Drum Brakes sticking when cold only.

Hydraulic issues check for sure, but also post #5 is an excellent point. The backing plates have flat pads on them where the shoe frames make contact with the backing plate. Sometimes when people replace the shoes, they don't know or forget to put some grease on those pads. I use a brake grease product that's ceramic based nade by Permatex and very high temperature and impervious to water, so it's not going to go anywhere.

https://www.amazon.com/dp/B0018PSASU/?tag=fabo03-20