Loss of AC refrigerant when outside temps drop to -40

[Bluestream]

Was reading on a site recently that when outside temps drop to -35 to -40 and vehicle left outside, AC compressor seals can shrink allowing refrigerant to escape.
Problem then not found until warm weather returns.

Has anyone encountered this issue?

 

[Chris142]

Makes sense. Also when a system sits for weeks or months without being used the oil runs off the seals and it leaks out. Very common here on motorhomes and cars that sit all winter

 

[stangguy]

Makes sense. Also when a system sits for weeks or months without being used the oil runs off the seals and it leaks out. Very common here on motorhomes and cars that sit all winter

I have wondered about that on my cars that sit all winter. I did used to have a 1980 Gmc pickup that was a use it only when I had something to haul, that would sit for long periods during the winter, and the A/C always worked fine on it for all the many years I had it. But it never sat for maybe a couple months at a time without being driven. Now I have a 98 mustang that I stopped using it in October, and not planning to run it again till maybe April. Should I drive it sometime when there is some nice weather now, and get it well warmed up and even use the A/C???
It does sit in my attached garage that never gets below freezing in there, rarely below 45f actually if that makes a difference.

 

[Lubener]

I will watch out next time it gets -40 degrees.

 

[CDX825]

At that temperature R134a is only at about 7psi. So the chances of it leaking should be way less or at least I would think.

 

[SwampSurvivor]

My Subaru isn't even able to hold refrigerant on a normal summer day. Ugh. Rant over.

We've had some really cold nights like that in the past. Anything else I've had with R134a never lost refrigerant. My old Focus was 8 years old and still had ice cold AC after a few -30 nights.

 

[mk378]

At that temperature R134a is only at about 7psi.

psi absolute.

At -15 F the vapor pressure of R134a is approximately atmospheric pressure; below that it becomes less than atmospheric pressure. At -40 F it is close to zero. Freezers running R134a operate at negative gauge pressure on the low side.

 

[wing0]

My Subaru isn't even able to hold refrigerant on a normal summer day. Ugh. Rant over.

We've had some really cold nights like that in the past. Anything else I've had with R134a never lost refrigerant. My old Focus was 8 years old and still had ice cold AC after a few -30 nights.

I'm having same issue with my Subaru.
I was going to find the o-rings for the hoses and replace them.

 

[SwampSurvivor]

I've been through two compressors, two condensers (as in number three for both) , a set of o rings and had the high and low pressure lines replaced.

 

[Chris142]

I've been through two compressors, two condensers (as in number three for both) , a set of o rings and had the high and low pressure lines replaced.

What year is the car?

 

[SwampSurvivor]

2018. They just kept throwing parts at it to get it out of warranty. Now that it's out of warranty, it's my problem.

 

[Chris142]

I wi

2018. They just kept throwing parts at it to get it out of warranty. Now that it's out of warranty, it's my problem.

I wish you were closer. I would like to spend some time on it.

 

[CDX825]

psi absolute.

At -15 F the vapor pressure of R134a is approximately atmospheric pressure; below that it becomes less than atmospheric pressure. At -40 F it is close to zero. Freezers running R134a operate at negative gauge pressure on the low side.

Your right. I had the pt chart set to psi absolute and didn't even realize it.

 

[SwampSurvivor]

I wish you were closer. I would like to spend some time on it.

For sure! It needs a set of eyes that actually wants to fix the problem. Not run out the warranty.

I have my suspicions on what it needs. The fact that its had two compressors fail, but the system was never flushed and the evap core never changed means its full of junk and going to continue to have problems.

LUCKILY, when I pay to have to have the evap core changed, it's accessible by taking off the glovebox. The dash doesn't have to come out

 

[Chris142]

For sure! It needs a set of eyes that actually wants to fix the problem. Not run out the warranty.

I have my suspicions on what it needs. The fact that its had two compressors fail, but the system was never flushed and the evap core never changed means its full of junk and going to continue to have problems.

LUCKILY, when I pay to have to have the evap core changed, it's accessible by taking off the glovebox. The dash doesn't have to come out

You do not normally have to replace the Evap. The condenser and expansion valve are good filters lol. I would open it up and back flush the evap into a glass jar to see what is in there. If it's not too bad I would continue to flush it until it came clean. But that is you're choice.

I would replace the compressor,condenser,dryer and expansion valve for sure. Only a new compressor,no rebuilts.

 

[Jetronic]

At that temperature R134a is only at about 7psi. So the chances of it leaking should be way less or at least I would think.

or more... seals require pressure to press them against axles. less pressure and harder seals combined with smaller axle dimensions....

 

[SwampSurvivor]

You do not normally have to replace the Evap. The condenser and expansion valve are good filters lol. I would open it up and back flush the evap into a glass jar to see what is in there. If it's not too bad I would continue to flush it until it came clean. But that is you're choice.

I would replace the compressor,condenser,dryer and expansion valve for sure. Only a new compressor,no rebuilts.

I believe the expansion valve is full of crud that's for sure. I was mistaken in terminology, got the two backwards.

 

[Jake_J]

As somebody who's lived in various parts of Canada where -35 C to -40 C is a normal occurrence I'd say it's not really a problem. Sure it could happen but folks in Northern Alberta or Labrador aren't recharging their AC systems at any greater rate than in relatively mild Southern Ontario.

 

[atikovi]

Was reading on a site recently that when outside temps drop to -35 to -40 and vehicle left outside,

I can't imagine any place that gets down to -40 would have much need for a/c in the summer.

 

[OVERKILL]

I can't imagine any place that gets down to -40 would have much need for a/c in the summer.

But it does! Winterpeg gets extremely hot in the summer and insanely cold in the winter.