I thought I'd post this how-to since it seems like a common problem. It's not hard to do and makes the e brake perform the way it should. Hopefully it's clear, makes sense and that I didn't forget anything.
Many of us seem to have a problem with the park brake or e brake not holding the vehicle on a slope or having to push the pedal all the way to the floor to get a half decent hold. Another symptom of the brake needing adjustment is that the transmission clunks excessively when shifting from park while on a slope.
Our e brake shoes use the inside of the rear disc brake hat as the braking surface. You MUST remove both the rear discs in order to properly assess and adjust the brakes. I won't cover this here since there are other threads that already do that. Just remember to take the park brake off or you'll never get the disc off.
Inspect the inside of the hat to see if there is excessive wear and the shoes. My shoes were actually ok but the inside of the disc was pretty worn. There was a noticeable groove where the shoes meet the inside surface. I was installing new discs so this wasn't an issue. You'll need new discs if there is too much wear and/or new shoes. This write up is only relevant to the adjustment process.
There will probably be a lot of brake dust so you should use compressed air and then brake cleaner to tidy things up.
You will be adjusting one side at a time.
Steps for adjustment:
1. Make sure the e brake is off.
2. Look on the underside behind the wheel hub and you will see a small gear (red circle) that is partly obscured by the self adjustment spring. Use a flat head screw driver to turn the gear. I can't remember which way but I think you turn it towards the outside and up(does that make sense?) in any case you want to turn it in the direction that expands the thread which will move the shoes outward. In my case I turned it 2 full revolutions to start.
Looking up from bottom of hub assembly between the wheel hub and brake shield.
3. Mount the disc back onto the hub. If the disc slides right on you may need to adjust the gear more as the shoes are not making contact with the inside hat. If the disc does not go on at all then back off the gear as the shoes are obstructing the disc. DO NOT FORCE THE DISC ON!! It should NOT be a snug fit and you may not get the disc off again if it is too snug! Make the necessary adjustment to the gear until the disc goes onto the hub easily but with little side to side movement. (I had to file down the top edges of each brake shoe (red rectangle in above picture) just a bit as it was binding at that point. You may not have this issue but keep it in mind if your having problems)
4. Now, with the disc on, press and release your park brake a 2-3 times. You do this for 2 reasons:
A. To center/align the shoes and disc.
B. To set a comfortable pedal height.
If the pedal goes down too much, you need to adjust the gear some more. Too little and you need to back the gear off. I adjusted mine until I could push the pedal about half way without much effort and the disc was held in place. Each time you make an adjustment you need to pump the pedal a few times to repeat the centering and check the pedal height.
Once you find a comfortable pedal height, remove the disc and repeat the process on the other side. You want to try to adjust the pedal height about the same for each side so that the shoes are biting equally. After both sides are adjusted re-install both discs and double check the pedal height with a few cycles one last time. That's it...you're done.
Test drive to make sure everything sounds ok and that there is no rubbing or grinding. If you installed new pads and/or discs you'll need to bed them in. I drove slowly for a couple hundred yards with the e brake on slightly, release and drive to let them cool.
Applying my e brake holds the truck in place without any slipping. I don't even have to do the shift N, press e brake, release brake pedal, shift to P routine anymore, although this is habit now. I do notice that I probably could apply the e brake pedal closer to the floor if I wanted to but I think by doing that it might require you to adjust it more often and in any case it's not needed, even on the steepest slopes.
I hope this helps those of you that want to try it.