Help need to pull vacuum on A/C system...

[Cave Gimp]

I installed an A/C system on my Nissan truck. Its now time to charge the system, but I need to pull a vacuum and purge the system first. Does anyone know of a good A/C shop that will charge the system for a fair price, or have a vacuum pump I can borrow? I was putting too many miles and burning too much gas on my Rubi so it was time to make my old truck a daily driver in the summer heat. Any suggestions would be appreciated.

[Kyron]

Whats in there now??? Purge it with Nitrogren and then pressurise it and check for leaks.......

Then use the refrigerant to "push" out whats left of the nitrogren.....




......... Trust me, its a better way than 95% of the new houses being built around here:o

[Cave Gimp]

In there now is a mix of approx 78% N2, 21% O2, and 1% other stuff. :D In other words just air. I had the thing apart to replace the condensor and figured I might as well replace the o-rings while I was at it. In order to purge with N2 I would need to find some N2 I could purge with. Any suggestions there?

[ThumpAZ]

Welding/gas supply houses have N2, in many assorted bottle sizes, too.
I think he was talking about residential AC systems, though. Not automotive??

The shop next door to DesertFab (FirstChoice Auto) has the means I believe and won't rape you. Give Todd a call at 480 288-4213 and see if he can yell over the wall for them to talk to you or something. That way it's a DF customer coming to them for the perks that that situation entails :)

[JamesT]

I know you can rent pumps. I am not sure where though.

[UNSTUCK]

...Or you could just come by my shop...maybe on saturday... and use my stuff. Pump you down and charge you up, no problem.

[Kyron]

I think he was talking about residential AC systems, though. Not automotive??


Me or??? A/C systems are all the same (for the most part)

[yellow bad boy]

hope you didnt put the drier on already, if ya did you might as well go get another on and install it right before you pull a vacuum.

[UNSTUCK]

hope you didnt put the drier on already, if ya did you might as well go get another on and install it right before you pull a vacuum.


What do you mean?

[Cave Gimp]

The new one is still in the box so I guess I amsafe. Why would the vacuum kill the drier? How do you install the drier after the system is drawn down? You woudl have to break the seal and I would be back where I am at now?

I am soooo confused.

[UNSTUCK]

The new one is still in the box so I guess I amsafe. Why would the vacuum kill the drier? How do you install the drier after the system is drawn down? You woudl have to break the seal and I would be back where I am at now?

I am soooo confused.


If you don't know, the dryer is you AC system filter, along with the orifice (sp?) tube. Any time you do any parts replacement in the system, you should change out both of these. I'm not sure what Yellow Bad Boy ment by his comment, but you have to replace your parts at one time, then pull vaccum.

You can still come to my shop sometime and I'll show you how to do it all. It's easy.

[Curly]

The Drier contains Dessicant, which is the chemical that "dries" the refrigerant. This is the same stuff you see in stereo boxes that is labeled "Do not eat." Its purpose is to absorb any moisture that managed to get inside the sysetem.

Installing the drier too soon will allow air/humidity to contact the dessicant and basiclly "fill" it up. Then the drier will not be able to dry the refrigerant, this can lead to the system icing up at the orifice tube or txv. It can also lead to acid formation.

So, install the drier right before you are ready to seal and evacuate the system.
Pull a vacuum for at least 30 minutes to insure all the moisture is out. Be sure you add a few ounces of oil to make up for what was trapped in the old drier. Don't overdo it on the oil, and don't overcharge the system, or performace will suffer.

[Curly]

Duplicate post, sorry.

[Cave Gimp]

Thanks forall the help guys. Obviously A/C isn?t something I have much experience with. I have an o-ring kit arriving on Tuesday and then I should be able to completely seal it up and need to pull the vacuum before the drier is destroyed. Again thanks for all the help.

[UNSTUCK]

The Drier contains Dessicant, which is the chemical that "dries" the refrigerant. This is the same stuff you see in stereo boxes that is labeled "Do not eat." Its purpose is to absorb any moisture that managed to get inside the sysetem.

Installing the drier too soon will allow air/humidity to contact the dessicant and basiclly "fill" it up. Then the drier will not be able to dry the refrigerant, this can lead to the system icing up at the orifice tube or txv. It can also lead to acid formation.

So, install the drier right before you are ready to seal and evacuate the system.
Pull a vacuum for at least 30 minutes to insure all the moisture is out. Be sure you add a few ounces of oil to make up for what was trapped in the old drier. Don't overdo it on the oil, and don't overcharge the system, or performace will suffer.

Good to know one of us knows what we are talking about!:D

[ThumpAZ]

Me or??? A/C systems are all the same (for the most part)
I had never heard of anyone purging a automotive A/C system with N2.

[Cave Gimp]

Thanks for the help today Josh. The truck is still blowing cold air.