New to the group and my 68 RS convertible.

Factory air previously converted to 134a wouldn’t cool but a few degrees so switched it back to R12.

Now going down the road temp fluctuates from low of 62 to high of 72 and back again.

Low side pressure at 30 and high side 250.

Used to be AC tech 30 years ago so know enough to be dangerous but not enough to fix this problem.

Heater core disconnected.

I am in FL so please don’t say just put the top down lol!

Pressures

 

OH chit
40 year AC service tech myself and a Ford chassis master but hell
Can't really switch back unless you replace every component
Looks like you got it flushed out good enough, and must have a supply of R12 like me
However
Just replace the capillary tube / expansion valve and try it again
Your orifice is the problem and switching the oils twice probably did not help
Capillary tube / expansion valve was most likely the fault all along
Pressures look good / perfect

 

Thanks I just bought the car so didn’t know what was in it but the expansion valve looks new but that’s where I am looking to next.

 

You have a recycler? I take it
Sometimes I suck the stuff out a few times and see how much oil comes out on the problem children
I see Moab rock crawler Jeeps around here that have God knows what in them and tons of oil
Getting some of the excess oil out helps sometimes

 

What recycler do you have that allows you to see how much oil comes out? Looking to buy one btw cause I still have a couple of R12 cars.

 

I have a Snap-on ECO 12 and a ECO 134a (bought new in 2000 IIRR)
After each recycle you can drain the oil separator and see what amount came out
I have a graduated cylinder in the cup
Not accurate as hell but you can see if a bunch comes out
Then I just leave it out if I feel the need