87-4runner

My 87 4runner is blowing " cool" air...
no leaks, who knows how long it's been since any freon was added.
It's still the R12 ...
Do I have a shop add FR12 or convert to 134?
what have yall done?

dbittle

I went back with 12 on mine last year. It’s what it was designed for. It was expensive to fill though.

Jimkola

I bought a O-ring kit and replaced all of them. It really wasn't bad to do. Even dropping the evap box was pretty easy. Back in the 80's most trucks came without a/c, and dealers would install complete a/c kits, so Toyota made the design pretty straight-forward. My evap was full of leaves and other crap, so it turned out to be a good thing that i pulled it. The green O-rings i used are supposed to be compatible with either Freon. We shall see. I filled with R-134 in case I had a leak, then decided to leave it. I knew the risk to the compressor seals, but two years later still blows cold. I had priced a reman Denso compressor just in case, and it was pretty reasonable if I needed one.

I borrowed a vacuum pump and charge manifold from a friend. Using a kitchen scale, it wasn't hard to recharge following the FSM.

maxvp01

i’m going to be converting to R134A in my 1989 pickup. i had to pull the entire interior out earlier this year to weld a patch in the cab, so i went ahead and resealed the entire system with closed cell foam, and replaced the evaporator and the heater core.

everything below this is why i personally would change all that stuff out, and convert to R134A.

when i had to take ducting and all that out of my truck when pulling interior out, the closed cell foam from the factory was in ROUGH shape and pretty much non existent. the purpose of this foam is to seal the system from leaking air.
These parts have foam in the system on my 89’ pickup:
-Blend doors
-Ducting
-Heater Core and Evap Boxes

also due to the lack of cabin filter in these trucks design, debris will find one way or another into this system. this will get clogged in the evaporator and heater core fins. the purpose of these fins on the evaporator is to absorb the heat inside the cabin and transfer this heat to other parts of the system to dissipate it (condenser- important these fins are not folded over due to rock chips or people pushing them over)

Components with fins:
-Condenser
-Heater Core
-Evaporator

i can explain the theory of the AC system more if you want, but basically all these parts go hand in hand when calculating the efficiency of the system. The higher the efficiency, the better the cooling.

so R12 was phased out about 2 decades ago. it’s harder and more expensive to come by. this is the reason why i am going to convert to it.

For reference:
I have a 2004 Honda CR-V freshly charged with a good sealed system, and a 1993 Lincoln Towncar with a FRESH charge of R12. The Lincoln’s foam in the ducting is very aged, and could probably use a resealing, and the evaporator could be cleaner. My Honda with the R134A I would say cools noticeably better in the 100 degree summers.

Fun fact:
I have actually worked on a truck that would not heat in the winter for my friend. He said none of the shops could figure it out. The problem turned out to be his evaporator being clogged with dirt. Just think about what a slightly clogged evaporator would do to the efficiency of the system!

87-4runner

Thanks gents... I'm listening.

scope103

Here's what I know about changing from R12 to R134a: https://www.yotatech.com/forums/f116...-r134a-284801/

Paul22RE

The PO (in Arizona) of my truck converted to R134a and was not happy with the cooling ability and switched back to R12.

SheepishLion89

I'm running R134a. R12 might be a tad cooler but R134a was great for me and helps when going to shops to fill in the refrigerant. I.E. its more widely available and accessible in general. For me, ease of access to parts, shops was better than a few degrees cooler.

swampedout

R12 is a more efficient refrigerant but 134 is worth the switch if youre going to dig into the system. But clean the system as thoroughly as you can if you open it for the switch.