Brake issue: occasional slight kick back and ABS feel in pedal

[Red Rider]

I am getting occasional slight kick back in brake pedal and what feels like the ABS kicking in for a second or so. It almost feels like pedal was rubbing against something. It happens occasionally when driving. I am overdue for brake fluid change. No trouble lights coming on.

Any idea what this could be?

2004 Tahoe z71.

 

[mattbta]

Hydro boost? Firestone told me mine was bad and couldn't continue diagnosing a steering issue without fixing it due to safety. I didn't have time to see if they were ******** me, but most likely were.

That's the symptom they said would happen when the hydro boost goes. I didn't recall ever noticing but had it replaced anyway.

 

[Red Rider]

I am not sure if I have hydro boost. Was that standard? Need to look at manual. I am going to bleed brakes tonight and see if that helps.

 

[rockola1971]

Hydroboost is an option typically for heavy duty brakes. Was like JB4 or 5 RPO code in the older trucks. My Yukon Denali has it. It looks like a funky manifold with brake lines coming out of it where a vacuum brake booster would normally sit behind the master cylinder on the firewall. Master cylinder is attached to it. I dont believe my Tahoes (2003) have it.

 

[Red Rider]

I do have that option. Looked through the specs.

 

[fiatdale]

Check your front speed sensors. Sometimes rust builds up on the knuckle which pushes the sensor out slightly, causing the ABS to kick on. Take the sensor out (one bolt) and clean the area of the knuckle it sits on.

 

[Red Rider]

cool thanks. I do notice that every time i drive the truck, what seems to be the front brakes feel like they have surface rust on them... similar to when a car/truck has been parked outside for a few weeks without driving and the rotors flash rust. I was told this could also be the dust shield rubbing a bit.

 

[retiredsparky]

Flushing the brake fluid does help sometimes. My fluid was old, and I had similar symptoms. New fluid did improve the pedal feel. The moisture in the old fluid can vaporize under certain braking conditions.

Also, hydroboost seems to have a different pedal feel, both my Ford F-250 and the Tahoe seem to have a similar pedal feel, and they both seem different from vacuum boost brakes.

 

[Red Rider]

After bleeding, i have not noticed it happening again, yet. I will keep an eye out. Definitely needed a bleed as it was getting dark. I had trouble bleeding out the ABS. I read that you needed to open bleeders and turn ignition to on to cycle ABS? At front driver side, it dribbled out. But at other wheels, nothing came out. I don't have the Tech 2 unfortunately.