[Freejack7]

I hope someone can offer some advise on this issue.

I have a 2005 Z71 Crew Cab 4WD Colorado. I know I need to change out my front wheel bearings because I'm feeling a bit is vibration in my gas pedal and I pulled a wheel and I have movement in the hub. I also think I have one or both ABS sensors going out and it is causing an ABS fault. The bearing and sensors will be replaced in the next two weeks.

With this said there is something more with the brakes that has me concerned. This a random. Sometimes is happens shortly after I start to drive or sometimes in the middle of driving. Random... I hear what sounds like a pump priming under the dash by the pedals. When I press on the brake the pedal is firm when the noise is happening. Then the sounds stops and the brake goes mushy and I get a ABS fault light and sometimes a brake light. This is what I think..

1. Air in the brake lines?
2. Faulty ABS pump?
3. Faulty ABS module?


Has anyone experienced this pump issue?

The brakes work fine but are mushy I guess they are running on vacuum and the power assist is not working.


Thanks

 

[greco2003]

If you hold pressure on the peddel does it stay in place or slowly drop to the floor??

 

[cart7881]

:welcome to C'Fans

Can you get the truck scanned and post the ABS codes that are set/pending? The codes will give a clue regarding where the failure is occurring. Most AutoZone or Advance Auto parts stores will scan for no charge.

 

[DaleHutch]

I'll get the codes.

When the pump is making the noise it is very firm. No real movement to the floor. When the ABS Fault like appears it does move to the floor but not much.

Thanks

 

[jjgolfhacker]

I had a 2004 Z71 Colorado. The reason I got rid of it was due to a poorly designed Anti-lock braking system. The fault was with a raised bump on the hub bearing that sensed if the hub was spinning or not based on the magnet picking up the raised metal bump on the bearing of the hub. I read that a lot of these were failing and that the hubs basically had to be replaced. I ended up replacing both front hubs at about 60k miles at a cost of about $750 per hub. I am curious if they ever redesigned the anti lock brake sensors or if it's the same in the newer models. After that I sold my Colorado and bought a Kia Sorento. I used it every summer to launch jet skis and constant backing into brackish water cause the ABS sensors to fail at about 60k miles as well. I ended up replacing both rear hubs on it, but the hubs were only $50 a piece and I replaced both within a couple hours. I now own a 2021 Z71 Colorado and hope like hell they redesigned the ABS Sensors.

 

[jjgolfhacker]

I hope someone can offer some advise on this issue.

I have a 2005 Z71 Crew Cab 4WD Colorado. I know I need to change out my front wheel bearings because I'm feeling a bit is vibration in my gas pedal and I pulled a wheel and I have movement in the hub. I also think I have one or both ABS sensors going out and it is causing an ABS fault. The bearing and sensors will be replaced in the next two weeks.

With this said there is something more with the brakes that has me concerned. This a random. Sometimes is happens shortly after I start to drive or sometimes in the middle of driving. Random... I hear what sounds like a pump priming under the dash by the pedals. When I press on the brake the pedal is firm when the noise is happening. Then the sounds stops and the brake goes mushy and I get a ABS fault light and sometimes a brake light. This is what I think..

1. Air in the brake lines?
2. Faulty ABS pump?
3. Faulty ABS module?


Has anyone experienced this pump issue?

The brakes work fine but are mushy I guess they are running on vacuum and the power assist is not working.


Thanks

Sounds like my issue with my 2004 Z71, does it do it often while braking and turning simultaneously, like turn right or left on a street 90 degree turns?