Bill, the brake adjusters really have nothing to do with how tight the emergency brake is.

If you back off the adjusters to loosen the cables, it may work, but it's not the correct way to do it.

There are three e-brake cables. Where the cable from the dash mounted e-brake control meets the two rear cables, there's an equalizer bar there that has an adjustable rod attached on it.

All three cables attach to the equalizer bar.

Tightning up the nut on the rod takes up the slack in the cables.

If the rear brake shoes were replaced, and someone forgot to re-adjust the cables, there's the problem.

I would not recommend using any lube anywhere inside the brake drums, because it could end on the brake shoes.

These trucks came from the factory with self adjusting brakes, which only work when the truck is backed up and the brake pedal applied.

Within a few short years, these adjusters become next to worthless because the self adjuster cables stretch.

More times than not, the cables snap, then the self adjuster cable guides bump around inside the drums, and may end up between the drums and the brake shoes, which when the brakes are applied, gouges the hell out of the drums.

NAPA used to sell a kit to replace those self adjusters.

The self adjusting system is the same thing as the cars used, but some of the parts are truck only.

btw: The OP has two threads on this topic. He asked what was the function of the tube that fits into the rear brake hose junction block. He thought it was some sort of bleeder.

I explained to him in the other thread that it's the rear axle vent, and it just passes thru the junction block and threads into the axle housing.