www.Spark-Plug.us Fix It Section...

134A A/C Retrofit

PART 1 Introduction

Here's a quick guide on store bought A/C conversion kits. They will convert your existing (pre 1993) R12 refrigerant system to the new 134A. This will only work if your current R12 system is fine (no major leaks) but needs refrigerant.
If you have comments please E-mail me at: SPARKPLUGS@LYCOS.COM .

Warning... it is Illegal in the USA to expel R12 refrigerant into the atmosphere,
you must have a certified A/C specialist remove it...

Sparkplug's Retrofit info...
Summer 2001
In 2001 I had Used a $49 Retrofit Kit (that I describe here) on my 87GT & it worked great!
I had hardly any R12 left so compared to the $180 cost to put R12 in I went for the new stuff.
Then next
It was still leaking so I put a can of Stop Leak with Red color so it would show where it leaks...
I worked stopped the leak & stoped the A/C from working :( ...I should of known.
I believe I may have clogged the (probably allready clogged)
Orifice tube, so I did the upgrade the right way see A/C Part 2


- First you must determine if your A/C is not working due to Low Refrigerant or other reasons.
- Some other reasons are: compressor failure, bad pressure switch, or leak.
- Usually A compressor that engages on & immediately off, or not at all is an indication of low pressure.

- Get a pressure test (how much R12 is left?). If you need to add more than half capacity you might consider the 134A.
- If you only need a little R12 then Adding R12 may be your best choice.


Determine what the cost of adding R12 would be (its very expensive)
Compare a usual R12 fill up at about $180.
To: the retro kit (includes everything) at about $49.
The cans of 134A also sell for $5.99 each for future fills.


Also its a good idea to replace all the A/C lines & orings with new 134A ones if you want your a/c working for years.
You can do that yourself but need special line lock tool to unlock the lines & have your system vacuumed to remove moisture.

Info on the Refrigerants:

R12 VS 134A

-R12 came in all A/C's from the 70's to about 93 (check your manuals).
-R12 is a CFC known to damage Ozone Layer, Its getting harder & more $$ to get.
-R12 can only be removed, purchased or added by a certified Professional.
- Refrigerants are not compatible with each other!
-134A is a new Environmentally Friendly refrigerant that replaced R12 from '93.
-134A Runs at higher pressure that R12, use 85% of what is recommended for R12.
Anyone know what the capacity is? ? ?


O-Rings - Orifice Tube - ...

-134A's Molecules are smaller than R12, it was thought that it would pass through R12 O-ring. ( the manufacturer of the Retro Kit states that this is not a problem due to the O-rings absorption of (r12)oil during its years that block the smaller R134A as well.) If you have a new R12 system you may have to change O-rings.
-134A O-rings are Green colored

Info on the Retrofit:

- 87-93 Mustangs have Large compressors that will handle the higher 134A pressure.
- You must have the system emptied, (by certified..., you know)
- A/C system does not have to be opened or touched in any way other than removal of R12
- Get the kit(box) with adapters, hose, 3 cans of 134A, and oil.
-The 134A Retrofit kit uses Ester Oil which is compatible with R12 oil. (Again, you must remove all R12, but even after removal of refrigerant some old oil will stay in system).

- Pag oil is NOT compatible with the R12 Oil...you must completely flush out your system if you wish to use Pag oil. Pag oil comes with factory installed 134A A/C systems...use PAG Oil only in the cars that came with 134A from factory post 1994.

- You have to use special Ford a/c line removal tools if you want to replace a/c lines. can be bought from auto part stores...not costly.

- The line that the Orifice tube is in is the lower "Liquid Line"... It is the bottom one from the condenser & goes into the firewall. About $30