2008 Sierra 1500 Rear Drums Replaced, Still Issues

OL_FAITHFUL · October 10, 2011

The rear drums started squealing on my Sierra so I took it to the dealership to have them replaced. Before having them replaced my emergency brake caught real high and there was a short distance between starting to catch and applies enough pressure for the truck not to roll, after being replaced it goes practically to the floor before tightening up and feels spongier for lack of a better word (there's a much longer distance between when I feel it start to catch and when it applies enough pressure for the truck not to roll in gear). I mentioned this to the service writer asking if they could tighten up the emerg brake, who brought the tech up that replaced the pads. The tech told me to "use the emerg brake and it will get tighter over time". He said there's an automatic ratcheting device in the drums that will tighten them up. It's been two days and I've used the emerg brake a good 30 times and no difference in pressure. I have to push it all the way to the floor for it to be able to hold keep the truck from moving in gear.

Sidebar, the brakes have a mild squeal to them at one particular point between not being applied and decent pressure, that pisses me off as well. So, my gut tells me this guy is full of it, but I thought I'd check here first. All I wanted was for my truck to be fixed right the first time.

OL_FAITHFUL · October 10, 2011

Went out and took a look. From what I can tell, when you apply the e-brake, only one pad moves out to press against the drum. The pad on the driver's side had wear in the middle of the pad about 1/2 the total distance of the pad. Pics of the passenger pad are uploaded below. Around 1/4 of the entire pad was making contact. In my novice opinion, that's not enough and should be adjusted. Opinions?

[img]http://i296.photobucket.com/albums/mm192/cwatwood/2011-10-09_21-18-35_206.jpg[/img]

[img]http://i296.photobucket.com/albums/mm192/cwatwood/2011-10-09_21-17-21_300.jpg[/img]

scirocco · October 10, 2011

I'm not a GM tech, but these drum brakes are very often adjusted via the "star" wheel you may find at the bottom/back of the drum. Turning it will lengthen (shorten) the screw/plug at the lower joint between the shoes.

There should be a slot where you can insert a screwdriver from the back of the brakes to move the adjuster. You want to open the shoes up so that the drum lightly catches/scrapes on them, and then back down just a tiny bit until they don't touch.

00Silverado4x4 · October 10, 2011

There is an automatic tensioner built into your brakes. It's silver thing just under the wheel cylinder & spring (on top), however using the brake isn't going to adjust the brakes. The adjusters are designed to adjust as you back up & then brake. You can also use a screwdriver through the opening on the inboard side of the wheel assembly. There should be a little rubber piece that keeps it covered that you pull out. On mine I just make it a point to (once in a while) back up & sharply apply brakes (5mph or so) to keep rears adjusted. I'd try one of those, then if no luck take it back to the repair center.

Stevens03 · October 10, 2011

As mentioned, you need to make several stops from a backwards movement to have the self adjusters... adjust. Just applying the e-brake won't do it.

OL_FAITHFUL · October 10, 2011

So, is the only adjustment the upper "automatic tensioner", or is there a lower one as well. From my pic, it looks like the uppers could use some extra tension, but looks to me like the area that needs the most adjustment is on the bottom of the pads.

Stevens03 · October 10, 2011

It's been a few years since I've been in there but I believe the only tensioner will be on the top or bottom. There isn't two places to adjust. You can assist manually if you like with a flat bladed screw driver. Just don't make them to tight that they drag. There use to be a hole in the back of the plate you could reach in with a screw driver to adjust them.

But... if you just go out and make say.. 5-6 backups in a parking lot braking somewhat hard, they should adjust themselves.

Debo511 · October 10, 2011

The only adjuster is on the top.

HawkScot · October 10, 2011

The adjustment is on the bottom, it should adjust automatic with the braking action when backing up. The top has the wheel cylinder and has no adjustment. Neither of these are the emergency brake per se. It is a separate cable that pulls the brake linkage so the brake lining moves against the drum. Make sure your regular brakes are adjusted correctly first, then you may need to adjust emergency brake cable.

00Silverado4x4 · October 10, 2011

[quote name='Hawkeye-08' post='1209065' date='Oct 10 2011, 05:10 PM']The adjustment is on the bottom, it should adjust automatic with the braking action when backing up. The top has the wheel cylinder and has no adjustment. Neither of these are the emergency brake per se. It is a separate cable that pulls the brake linkage so the brake lining moves against the drum. Make sure your regular brakes are adjusted correctly first, then you may need to adjust emergency brake cable.[/quote]

No disrespect but the adjuster is indeed on top, under the wheel cylinder & spring. I adjusted the OPs original picture showing where the adjuster is located.

HawkScot · October 10, 2011

No problem, I saw the linkages on the bottom and it appeared the same as older ones I have worked on... I see the star wheel now that you pointed it out. Apologies to earlier poster that also said it is on top.

Can I quit for today now? I learned something.

00Silverado4x4 · October 11, 2011

I remember when I was working on mine a couple a years ago & that stupid adjuster kept falling out of place just as I would get it all back together. Then I ended up getting a defective set of shoes so I got to do the whole mess all over again. The worst was the parking brake cable connection...

OL_FAITHFUL · October 14, 2011

I did the ol' back up @ 5-10 mph and stand on the brakes maneuver the other day with no avail. Still feels like I'm not getting much response from back there and the e-brake is not near as stiff as last Saturday when I took it in for service. In theory, the e-brake should be tighter with new, thicker pads. Guess I'll take it back to them this Sat. morning...

00Silverado4x4 · October 14, 2011

Did you try adjusting brakes from the outside? Also while it was apart did you take a good look at adjuster to make sure it can adjust itself? They will get full of crud/dust build up & possibly get hung up. When I did my brake job the adjusters weren't stuck but definitely weren't spinning freely either. After I cleaned them they adjusted just fine.