Had this happen plenty of times before with my old trusty 450c, but it appears that it also happens with my new 444c dual pack 
Whenever the temps drop below freezing, the check valve on the leader hose would freeze up, causing the compressor to run on and not fill the tank :mad:
In most cases, I can either tap the valve or pour some warm water over it to break free :o
I’d like to replace it with an SMC check valve, but not sure which one I should go with 
Do you think you would have the same problem with the new one? Have you looked into a heated line (power wire that is) like they make for water pipes to keep it from freezing, or thaw it out once you start the vehicle?
http://www.oemheaters.com/p-6111-12v-dc-heat-cable-9-wattsfoot.aspx
I’m not a sales person for these companies by any means, this was just a quick search on google… throw it on a rocker switch to bring the check valve above freezing then turn it off…
Just a thought…
Actually, that’s a damned good idea.
My dump valve on the bottom of my tank sticks when it gets below 35 degrees so I can’t hiss at people. I might give this a try.
Thanks!
-Kris
Someone suggested putting a small amount of anti-freeze in the tank but I have no idea if it works or not.
I actually ordered a 12v motorcycle hand grip warmer with the intention of wrapping it around the check valve, but from what I’ve read on the low rider forums, the ViAir check valve is known to freeze up and a good replacement from SMC is a common fix, so I’ll be going that route instead 
Drain valves usually have more moisture due to their position on the tank, so when the temps drop below freezing, I try not to use them for fear of sticking and leaving my tank empty :rolleyes:
As much as I use my dump valve on pedestrians, I don’t think the anti-freeze would make much of a difference :o