[Hawk397]

Some of the sites that I've been checking into seem to have differing opinions about what's best and if components are compatible. My question is for anyone who's done it is:
If I rebuild the system in my 71 project with a new condenser,electric fan, evap, rebuilt A6, stock expansion valve and a POA valve adjusted to 26, will I get decent performance out of 134a? I was looking through a Year One Catalog last night and noticed an expansion valve listing with the note "not for 134A". Other than the POA adjustment, what's needed thats "special"?

Mark

[Hawk397]

Some of the sites that I've been checking into seem to have differing opinions about what's best and if components are compatible. My question is for anyone who's done it is:
If I rebuild the system in my 71 project with a new condenser,electric fan, evap, rebuilt A6, stock expansion valve and a POA valve adjusted to 26, will I get decent performance out of 134a? I was looking through a Year One Catalog last night and noticed an expansion valve listing with the note "not for 134A". Other than the POA adjustment, what's needed thats "special"?

Mark

[78 GHOST]

Hi Mark, with 134 you need to ensure your rubber hoses are "barrier" type hoses and that ALL O-Rings are changed to a compatible material. In addition, you can use two types of oil: (if I recall correctly) Esther and PAG.

I think Esther will allow you to go back to R-12 if you choose to at a later date. I believe PAG restricts you to R134A or the equivalent.

I'm a little rusty on the A/C stuff as it's been a few months since my last completion.

I replaced everything and switched over to R-134A on my Trans Am. I've never been terribly happy with it, but it works OK and I'll live with it. It could certainly use an electric fan switched through a relay to the brake pedal.. anytime you're stopped the temps climb.

Later, I did another complete on my GMC pickup which I drive daily. Needless to say, I was not going to deal with "OK" in Houston weather. I installed R-12 in this vehicle and it'll put frost on Satan's marbles.

R-12 is available at a premium price. However, I feel that given the need to stick with stock components in my cars, that the one time investment is worthwhile. Once the system is tight, the refrigerant should last a lifetime.

My Frame-Off project will also receive R-12.

Good luck on your project. -Matt

[Squidward]

Don't forget to replace the drier.

[Hawk397]

Yep, dryer too! I've got a guy at work with a full 30lb bottle of R-12 that he'll sell for $300 (Damn!!!) but I guess that a great price today! I may just bite the bullet and go that way!

Mark

[78 GHOST]

Mark, ask around at your local NAPA stores or look online for R-12. I obtained my R-12 from a local supplier for around $35/Pound.

For me, the 30# bottle makes a lot of sense as I have 3 old cars and expect to keep them. Over time I would use the refrigerant. If you're doing only one car 30# is a bit of overkill.

[79GP6.6L]

It seems to me that the performance of 134a systems vary depending on the system. I did a 134a conversion on my 89 Formula, replaced all O-rings, dryer, pulled a vacuum on the system for a loonngggggg time, then charged it, and it works great! I've seen some vehicles with factory 134a that don't work as well. I've serviced many 134a systems; some would cool into the high 30 degree to low 40 degree range, some seem to offer only marginal cooling ability.

R-12 will provide excellent cooling, but is expensive and the supply is diminishing, so I don't consider it a practical option, unless you are using it to top off a working system. If you mess up somewhere, or have a leak in your system, well...that's a lot of money escaping off into the atmosphere. Just my .02

[MitchGM]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by 79GP6.6L:
If you mess up somewhere, or have a leak in your system, well...that's a lot of money escaping off into the atmosphere. Just my .02 <HR></BLOCKQUOTE>

Let's see.... .02 cents worth at about $35 a pound.... That's about a drop.

[burgundygto]

Try going to ackits.com forum and look under "conversion and retrofit questions". You will find my thread "use less oil with retrofit?" and another newer one "POA adj, r134a in. results and questions." These will be very informative. I have also recently foundsomething that will help that involves your ducts. GTO'S and firebirds have an "INSIDE" and "A/C" position on the controls. I always thought that "inside" meant recirculation of inside air and no outside air, but that's NOT true. "inside" provides a mix of inside and outside air by opening the vent door halfway.I found that you can remove the driver side kickpanel to expose the vent door actuator and change things for the better. Pull the orange stripe hose off and put it in the green stripe hose position. Plug off the green hose and the orange hose port on the actuator. This will give you full inside air with "INSIDE" and full outside air with A/C" position. My car cools a lot faster and my temp was lowered by about 2 degrees.

[Hawk397]

Thanks for the info, I'll checkout the latest threads.

Mark

[ddouble]

Mark,

If you've got the license buy the R12! I saw a 30# cylinder go for $900 last year. No one around here will touch it. If you need a license go here. Good luck, I'm running fifty/fifty with my conversions right now. Just feel lucky it's not a Ford, They seem to have a higher fail rate on conversions.

Dan

[carzan]

No one has mentioned DURA COOL 12a.
In my opinion this is the only choice. Not only is it enviromentally friendly but it is supperior to both r12 & 134a in cooling effiency. Add to that the fact that it is a direct drop in replacement for either (no special components or changing oil, hoses etc.). Simply evacuate system and charge.

I'm using the 12a in two of my vehicles, and as my other vehicles need servicing they will be switched also.

a satisfied user
Edward

here a website with more info:
http://www.duracoolusa.com/

[wheelspin]

Mark,

I have restored the factory air systems on both my 68 GP and my 72 Firebird. I purchased the A-6 reman compressors from Autozone for under $100 ea., including a one year warranty; the POA changeover kits ($97ea.), driers ($30ea.), expansion valves ($24ea.) o-rings, and crimp sleeves from Mark's Air Inc, 813-988-1671, email: gordon@marksair.com

The POA changeover kit eliminates the sometimes unreliable oem POA and replaces it with a pressure switch that turns the clutch on/off to regulate the air outlet temperature.

Use R12 only for the lowest air discharge temperatures in ALL climates. Beware of inexpensive R12 substitutes as most contain explosive gases such as propane. Use crimped sleeves and the latest "barrier" hose and there is little chance of loosing that high priced gas.

Les