[hatzie]

The drum brake adjusters will not work without the parking brake lever on the shoe.

For the people that say the cables freeze up. I have never had parking brakes freeze up and stop working when I was driving a vehicle at least once every month or so. Exercise the parking brake often. Use it when you park the vehicle. Even automagic transmission vehicles. That's what it's for.
I grew up driving manual transmission vehicles. It's just plain unsafe to leave them in gear unattended. I've had water run into the fuse panel on vehicles and activate the starter motor. My 75 Scirocco high school beater lurching into the back of Moms' new Impala crunching the trunk lid and back panel & smashing out her taillights in the middle of the night during a thunderstorm cured me of leaving vehicles in gear for parking. If I'd set it in reverse, as I often did, it would've lurched down the driveway, across a main road, and over the cliff into the river if it didn't get hung up in the brush or cause an accident on the road. Mom and my stepdad were more than a little perturbed. One of those things that I'll never forget even 40 years later but I bet they don't remember at all.

The added benefit of exercising it is the parking brake mechanism spins the star wheels on the automatic adjusters so you don't have to tweak them as often to get decent performance from your drum brakes. Properly adjusted rear drums will work quite well. I'd rather have front discs but properly working rear drums work just fine.

Cables are cheap and easy to replace. Illustrations showing routing and part numbers are in the GM parts books.