R12 to R134 conversion results

I

Idwitheld-1`

New Member
Nov 30, 2003
335
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Portland Oregon
#1
Took the plunge and did the AC conversion at the local Ford dealership.

Today it was 100 Fahrenheit outside (in the shade).

Car interior measured 122F after sitting for 9 hours in the sun.
Running max AC and blower on max the coldest temperature (measured inside the vent) was 52 degrees F.

Cabin temperature got to 81 deg. as measured about 18 inches away from the vents shoulder level).

Engine temperature ran all the way up to the "N" in normal (1 tic below 270). This was in stop and go traffic with the total trip time about 1 hour. Temperature of car held steady there. I was not happy about this and kept me on edge...but the car ran fine.

Oh and New replacement radiator, water pump, t-stat and hoses all less than 6 months old. Twin black magic 12 inch cooling fans. 55mph cruising in OD (1800 rpm) did NOT bring the temp down afte 10 minutes. Is this normal for a stock block 93GT 302 with AC?
 
#2
On mine with R134a, the air out of the grill is 52-48 degrees. I have a 3 core copper/brass radiator & water temps run 180 degrees in 95+ temp in central Florida.
 
#3
How cold did the a/c feel? Also how much did it set you back? I did the conversion in my drive way, just picked up the lowside adapter and a can of oil and 3 cans of R134A blows ICE cold, especially for Florida.

As far as over heating, dont trust the stock gauge, but still that is high. Did it boil over or anything? I found when I had that style electric fan (proform) if I left it running while driving it wouldn't cool down, I had to turn it off w/ a switch when I started moving. Next time try turning the fan off if you have a switch. I ended up buying Ramcharger dual fans, which are awsome.
 
#4
cardudeusa said:
How cold did the a/c feel? Also how much did it set you back? I did the conversion in my drive way, just picked up the lowside adapter and a can of oil and 3 cans of R134A blows ICE cold, especially for Florida.

As far as over heating, dont trust the stock gauge, but still that is high. Did it boil over or anything? I found when I had that style electric fan (proform) if I left it running while driving it wouldn't cool down, I had to turn it off w/ a switch when I started moving. Next time try turning the fan off if you have a switch. I ended up buying Ramcharger dual fans, which are awsome.
Click to expand...
Do you turn your Ramchargers fans off when you are on the highway or what?


BTW, is it really worth it to change over?

Dave
 
#5
Oh, and one more thing. With the swich on MAX you are recirculating inside air, which as you stated was 122*. You will find if you switch it to the normal a/c setting it will get cooler a LOT faster. On normal if sucks air in from outside instead of trying to cool the hot cabin air. Put both windows down for 2 or 3 minutes with it on just normal a/c, let it blow out all the hot air. Roll the windows up and filp it over to MAX. This should ya get it cooler.
 
#6
92GreenGT said:
Do you turn your Ramchargers fans off when you are on the highway or what?


BTW, is it really worth it to change over?

Dave
Click to expand...
Yeah, only time I need them is when I come to a stop. All other times it stays right at 180-185*. MUCH better than the fan I had, and with aluminum heads, it wasn't worth the shot of overheating. The proform fan kept it around 210-220*, not what I wanted with those heads. With the Ramchargers I have yet to need to use the high speed setting.
 
#10
Good idea sirsureshot, but I think the extra hp you would get out of it, would in turn be taken right back by the power it would take to run the compreser.
Unless some one ever came up with a way to run the comp electrically.
Like some of the water pumps out ther.
 
#12
cardudeusa said:
How cold did the a/c feel? Also how much did it set you back? I did the conversion in my drive way, just picked up the lowside adapter and a can of oil and 3 cans of R134A blows ICE cold, especially for Florida.

As far as over heating, dont trust the stock gauge, but still that is high. Did it boil over or anything? I found when I had that style electric fan (proform) if I left it running while driving it wouldn't cool down, I had to turn it off w/ a switch when I started moving. Next time try turning the fan off if you have a switch. I ended up buying Ramcharger dual fans, which are awsome.
Click to expand...

did not boil over. I must be tired. Why would turning the fan off aid cooling at speed? Its a puller...does that not help....I must be confused. If I put a switch on it, I'll forget to switch it on again and fry the motor....I guess you ony have to forget once....and I surely will.

Parts were 400 bucks, labor was 300. Plus diagnostic fee and disposal fee....just under 800 bucks. My comfort was worth it (god 103 is hot!!!)
 
#13
hey ID. :)

remember that the puter kills the a/c at 242* (IIRC). so if you still had a/c, you were not running THAT hot.

as i always do, i recommend a decent gauge (even a 10 buck parts store one).

you really need to know where you stand, esp if you are gonna make troubleshooting decisions based on a gauge.


FWIW, i run 170-190 in 110* heat. turn on the a/c and i can creep up to 210 in traffic. i shut the a/c off at that point, for my sanity and to ward off detonation.

it will cool back down to 180 in a few minutes after that.

i would have said that your radiator is not doing too hot (or is too hot), but since it is new....

a quick thing to try - get your hands on a 180 mr gasket t-stat. i tried a parts store 180 and then went to the mr G later that week. seemed that temps dropped ~10* or more in similar situations. the Mr G is a sweet stat - hold one up to a parts store one, and you will see (opens fully sooner, balanced, bleed hole, and all that). i always recommend them based on my experience.


have you driven in similar heat w/o the a/c (i.e. before you got it fixed?) to see if temps were the same? is the a/c load (pulling air out of two coils) too much for your fans (i dont know snot about the CFM flow on anything but a mark 8)?

if you actually were not running as hot as you think, you might not be too bad off. as you know, with ambient temps like that, the delta across the coils is not gonna be huge (and moved up in the spectrum).
im just tossin out ideas. good luck bud!
 
#14
So for a total of 800 bucks whats involved in doing this?? i didnt even think ford would work on older cars now. I have a 88 bronco and Ford wont even touch it "lame" but if they could so my 86GT i would gladly pay for it. For parts do they basically install a new AC system?
 
#16
Idwitheld-1` said:
did not boil over. I must be tired. Why would turning the fan off aid cooling at speed? Its a puller...does that not help....I must be confused. If I put a switch on it, I'll forget to switch it on again and fry the motor....I guess you ony have to forget once....and I surely will.

Parts were 400 bucks, labor was 300. Plus diagnostic fee and disposal fee....just under 800 bucks. My comfort was worth it (god 103 is hot!!!)
Click to expand...

I don't know for sure why it wouldn't cool with the fan on while driving. The only thing I can think of is maby it wasn't pulling as much air as "could" be moved through the radiator and may have been blocking the flow. Strange, but I watched it happen on both my stock and autometer temp gauges many times.

For $400 worth of parts, just about everyting on your a/c system must be new!
 
#17
R134 runs at a higher pressure than r12. R12 is more efficient than 134. But with the ozone and the price, a 134 retrofit is well worth it. There is an additive called freeze 32 for older cars doing a conversion, I've seen the results, it works well, it will make your ac 5 degrees colder. If you do the conversion yourself, you will never get the results you want if you don't have a vacuum machine and didn't change the drier.
 
#18
Just converted to R134 myself...I had access to a R134 Professional Vac/Charge Machine since I recently worked at a New Car Dealership. I purchased the Retro fittings and Ester Oil (R12/R134 compatible) at you local N*PA store for about $25-$30. Vac'ed the system down for 30-45 min. Charged the car with about 2lbs. R134 versus the 2lbs. 2oz. of R12 since R134 operates at a higher pressure. Hi-side press is about 270psi and blew 50 degrees @ idle in the shop....NOT too BAD! :p
 
#20
He went to a shop, and they probably replaced about everything. The only thing you need to change really is the drier. But, he should have a warranty and if you can't do it yourself, that's the price you pay
 
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