Gmt 800 Back Brakes Locking Up?

[uchi]

hey guys, real weird thing started to happen during these cold winter months. i noticed that when i come to a stop if i give the brakes just a little more of a squeeze i can feel the ass end lock up while the front is still rolling. this is in snow mind you. now i know my front brakes were grabbing harder than the rear when i bought the truck in october by testing the locker with a big smokey burnout, and now the backs are grabbing first. what could be the cause of this and how would i go about fixing it? would a simple cleaning of the shoes and drums be enough? truck is an 06 crew cab sierra z71

[WJR]

Removing the drums and ruffing up the shoes will help for a while but every truck with rear drums I've owned have had this happen mainly when it's cold and damp in the winter.

[00Silverado4x4]

I did a full brake repalcement on my '06 about a year ago & all was great...at first. Then I had the same problem, rear end kept locking up. I couldn't tell if it was the front or the rear at first. I looked over the front, all good. Then when I went to the rears I found that all four shoes had developed a ripple across the entire braking surface. I replaced the rears again with a new set & haven't had the problem since. Well except for the typical brake drum dust squeak from time to time.

Long story short (too late) look at your shoes. I'd bet there is your problem since we have the same truck. Hope this helps.

[The John]

When you come to a stop, can you feel something grab? And when you press the pedal it won't move and feels like something's holding you from moving and then it just lets go?

[uchi]

i get an occasional clunk when i start form a stop, gm claims its just a combination of slack in the entire driveline that makes it feel worse than it is, personally i think those gm counter jockeys are retarded and should stick to licking short bus windows. occasionally when i move from a stand still it feels like a thud coming from the back, its not always there but seems like 3 out of 5 times i feel it. as for the brake grab, i noticed today while coming to a stop if i was moving slow i could press the pedal down just a little more and feel the back end lock up and the front kept rolling still, if i pressed a little harder the front locks and the abs kick on, but regardless the back tires are grabbing first. i actually noticed this the other week when the roads were dry, im trying to give the wife an excuse for me to buy new tires so ill randomly do a little burnout here and there, and lately she hasnt been able to do one, although if i just mash the gas from a stop she'll happily lay rubber so i know the truck isnt low on power.

 

ill yank the drums off maybe tomorrow, ive got a short day at work and my buddy owns a garage so if he has a hoist open ill pull the drums off and give everything a scuffing and cleaning. thanks for the help guys, i was hoping it was just something common that was a simple fix and not an issue with the truck itself that would require another visit to the dealer

[Mckenzie]

I know the feeling, when we got our snow down here, my brakes would seize up whenever i hit the brakes. It dam near got me in two or three accidents to.

[uchi]

im glad its not just me, although in this day and age with technology where it is youd imagine that a company as big as gm would find a way to keep drum brakes from locking up when the weather gets cold

I know the feeling, when we got our snow down here, my brakes would seize up whenever i hit the brakes. It dam near got me in two or three accidents to.