2004 F-150 Heritage AC

[Tim]

If you have Nylog, use it on all connections.

[kenlou]

Well, it looks like I could not keep my mind on what I was doing:
I proceeded to flush the evaporator, and when I was done, I hooked the lines back up and realized afterwards that I forgot to dry it out with air and I also forgot to add one and a half ounces of pag to it.

Is it possible that if I ran a vacuum for long enough that it would get that moisture out of that evaporator or do I have to disconnect everything and do it all over again?
And if I have to do it all over again, then I have to replace the dryer also correct?

[JohnHere]

Well, it looks like I could not keep my mind on what I was doing:
I proceeded to flush the evaporator, and when I was done, I hooked the lines back up and realized afterwards that I forgot to dry it out with air and I also forgot to add one and a half ounces of pag to it.

Is it possible that if I ran a vacuum for long enough that it would get that moisture out of that evaporator or do I have to disconnect everything and do it all over again?
And if I have to do it all over again, then I have to replace the dryer also correct?

Sorry, Kenny. This weekend, I got busy on another project and couldn't respond to this and your previous post.

But no, the vacuum pump won't pull that much remaining flushing solvent out of the evaporator. You'll have to disconnect the lines again and thoroughly blow-out the evap using your clean and dry shop air until you see no more droplets and/or atomized solvent coming out. Then add the PAG oil and reassemble.

The R/D is a question mark. If you didn't run the system after you flushed the evap, then you can probably get away with using the one that's already installed. But Best Practices state that the R/D should be replaced every time the system is opened. Your choice.

If you DID run the system with the flushing solvent still in the evap, then we have more problems to deal with. Running the system at that point would have circulated the solvent throughout the system, which means everything now will have to be flushed and air-dried, except the compressor, which can't be solvent flushed. The compressor is properly flushed with the same PAG oil you use in the system—in this instance, do so multiple times to ensure that you get out all traces of the solvent. I'm afraid that the parallel-flow condenser will have to be replaced again because it can't be effectively flushed.

I have a few more questions: I purchased a gallon of your AC flash flush. That’s what I’m going to use.
When I back flush that evaporator, just to doublecheck that outlet side goes to the dryer, correct?
Should I plan on using 90 psi when I do that backflush?
And when I connect both lines to the evaporator, is it all right to use nylog blue on those three O-rings on each one of those lines or should I just lubricate it with the pag oil?

Backing up to your previous post:
ACKits.com carries the "good stuff," so that indeed is the best flush solvent to use.
Just the opposite...the outlet side of the evaporator is the other larger diameter line. The thinner high-pressure line is the liquid line that feeds refrigerant to the TXV and then to the evaporator, and it runs from the R/D to the TXV/evap.
Nylog Blue is ideal to use on all o-rings and mechanical connections.

[kenlou]

The only thing I did, I started to run a vacuum for a few minutes and I realized what has happened and I shut that off
That wouldn’t circulate anything correct?

[JohnHere]

That's good. No, it wouldn't circulate the solvent.