Air in ABS causing front brake vibration..........UPDATE BRAKES FIXED

[N Ga Rider]

Ive been working on the brakes of my 97 1500 2 wheel drive. Ive bled brakes and have gotten a pretty good pedal. But now have a vibration when braking that was not there before. I bought new rear brake drums and that helped, but I could still feel it in the front. It is so bad it shakes the dash and column when braking. So I replaced the front rotors with new ones. Vibration is still there. I have not been able to do a scan to purge the ABS (No Tech 2 Scanner) unit and was wondering if air in the ABS unit could make it vibrate. All rear shoes and front pads are new. I have a scanned the truck and have no codes or warning lights for the brakes/ABS.

 

[Erik the Awful]

Nope, you have something loose or misaligned. Check to make sure your rotors are seating flat against the hub.

 

[JOHNGAAA1]

Did you clean the hub surface, lube and or never seize the surface? If the rotor is not seated it will vibrate.

 

[sewlow]

Air in the brake system will cause a spongy/low pedal, but not vibrations.
You're description sounds like a bad rotor. Or both.
El-cheapo rotors?
I've had some of those so warped right outa the box they couldn't be turned to true them up. Off-shore junk.
Wheel bearings set properly? Loose ones will cause vibrations too.

 

[mr_josh]

The (Raybestos) drums that I put on my K2500 a couple of years ago were garbage from the factory. Crazy how out of round they were.

 

[Schurkey]

Go to a safe area--a mall parking lot on Sunday morning works well. No other traffic, decent pavement, no pedestrians, no cops, no surprises.

Drive 15--20 mph. Apply brakes. Feel vibration. Accelerate back to 15--20 mph. Apply park brake while pulling/holding the release handle so they don't lock on. Vibration gone? Problem is in the front brakes. Vibration still there? Problem is in the rear brakes.

'Course, you may have problems in both the front and the rear brakes.

Air in the ABS is unlikely to cause vibration.

 

[Nad_Yvalhosert]

Did you clean the hub surface, lube and or never seize the surface? If the rotor is not seated it will vibrate.

2wd rotors dont have separate hubs. They're 1 piece...

 

[Nad_Yvalhosert]

What about tire imbalance?

 

[N Ga Rider]

Truck runs true and straight down the highway. Original rotors were turned and were fine until master cylinder started leaking. Changed master the vibration started. It’s coming from right front. Steering wheel does not shake, brake pedal does niot pulsate. I’ve put in new rear drums and new rotors. Still had vibration. Took rotors back got 2 new ones and new brake pads. Still does it. I’m at a lose at what to do. Pedal is good and brakes well. Just the stupid vibration.

 

[Schurkey]

Steering wheel does not shake, brake pedal does niot pulsate.

Are you sure this is a brake problem?