06 Sierra Brake Problems

kdagenais · February 16, 2010

Okay so I am losing my mind on this and here is the break down. I have a 06 GMC 3500 with 6.6 Duramax that can't get a brake pedal to stay up for the life of me. So far only things replaced where brake pads front & rear, Master cylinder, & hydro boost (Was leaking). No matter what I do after a day it gets air in the system again. Even had a GM tech bleed it cycling the ABS still no luck. Got new problem today while the pedal was still solid the left rear brake was getting hot like it is dragging. After awhile lost the pedal and that went away.

Just need somewhere to go from here and don't want to spend anymore money unless I know it is needed.

Thanks In Advance!

r1byker · February 16, 2010

I'm not a brake expert, but I think I'd tear that left rear brake caliper (or is it a drum?) apart and see what's going on with it. Something's hanging up in there and it sounds like you're going to have to do it anyways since it drags when the system is working. It might be the source of all your problems....or not.

It does remind me of a '72 Nova I had when one of the brakes were hanging up. It turns out that it was a leaking brake cylinder. I can't imagine it happening that soon on an '06 unless you're living in some harsh environment with lots of salt, etc.

r1byker · February 16, 2010

Maybe the master cylinder wasn't primed correctly?

kdagenais · February 17, 2010

Okay starting to think it is in the ABS valve somehow. Because you will hit the brake sometimes have nothing then the next time have a awsome pedal. Have bleed the master cylinder the way I always have and even pulled the lines of to verify it is pushing fluid as required and it is. Looked for leaks front to back and nothing which is leading me to the abs valve letting air in somehow and not sure how to test before just throwing parts at it. The rear caliper is working fine now and again wonder if this is a sympton of the abs valve. Have bleed many brakes before and never had this trouble before for they aren't that complicated which is obvious to me something is wrong just don't know where to go from here without spending a fortuane unnecassarily.

jblakeney · February 17, 2010

Okay so I am losing my mind on this and here is the break down. I have a 06 GMC 3500 with 6.6 Duramax that can't get a brake pedal to stay up for the life of me. So far only things replaced where brake pads front & rear, Master cylinder, & hydro boost (Was leaking). No matter what I do after a day it gets air in the system again. Even had a GM tech bleed it cycling the ABS still no luck. Got new problem today while the pedal was still solid the left rear brake was getting hot like it is dragging. After awhile lost the pedal and that went away.
Just need somewhere to go from here and don't want to spend anymore money unless I know it is needed.

Thanks In Advance!

Sounds like air in the ABS module by you loosing the pedal....... Edgewise... I believe you have disc brakes in the rear.... So check the hose for weak or hard spots squeeze down the entire length of the hose going to the caliper (feeling for hard or soft spots). It is possible you have a restriction in the hose. When you have a restriction in the hose it would give you a good pedal feel and then cause the brake to drag. I have seen hoses multiple times fail on the inside, creating a bubble on the inside. The brake fluid will go towards the caliper then, when you let off the brake it will not gravity feed back towards the master cylinder (thus causing a sticking caliper).

Jbo