Air dryer safety valve popping off when cold

Hey y'all, I've researched as much as I could and I'm still lost. I have a Bendix AD-IS in this Pro Star I just bought- still working out the bugs Knight didn't. O bought the truck a couple months ago when it was warm. First time it dropped into the low 40's, the air pressure would build to about 140 psi or so on the gauges, and the safety valve would pop, air pressure would drop to about 70 psi, and build back up.

Last night, I hunkered down under 2 comforters and shut her down as it hit 16° in upstate NY. I started the truck this morning, and it must've popped off about a good 8-10 times until it finally warmed up enough and purged at 120 psi like it's supposed to.

Any idea why the cold is causing the air drier to build up too much pressure?

 

Thanks everyone for the responses. I think I might just replace the whole thing with an aftermarket unit from Ebay or Amazon for under $150. After 500,000 miles it couldn't hurt.

 

This is an ADIS model, nothing it's ever easy for me. I did replace the desiccant filter and the darn thing is buzzing away even with 185° water temp, oil at 220°, but it's 18° outside. I need to check the heater, because I think that's the issue. But these stupid internationals have the worst fuse box set up ever! The diagram is clearly labeled, but does not at all reflect what the heck is actually installed in the truck.