first you have to make sure you have taken up the slack at the rear drums as there is not much tolerance in the cable's for slack. the rear brake adjusters are the only adjustments available. on older vehicles that i remember the E cable had some form of turnbuckles or slack adjuster to adjust for cable stretch. maybe a universal e brake adjuster kit might fit the bill?

 

Thanks for the help, actually there are no adjusters on the a 2005 only cable-couplers. Also it makes no difference taking up the slack, all that happens is the rear brakes come on.

To all intents it looks like the drum in the pedal mechanism (and hence cable) doesn't move until the pedal is pressed by about 5 degrees, like it needs winding-up or something.

I may have to buy a spare mechanism just to work out how it operates, so difficult to see.

 

since you mention you might be missing part of your manuel maybe this link has what you are missing
https://3ruk.ru/vehicles/kig/quc/caree

 

Thanks 🙏 to all who helped with the sticking" Parking Brake Pedal Assembly", results as follows:-

1. The mild-steel mechanism was corroded preventing the plastic tensioner drum from returning, no amount of lube helped.
2. As there are several pressed-in rivets so trying to repair it was too difficult and risky, thus it was replaced. Many thanks to @ejsmall for his post and confirmed "ACDelco #20803236 is a legit supersede for ACDelco #15952290" 👍
3. The new mech comes complete with brake cable, pull-release (discarded) and a disposable locking-pin already in place.
4. There are 3-off 10mm A/F nuts holding the unit, however the bottom stud is shared with the IP Relay Block which has one additional nut, the block need to be released and pushed aside. Access is very fiddley and there is a large cable harness obscuring the top-rear nut, a large zip-tie helped pull the harness forward to gain access.
5. Replacing the top brake cable is quite easy except for removing it from the brake-cable "joiner" underneath the vehicle, a small portable vice was used to hold the joiner whilst the cable -end was tapped-out.
6. Once fitted and the brake cables joined the disposable pin can be pulled-out.
7. As mentioned there was no issue with the rear-brake cables sticking, the first few degrees of pedal movement doesn't engage them and it was this action that failed to return.

The manual's description of "Automatic Adjuster" suggests there's some adjustment, I don't believe there is, all the pin (tool) does is hold-back the plastic tensioner to provide some slack whilst cable are changed, there are no cable adjustments on a 2005, only the drums as @bronxteck indicated.

The new mech also showed faint signs of corrosion, suggesting this could be a common problem, even it's return force was not that strong so it wouldn't take much to hold it back.

Thanks again ✔️✔️✔️

 

Glad that was helpful @oceanbrave . I have replaced 100% of the emergency brake system and still cannot get it to adjust correctly. Either too tight and wont fully release, or too loose and wont hold the truck on a hill, let alone with a trailer. In theory the drum ratchet should adjust up over time, but hasnt yet. Its one of the very last things on my problem list after my huge frame off mechanical restoration. At this point the truck is a car meet queen so not a big problem. But as a compulsive perfectionist it drives me nuts.

 

@ejsmall
Sympathize, I had similar issues.

Following the service manual procedure (0.026" clearance) with new rotors, shoes, adjusters, springs etc it seemed hard to be precise. Instead of Clearance Gauge J 21177-A I used large digital calipers which did the same job effectively.

Even when convinced everything was adjusted correctly one side was binding, so had to back-off the adjuster which seems to nullify the whole set-up process.

It's probably my lack of experience with Hummer brakes, however I will add the cables and footbrake mechanism played no part in my case.

 

really bad oversite from GM to not have an adjustment window on either the front of the rotor like some have or a hole in the backing plate with a rubber plug like others have.