# Disable Auxillary AC on SUV



## svk (Mar 20, 2018)

One of the lines to the rear AC unit on my suburban has corroded and I do not want to spend the $ needed to replace the lines. Can this circuit be capped up by the condenser or does the loop need to be shortened? Just want to be able to run my front AC without the refrigerant leaking out of the line.


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## Bobby Kirbos (Mar 20, 2018)

If they put in shut-off valves to isolate the front and rear loop, then yes. I doubt that they did this due to the cost.

I would imagine that you can remove the rear loop from the circuit. You'll need to leak check, evacuate, then recharge the system. You'll likely need less refrigerant since the system is now smaller. A good gauge set will help. Watch the high and low pressure sides of the compressor. Liquid line pressure taps are just short of worthless.


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## svk (Mar 20, 2018)

How does one cap this? Can I use brass fittings? I mean I know that is not a perfect way to do it but it's about 1500 bucks to replace those lines.


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## Bobby Kirbos (Mar 20, 2018)

Cap, as in something like this?






Yes, they can be capped, but the biggest problem that you're going to run into is that most car A/C systems use aluminum lines instead of copper. Good luck brazing brass or copper to aluminum without melting the aluminum.


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## svk (Mar 20, 2018)

I was thinking a flare nut with a plug?


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## Bobby Kirbos (Mar 20, 2018)

I assume it's running R-134a. Check the pressure charts here...
http://rechargeac.com/how-to/ac-system-pressure-chart
The flare nut (I assume you're talking about a compression fitting) may be ok at those pressures. No guarantee it will hold for any extended period of time. I've never had good luck with compression fittings.


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## svk (Mar 20, 2018)

It is 134a. I believe that the pressure for this system should be around 40 PSI. I know that compression fittings are good for over 60 PSI but I too have had less than great luck with them. 

Going to fiddle with it tonight to see what I can figure out.


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## Bobby Kirbos (Mar 20, 2018)

svk said:


> It is 134a. I believe that the pressure for this system should be around 40 PSI. I know that compression fittings are good for over 60 PSI but I too have had less than great luck with them.
> 
> Going to fiddle with it tonight to see what I can figure out.



Good luck.


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## ChoppyChoppy (Mar 20, 2018)

svk said:


> It is 134a. I believe that the pressure for this system should be around 40 PSI. I know that compression fittings are good for over 60 PSI but I too have had less than great luck with them.
> 
> Going to fiddle with it tonight to see what I can figure out.




Pressure will be around 275-350psi. (Depends on air temp)


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## ChoppyChoppy (Mar 20, 2018)

svk said:


> I was thinking a flare nut with a plug?



this HTML class. Value is https://www.amazon.c

Well, it errors when putting a link. Dorman sells a kit. Napa, Schucks, etc likely carry it.


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## svk (Mar 23, 2018)

ValleyFirewood said:


> Pressure will be around 275-350psi. (Depends on air temp)


How do you figure? System says not to fill over 50 psi.


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## svk (Mar 23, 2018)

As a follow up I was able to splice in a chunk of line once I pinpointed the leak. The toughest part was working between the body and frame rails inboard of the rear wheelwell. 

It had corroded through where the clamp held the line to the bottom of the body. I suppose road salt got in there and wasn’t able to get washed out. 

Anyway I’m almost 24 hours past the fill and it is still blowing cold air so it’s a marked improvement from what it was.


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## ChoppyChoppy (Mar 23, 2018)

svk said:


> How do you figure? System says not to fill over 50 psi.



That would be the static pressure (pressure the system is at without the compressor running).

The compressor will get the high pressure side up to around 275-350psi. (Varies on ambient temp).

You should be seeing this on your guage set with the system running.

A/C hoses are generally rated for 500psi. What did you splice into the line with?


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## svk (Mar 23, 2018)

Tubing and flared fittings. It doesn’t leak so that’s all that matters.


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