Converting factory AC to use R134a

[jimbosprint]

Originally Posted by tdangle

I just got a reply back from Classic Auto Air for a kit which includes the Saden-style compressor, brackets, condenser, hoses, filter/drier and hardware to update and run R134. $800 + $190 for a rebuilt and calibrated POA valve and $60 for a expansion valve. Does this sound reasonable or can I save a few putting something together myself. Sounds like everything from the firewall forward.

Sounds about right to me.

[F.A.A.benny]

Originally Posted by tdangle

I just got a reply back from Classic Auto Air for a kit which includes the Saden-style compressor, brackets, condenser, hoses, filter/drier and hardware to update and run R134. $800 + $190 for a rebuilt and calibrated POA valve and $60 for a expansion valve. Does this sound reasonable or can I save a few putting something together myself. Sounds like everything from the firewall forward.

I can rebuild your poa valve and include a new exp valve for $160

[picklito]

Originally Posted by RedRoad

Can you post the link to the series?

Thanks

Um... ya. Is this where I say, "DUH?" Sorry about that. Photo #210

http://public.fotki.com/blazbk/blaze...er1.html#media

[Davidf]

Responding to thread topic (I did not read all the posts). Best I can tell, OP is converting from R12 to R134A. From the photos, it seems the original R12 condenser is being utilized. I also see a POA update tube has been installed. While this setup may work in milder northern or west coast environments, it won't work well when temps start to climb above about 90 degrees F. The R12 condenser just is not efficient enough at shedding the latent heat from the R134a refrigerant. An electric fan would help and should be considered a must. problem is, there is not enough space to fit a fan between the condenser and the hood latch support structure.

In my experience, the POA update kit is junk. You will feel it (air temp) every time the compressor cycles on/off which will be often.

Good luck.

[jimbosprint]

Originally Posted by Davidf

Responding to thread topic (I did not read all the posts). Best I can tell, OP is converting from R12 to R134A. From the photos, it seems the original R12 condenser is being utilized. I also see a POA update tube has been installed. While this setup may work in milder northern or west coast environments, it won't work well when temps start to climb above about 90 degrees F. The R12 condenser just is not efficient enough at shedding the latent heat from the R134a refrigerant. An electric fan would help and should be considered a must. problem is, there is not enough space to fit a fan between the condenser and the hood latch support structure.

In my experience, the POA update kit is junk. You will feel it (air temp) every time the compressor cycles on/off which will be often.

Good luck.

Old Air Products told me the condenser I got is the same one they sell with their aftermarket AC kits made for 134a. It seems to work above 90 degrees. Maybe it would work better with an electric fan.

[F.A.A.benny]

Originally Posted by Davidf

Responding to thread topic (I did not read all the posts). Best I can tell, OP is converting from R12 to R134A. From the photos, it seems the original R12 condenser is being utilized. I also see a POA update tube has been installed. While this setup may work in milder northern or west coast environments, it won't work well when temps start to climb above about 90 degrees F. The R12 condenser just is not efficient enough at shedding the latent heat from the R134a refrigerant. An electric fan would help and should be considered a must. problem is, there is not enough space to fit a fan between the condenser and the hood latch support structure.

In my experience, the POA update kit is junk. You will feel it (air temp) every time the compressor cycles on/off which will be often.

Good luck.

Quote:
Originally Posted by jimbosprint View Post
Old Air Products told me the condenser I got is the same one they sell with their aftermarket AC kits made for 134a. It seems to work above 90 degrees. Maybe it would work better with an electric fan.

That is a piccolo condenser, same as the one that Classic Auto Air has sold. They more than likely get their condensers from the same manufacturer. I saw and responded to your post on fb also about that condenser. The piccolo condenser is better than the factory tube and fin type condenser but not seen as better performing than a true parallel flow cond.

[F.A.A.benny]

Those vent temps will rise in traffic or slower speeds with a factory condenser. They all do. Electric fans will help though.

[RedRoad]

Any difference in quality between 4 seasons and AC Delco components? Price is almost double for Delco but most parts Ive received are made overseas these days.

[leddzepp]

Originally Posted by F.A.A.benny

Those vent temps will rise in traffic or slower speeds with a factory condenser. They all do. Electric fans will help though.

Agree 100%. I did R-134 in a previous truck with factory AC. Recalibrated POA valve, flushed system, swung a dead chicken over my head, etc. Had to be doing 70 on the freeway for it to get cold on just a "warm" day.

Went with R-12 on my next truck with factory AC. It blows snowballs out the vents in 110 degree temps, sitting at a stand still in So Cal traffic. Yes it costs more than R 134 but so what? You charge it once either way and you are done. The bottom line is you want cold air and with R 12 you get it no matter what. What good is AC if it don't work?? No hoops to jump through and "hope" it works in the end with R 12.

[70's luvr]

Is it possible to strip all of a R134 system from a newer vehicle to convert factory system over?

[Eddie H.]

Originally Posted by leddzepp

Agree 100%. I did R-134 in a previous truck with factory AC. Recalibrated POA valve, flushed system, swung a dead chicken over my head, etc. Had to be doing 70 on the freeway for it to get cold on just a "warm" day.

Went with R-12 on my next truck with factory AC. It blows snowballs out the vents in 110 degree temps, sitting at a stand still in So Cal traffic. Yes it costs more than R 134 but so what? You charge it once either way and you are done. The bottom line is you want cold air and with R 12 you get it no matter what. What good is AC if it don't work?? No hoops to jump through and "hope" it works in the end with R 12.

I agree, I used R-12 on the last factory system I rebuilt on a 71 GMC, and it blows 40 degree air out the vents on a 100 degree day, idling in traffic. I have never been a big fan of R-134, even in newer vehicles designed for it. R-12 is what these older systems were engineered for, and as long as I can still buy it, that's what I am going to use.

[picklito]

That's way more work than necessary.

[lugnuts09]

I have a 1969 c20 and am curious as if I should replace my air conditioning system or not? I bought the truck and the compressor has not been hooked up in years. Everything is original.

[F.A.A.benny]

I vote for restoring an original system. If staying with r12, flush, pressure check both the evaporator and condenser. Test the poa valve to make sure It isn't stuck. Check the screen in the exp valve. You can clean it with some brake cleaner. Replace the drier. They are cheap. Some reuse their hoses/lines if they are in good shape. Hoses should not have cracks. Buy an aluminum a6 replacement compressor. Use mineral oil. If going with 134a, replace original condenser with parallel flow condenser. Recalibrate poa valve. Some will say to replace expansion valve but an original will work fine with 134a. I'd replace the hoses. Use pag oil. All this can be done for less than an aftermarket system plus it all bolts in and you get to keep the fresh air option.

[lugnuts09]

Awesome, thank you for the help. The system I am looking at is on a 1970 c20 and he's selling it for $350. It's all original parts. I just don't know if the parts that I have are still good. Not sure how to test them. I have all of the parts, only thing I don't have hooked up is the compressor and not sure if it's still any good.

[F.A.A.benny]

Since you say your system is complete on your 69 c20, then I wouldn't spend the money for another system. You can use that $350 towards new parts like the compressor, drier and hoses with a little more $added to it. You can look for a local old school ac shop or I can test the parts for you. You'd have to ship them though. I restore factory ac/heater parts.

[lugnuts09]

Did you guys update the evaporator or keep it original? I'm redoing the stock a.c. system on my 1969 c20.

[F.A.A.benny]

Originally Posted by lugnuts09

Did you guys update the evaporator or keep it original? I'm redoing the stock a.c. system on my 1969 c20.

Replied to your pm. There are no updates to the evaporator if it's the same size. You can "update or upgrade" the poa and expansion valve setup by using a poa delete kit which most guys don't like or using an accumulator/orifice tube setup. Either way you may want to consider upgrading the steel a6 compressor to either a Sanden type or aluminium a6 replacement as those compressors are designed to cycle and they don't have the oil slinging issue that comes with the majority of steel a6 compressors.

[dmjlambert]

I don't know what a hi-lo switch is, but here is the wiring diagram

[kwmech]

I agree, you'll have to brush up on your terminology. When I converted my 69 to 134a, I also went with an updated cycling system and eliminated the POA valve. I also went with a newer style compressor that matches the one in my 91 Suburban, only it has the V belt.

[ricachon7]

Excellent! Thank you kindly for the diagram. I failed to mention that I have swapped in an ls engine and installed a Sanden compressor. I have all the original components there. I will be updating the POA valve, condenser, dryer and hoses. I've seen a lot of ppl put a binary switch in on the dryer. One wire goes to the compressor but cannot find information on what the second wire (off of the binary switch) goes to. It was my understanding the binary switch is the same as the hi-lo switch AND cycling switch. Perhaps these are not all the same and that might be my confusion. Thank you for your input.

[body bolt]

The switch is typically in series with the compressor clutch power; in the schematic that would be 14DG.

[dmjlambert]

I think it matters what you mean about "updating" the POA valve.

If you are talking about rebuilding the POA valve and recalibrating it to work with R134a, then you would not need to cycle the compressor and that means no binary, hi-lo, or cycling switch. The compressor doesn't cycle.

If you get rid of the POA valve and put in a POA valve eliminator, the POA valve eliminator has 2 terminals on it and you wire that up to interrupt the power going to your compressor, and the compressor cycles. So the wiring would be as shown in the wiring diagram, except you would run the compressor wire to one terminal the POA valve eliminator, and the other terminal on the POA valve eliminator connects to your compressor. That's the way mine is wired. The POA valve eliminator on mine switches the compressor off if the pressure is too high or too low.

My dryer came with a plug that can be removed and a switch to install in that plugged port. I did not use it and Original Air, who sold me my A/C kit, told me I don't need to use that, just wire the POA valve eliminator in-line with the compressor wire.

[ricachon7]

TheBandit has an excellent video on youtube (https://youtu.be/jNUb-GDWz4Y). I was planning on doing what he has done except I do not have an ambient temperature sensor. His setup hooks up the ambient temperature sensor to the compressor clutch. I don't need that since I live in AZ but I still need to trigger the compressor. I will post a diagram to show what my setup should look like and ask for feedback. Based on what others have said about problems with the POA eliminator valve, I am inclined to rebuild and recalibrate the factory POA. That being the case, I wouldn't need a cycling switch but I still need to wire the compressor in line with 14DG as the trigger, correct?

[dmjlambert]

14 dark green wire sends power to the compressor clutch. I don't know if I would call that a trigger, but it does turn the compressor on when the A/C is switched on. In the factory setup, the 14 dark green wire gets 12V when the key is on, the blower is not off, and the middle slider on the A/C control panel is all the way to the left.