DIY: R-12 to R-134a Conversion (How To)

Doat

Active Member
Feb 6, 2012
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Not too bad, if I can do 2+ months of work I can handle a day lol

Just remembered I don't have a 24 or 27mm wrench, time to buy some new wrenches with socket ends.
 
May 18, 2007
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Would you be able to use a parallel flow condenser with R12 without reducing performance of the system?

I read somewhere that the speed of the coolant flow (the through put) could be reduced with a parallel flow condenser which apparently shouldn't be good with R12.
 
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JDMMA70

Active Member
Dec 4, 2006
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Mk3turbo_newb;1929620 said:
Where In the world did u manage to find the R-12? I'd like to completely swap everything over but it's not within my reach at the moment.

The store. Freeze 12 isn't R12. You can still buy R12 its not hard to find.
 
I really want to have this no AC problem fixed. This (ma70) at the moment is my only source of transportation and trust me I don't want my daughter and wife riding around with no AC this summer. I'm more than willing to take on the task, but honestly it's a bit of a daunting task especially since I have never messed with an AC system before. I have a buddy that is willing to let me borrow any and all tools or the task. I think the only piece of equipment that he might not have is a compressor.
 

CyFi6

Aliens.
Oct 11, 2007
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www.google.com
Kristian_Wraae;1929612 said:
Would you be able to use a parallel flow condenser with R12 without reducing performance of the system?

I read somewhere that the speed of the coolant flow (the through put) could be reduced with a parallel flow condenser which apparently shouldn't be good with R12.

PF condenser will work well with R12 refrigerant and improve performance. I have a PF condenser from American Condensers plus a large Spal pusher fan in my Supra running R12 and it has been working well.

http://www.ackits.com/c/Parallel/Parallel+Flow+Condensers+-+Aluminum.html

"When converting from R12 to R134a using a Parallel Flow model condenser greatly improves performance. Parallel Flow condensers can also be used with R12 and alternative refrigerants."
 

yhatzee89

Joe Yantz
Aug 31, 2012
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JDMMA70;1929685 said:
The store. Freeze 12 isn't R12. You can still buy R12 its not hard to find.

Is R12 better? (aside from the environmental part) if so I would gladly just stick with what my system is designed for if it makes it work better. Although I've never had AC in a Supra so anything is better at this point lol
 

jetjock

creepy-ass cracka
Jul 11, 2005
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Redacted per Title 18 USC Section 798
I remind those new to MVAC it requires tools and skills not possessed by the typical backyard mechanic. At worse you can be hurt but more likely you'll end up with a system that works only to require extensive (read expensive) and near complete rebuilding within a season or two. The only way to avoid this is by thoroughly understanding everything involved and doing it right the first time. I can't stress that last part enough. If you don't have it 100% down pat the job will come back to bite you and it won't be cheap.
 
May 18, 2007
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CyFi6;1929784 said:
PF condenser will work well with R12 refrigerant and improve performance. I have a PF condenser from American Condensers plus a large Spal pusher fan in my Supra running R12 and it has been working well.

http://www.ackits.com/c/Parallel/Parallel+Flow+Condensers+-+Aluminum.html

"When converting from R12 to R134a using a Parallel Flow model condenser greatly improves performance. Parallel Flow condensers can also be used with R12 and alternative refrigerants."

It is just that I found this on a Mercedes forum:

the R12 refrigerant can use all the help it can get to remove heat from the cycle, but a parallel flow condenser has one drawback, there is little room for liquid storage. the fact that a reciever dryer is part of the system helps, so it SHOULD improve the situation. the problem I can envision is this: R12 needs compression, heat removal, and flow velocity to function properly. compression and heat removal are fine with a PFcondenser, but velocity is massively reduced. I think it should improve both efficiency and cooling capability to move up to the PF, but velocity may be deminished enough to cause a reduction in capacity.
before going to that expense, I'd remove the existing coil, flush it free of residue, and chemically clean the fins and tube surface to get maximum from it.
if this doesn't help, only then would I consider a PF
if your sig pic is your car, at least you have a light color paint on the car. I'd get ALL the windows professionally tinted the max you are allowed, and do what is allowed on the front as well.

So in theory smaller room for liquid and lower flow speed and maybe higher pressure.
 

JDMMA70

Active Member
Dec 4, 2006
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Just the evap, and the lines for the block style txv. CyFi6 swapped in an entire 89+ system including the 88+ lines that move the drier over to behind the overflow. Since youre there at that point, id suggest flushing your lines, and resealing. The 89+ evap units are more efficient, from my experience. The evap boxes are the same and should be.
 

gtsfirefighter

SM Expert on White trash
Sep 26, 2006
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Going to add a little kudos to this thread Derek, aka JDMMA70.

I drove my 88 Supra down from Fort Worth to Katy, Tx with parts in the hatch so that he could repair my a/c. My expansion valve had taken a dump and the compressor seemed to be dying a slow death. So a brand new compressor, drier, and expansion valve were purchased, along with an o-ring kit, new and better fittings and refrigerant. I had a shop evacuate the system for me the day before at no charge to me. The car already had a parallel flow condenser courtesy of the previous owner Emilio Rescigno.


Anybody hesitant to switch over to R134a don't be. As you can see in the pic below it was blowing plenty cold.

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nshuffle

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Aug 6, 2014
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Derek's the best. He got my a/c working in no time. 38 degrees out of vents, black car, 105 degrees heat index outside with car in idle. HIGHLY RECOMMENDED. Great guy to do business with. He has his a/c license too, so that's assuring. Thankyou.
 

Rollus

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