Air conditioning recharge in winter?

Post by **FireFox31** » 09 Nov 2017, 16:12

I'm planning to replace my 2000 V70 heater core this winter and would like to replace the A/C evaporator at the same time. Is it possible to recharge the air conditioning unit in the winter? Isn't the operational coolant pressure related to ambient air temperature?

Or is there a way to replace the evaporator (and accumulator, maybe the compressor and condenser) without immediately recharging the system? As I understand, the internals of the A/C system can't be exposed to air for more than a day or so before it ruins them.

I'm pretty sure my heater core is leaking, so I don't want to put it through another cold winter and risk it breaking when I really need it. Thanks.

Post by **misha** » 09 Nov 2017, 16:42

Just let the professionals to take care of your ac system.....and YES....you can recharge and service ac system in winter,but you don't need to.
You can wait untill summer without problems,just make sure to "close" system properly after evaporator replacement.
Ac evaporator isn't prone to failure on these cars,and if it doesn't leak,i would leave it alone.
Mine is original and ac is fully functional.

Post by **rspi** » 09 Nov 2017, 16:47

I keep my AC charged year round. It is critical in keeping the windows clear anytime you have humidity or icing.

Post by **FlyingVolvo** » 09 Nov 2017, 16:56

Just FYI, replacing the heater core is a relatively simple task. Replacing the evaporator however, involved completely removing the dash and a ton of other parts... it is pretty difficult and very time consuming.

Post by **misha** » 09 Nov 2017, 17:10

rspi wrote: 09 Nov 2017, 16:47 It is critical in keeping the windows clear anytime you have humidity or icing.

Icing...that's interesting...since compressor will not turn ON when outside temperature is below 2 degrees Celsius.

BeachWagon · Post by **BeachWagon** » 10 Nov 2017, 08:55

You can charge in the winter. If you so decide to take on the replacement, be sure to evacuate and contain all existing refrigerant. DO YOUR BEST to keep the system open for as little time as possible. The longer it's open, the more moisture can infiltrate. Replace ANY seals/O-rings that are disturbed with OEM replacements, rated for the application. Put a vacuum on the system for a while, and check to make sure that the system HOLDS vacuum. When recharging, keep in mind that you will have to adjust your desired high and low pressure DOWN a bit to cooperate with ambient temps.

Post by **abscate** » 10 Nov 2017, 09:14

Or you can evacuate and charge by mass - much easier.

I remember discussion over whether the DEFROST mode, which automatically turns on AC, overrides the temperature condition on the AC which disables compressor under 0C.

I don't remember the conclusion of course.

BeachWagon · Post by **BeachWagon** » 10 Nov 2017, 09:17

^Sounds like a reason to experiment!

Post by **wizechatmgr** » 10 Nov 2017, 10:36

abscate wrote: 10 Nov 2017, 09:14 Or you can evacuate and charge by mass - much easier.

I remember discussion over whether the DEFROST mode, which automatically turns on AC, overrides the temperature condition on the AC which disables compressor under 0C.

I don't remember the conclusion of course.

You should be able to verify this by the end of the weekend with the way it has been at home. =)

Post by **abscate** » 10 Nov 2017, 12:19

I could except I came to my senses and realized there is no way I am putting in a spare alternator and then doing the job again with a rebuilt. Pulled the old this morning. ordered new.

I spent 30 minutes of alternator tetris removing it from the 1999 - awful.