined
·
0 Posts
I have done it to both a factory air 68 and a hang down unit. I did a lot of research and listened to a lot of different opinions on flushing the system and changing hoses, etc.. In the end, I did not flush the old oil out or change the hoses (some people claim the old oil will just pool and not recirculate with the 134a, which is ok). I did add new 134a compatible oil and 134a refridgerant. As long as your system components are good, the stuff works great. I used the hang down unit with 134a last year in the 100+ Texas heat in traffic and it cooled fine. One of the people who gave me the advice to just do it without the flush and hose change happened to be my father who was an auto mechanic for 25+ years, so I took his advice. The other advice I took is to put a new dryer on the system while doing this work. Anyway, that's my experience, good luck.

Jeff Crumpley
Austin, Texas
68 302 j-code coupe
99 5.0 Eddie Bauer Explorer
 

·
Registered
Joined
·
405 Posts
I'd like to hear from more people who have actually done it. I too face this same challenge, as they removed the compressor with my recent engine replacement.

http://66cherry.stangnet.com
Member NTMC
http://albums.photopoint.com/j/View?u=1611748&a=12299913&p=45161411&Sequence=0&res=high.jpg[/url]
 

·
Registered
Joined
·
7,671 Posts
I have done the R-12 to the R-134A conversion not on a Mustang but on a Nissan..... I took each piece off (condensor, hoses, compressor) and washed all the petroleum based refrigerant oil out with mineral spirits, bolted everything back in with new "O" rings, replaced the filter/dryer, added the correct amount of ester refrigerant oil, evacuated and charged with R-134A. Bought the adapter fittings at Wal-Mart.

With R-134A in the system, the register air is 43 degrees on an 80 degree day.... Can't do much better than that... IMHO

Required tools for operating a Vintage Mustang:
1. Duct Tape
2. J.B. Weld
3. B.F.H. (Big Fat Hammer)
4. VINTAGE MUSTANG FORUMS II
View Album Here: http://albums.photopoint.com/j/AlbumIndex?u=1616948&a=12352157
 

·
Registered
Joined
·
1,793 Posts
i went to Walmart last spring and got the kit ,fittings,oil, 2 cans of 134, and put it in my 91 explorer,abt 34 bucks total and it got me thru another summer, and it worked fine.
mine had a very slow leak before hand,which i knew about, so i got an extra can for later, didnt need to add any all summer....i figure ill add another can soon, if it ever warms up again this year.

[color:red]1965 A code fastback c4 with factory air ,power steering and front disc, 10/64 build ,a pre GT...GT</font color=red>
[color:green]My web site is [color:purple]here</font color=purple>
http://www.valkyrie.net/~wayne50f1
 

·
Registered
Joined
·
660 Posts
First of all refrigerant oil is not petroleum based. Its a parafin (wax) free oil that has to have a pour point at -40 degrees for R-12 systems. Changing out the oil is not required in the swap out kits. You don't have to change hoses,filters,driers,or O rings. The only thing that has to be changed is the schrader valve (acess valve) that allows the R-134 to be installed. The only reason for the "change" of this valve is to ensure that only R-134 will be put into the old R-12 system. Furthermore,no car,not a one has ever had,or will ever have an AC system that will remain leak free for any length of time. With R-12 going for $1500.00 for a 30 lb cylinder switching to R 134A is the way to go. The worries about higher pressures are over blown. The temperature-pressure relationship delta is not that much. The kit is just like the old back yard R-12 "hand grenade" kits. Follow the directions and it will work just fine. Hope this helps.....
 
G

·
Guest
Joined
·
0 Posts
I have converted an 89 Bronco and an 89 Mustang GT. You can use your old hoses if they are in good shape. The old oil in the pores of the hose will keep the smaller 134a molecules from passing through. If you have new hoses made you must use the "barrier" type of hose. All O-rings should be replaced with the green or blue type. The black type are not compatible with 134a but old ones which are not disturbed may be OK. The receiver dryer (if it was exposed to R-12) must be changed. New receiver driers are compatible with both types of freon. The oil MUST be changed. You must use PAG or ester oil since the old type oil is not emmissive in 134a. Flushing is a plus but just pouring out the oil from the compressor will work too. Results from conversions are mixed. Some work as good or better while others do not get much colder than 60 degrees or so. My Bronco worked great, but the Mustang was adequate rather than satisfactory. The big difference in the systems is that 134a requires a bigger condenser than 12 to work well. Given the cost of 12 it only makes sense to convert and hope for the best. The only other peculiarities of 134a is that less freon is required (about 15-20 % less) and the milky color precludes using the sight glass to determine when the system is full. Go for it !!

Mustang Lovers ---- A Box-O-Choclates !!!
 
G

·
Guest
Joined
·
0 Posts
I paid to have mine converted because the compressor went south but was still under warranty and they also put in a new dryer and hoses. The cooling is adequate but could be better. We determined that the evaporator from the old factory system should be replaced with one like California Mustang sells but I didn't want to pay that much ($229) at the time.
Tom

1967 Coupe
Auto
http://www.fortunecity.com/marina/kingfisher/1369/index.htm
http://albums.photopoint.com/j/View?u=1581047&a=12070911&p=43670918&Sequence=1&res=high.jpg
 
G

·
Guest
Joined
·
0 Posts
Go with Freeze 12, it's a blend, mixes with R-12 with no changes and cools fine. About 12 bucks a can. Or
do a extremly good deed for somebody and get surprised by finding a 30 pound can of 12 on your porch
with a thankyou note.

66 Coupe, 289/2v, C4, CA Red
 

·
Registered
Joined
·
4,800 Posts
Discussion Starter #13
Ironically, my ever resourceful father in law bought a couple of dozen cans of R12 as they were taking them off the shelves about 10-12 years or more ago. Said he paid 25cents each for them and he'll let me have them if I can figure out a way to get them home. He lives in Seattle, me in Atlanta. Airlines won't let them fly--even in a suitcase.

Anybody driving from Seattle to Atlanta anytime soon?

J. Boggs
 
1 - 13 of 13 Posts
Top