93 F150 r134a Conversion - Need Help!
 

Hey this is my first time posting here, but I need some HELP!

I have a 1993 F150 xlt with a 5.0L 302. I just completed my AC Conversion, but the AC is not blowing as cold as it should and my guage readings make no sense (this is my first attempt at AC work so I may just not know what I'm looking at...)

What I've done so far:
New AC Condenser from a 95 f150
New Low Pressure Line from 93 f150
New Compressor from 93 f150
(Came with 3oz pag oil, I added an additional 4oz)
New Dryer from a 95 f150
New Evaporator from a 93 f150
New High Pressure Line from a 95 f150
New Red Orifice tube I set a vacuum pump on the system to -30psi, I then shut off the pump and let it sit for an hour and no change in pressure (assuming that means no leaks). I then ran the vacuum pump for 45 mins to clear the system
I Added dye and 33oz of r134a

Now the ac blows cold-ish air, but not as cold as it should...here are my guage readings after replacing everything.

*Ambient temp under the hood (105f)*
After the system sat turned off for an hour and the truck turned off:
Low: needle was pinned max at 350+
High: 150
​​​​​​Truck on with AC on full blast:
Low: 50psi
High: 50psi

Right after turning the truck off:
Low:
​​​​​

something does not look rite. i use this gauge to fill ac systems:
https://cimg0.ibsrv.net/gimg/www.for...378d1e7ad5.jpg
one thing to note, ambient temp is outside air temp, NOT under hood temp.

What is the R-12 refill capacity? You use less R-134a than R-12. How much did you put in? Here is a chart that I found online.

https://cimg2.ibsrv.net/gimg/www.for...62961404c.jpeg

Sorry for the delay, I had to leave town unexpectedly. This is the chart I have been using, it says the 93 f150 needs 44oz of R12 freon. So I added 33oz of the R134

Well, that can't be right- especially if your running pressures were lower.

The system should equalize after the truck sits for a little bit.

Easiest answer is that your gauges are way wrong.
Harder answer is that you have a plugged line/ valve in backward/ etc somewhere in there.

But that doesn't explain why your running pressures are so low...

t
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