Brakes still vibrate?

[Dmac909]

1997 C1500 Standard Cab: I am rebuilding this truck after it set for years. I rebuilt the whole front-end (Moog) accept for the rotors and brakes. (They looked good) After the alignment the truck shuttered when breaking so I changed out the rotors and brakes with ACDELCO gold parts. It still shakes when stopping. Not as bad as before the rebuild but still unacceptable. Could it be the calipers?

 

[Erik the Awful]

Have you checked the rear brakes?

 

[HotWheelsBurban]

And did you lube the caliper sliding surfaces?

 

[Dmac909]

The rear brakes are all new also. I also lubbed the calipers.
I would call it a Shudder and seems worse the more I drive it. If I ease (Really ease) on the brake it doesn't do it. I am Puzzled

 

[Nad_Yvalhosert]

Try driving slowly in a parking lot, and use the parking brake to slow down. If it pulsates, it's likely NOT the front.
Put the drums on a brake lathe and check for out of round. I've seen TONS of warped white box drums over the years.
You could also check the run out on the front rotors with a magnetic base dial indicator.

 

[Dmac909]

I believe your right. I am having the new acdelco drums turned tomorrow. I will update as soon as I know. Thanks a TON!

 

[GoToGuy]

If you have new drums why are you turn them before checking concentricy. Shuttered- closing shutters. A shudder as in shaking action. As you apply braking at speed it starts as you slow does the action still sharp or does it feel not as sharp movements? Are those rotors fixed or slipon over hub? Some foreign matter under rotor back or not installed flat hub will simulate a warped rotor. A few thousanths out at 70 mph might feel like machine gun underfoot. Then at 20-30 feel like wah....wah...wah slow up and down. When the shaking is have turned the wheel a few, not alot, just a few degrees left or right? And this shaking is coming through the brake pedal feel? The reason i ask is customers came through did alot of there own work, and yet missed something that only showed up when suspension was functioned as designed. One being under some braking thats when an oh crap showed up. Not everyone, just sometimes. Cover all your bases. Good luck.

 

[Dmac909]

It was the brake drums. I thought I bought ACdelco but they are Brake Best Select from O'Reilly's. The mechanic said the are warped like crazy and see if I can get my money back. So......I came home and sanded the old hubs (rust...because I threw them out) and it is perfect now. Thank all of you for trouble shooting this. GREAT COMMUNITY!