New Guy Please Help Diagnose

chips-ahoy · July 22, 2016

Hello,

I have a few issues I would like help diagnosing.

My truck - 2006 GMC Sierra 1500 (Non HD) Z71 4x4, 5.3L SLT - Bose Audio...heated Seats...All power everything...On-Start

#1- Brake issue

Symptoms - 1st push of the break pedal has little to no resistance on the first 3/4's of travel. Immediate follow up pumps of the break pedal do increase the resistance and improve braking ability slightly. Seems like air in the lines kinda? There is plenty of brake fluid in the reservoir. The truck is also throwing ABS wheel speed sensor codes. So i feel like there may be more than one issue possibly. The back breaks are drum style.

Someone suggested that the first half of brake pedal travel usealy engages the rear brake system. I plan to replace the ABS sensors, but other than that where do I start? Also, right about the same time this issue presented it self I noticed my parking brake would no longer engage..maybe that is related?

#2 - Electrical Feed back noise through the audio system.

Symptoms - This issue is intermittent..but while playing music sometimes a high pitch noise comes through my speakers and its intensity corresponds with my engine rpms. The intensity of the noise is not affected by adjusting the volume other than completely turning it down. Bumps in the road cause this issue to come and go. I have no idea where to start with this one...some many wires!

#3 - Dimer knob adjustment shorting out

Symptoms - The knob that controls the dimming of dash/gages lighting is temperamental...I figure i just have to replace the module..but I am listing this is case anyone thinks it may correspond with issue #2. When it is acting up, if I smack it or adjust it...sometimes it seems to affect the high pitched noise..but since it is an impedance style control that is probably the only reason I hear a difference....I am assuming. The two issue can and do occur separately as well.

Thank to anyone who reads all this and has any advice...

NARDA1 · July 23, 2016

I had the same brake issue on my truck, it would come and go sporadically. Never really did get it figured out. Just had the front pads and rotors replaced the other day (they were almost worn out) the problem is gone, nice firm pedal.

silveradosid · July 23, 2016

I found on my 2006 that the rear brakes would never adjust automatically, and I would get a lot of petal travel. I would manually adjust the rears every 6 months and that would bring the pedal back up