Question about 2003 GMC Sonoma Extended Cab

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Noise under dash when applying brake pedal

I have a 2003 GMC Sonoma that I recently purchased. This last week, I have noticed a sort of thump sound that comes out from under the dash when I apply the brake pedal. The sound appears to be coming from up under the dash above the emergency brake area. I don't belive the sound is coming from the engine compartment but have no idea what brake coponenets are under the dash. Any thoughts?

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  • snlfinds Apr 20, 2009

    I generally don't use the parking brake. This sound happens everytime I apply the brakes while driving. It has gotten to be everytime now. It is a faint thunk sound that sounds like it is under the dash along the left side panel or directly above. There isn't any brake components there..correct?

  • snlfinds Apr 20, 2009

    Truck is an automatic. Noise is more of a clunk sound than click. If you are driving alone and apply the brakes, noise typically happens not upon initial pressure on pedal but as truck is slowing down. Almost like pedal has paritally traveled down before noise occurs. This is just a tough one to explain. Are there any specific components to look for under the dash in thsi area. I swear it almost sounds like some component or something is shifting up under the dash.

  • snlfinds Apr 20, 2009

    cadman000...thanks for your hlep with this. This morning, I may have figured something out. When I pull up tightly on the emergency brake, the noise doesn't happen when applying the brakes. Is it possible for some reaction to occur through the emergency brake cable up to the foot pedal when the back brakes are actuated? They are disc brakes all around.

  • Eric Heifetz
    Eric Heifetz May 11, 2010

    First my previous statement had NOTHING to do with parking brake. Not sure if you're driving an auto trans or standard,. Automatic transmissions have a shift interlock. Now here's the kicker. You say "while driving and applying brakes. COULD there be something in that area trying to keep on moving forward , when you are trying to stop, CLUNK ?

  • Eric Heifetz
    Eric Heifetz May 11, 2010

    sounds to me like the Park / Brake Interlock solenoid clicking to electrically allow you to shift out of Park. Some solenoids louder than others. I should qualify by asking . Do you hear this when you are moving upon brake apply, or can you be sitting still ?


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Well, now being 60, might be a bit of a challange for me , but if I had to..... anyway dress comfortably, push the front seat back as far as you can. Now lay on your back looking up UNDER the L/S of the dash where you hear the noise and LOOK. for something loose. Open the hood, look for something loose under the L/S of the windhield. Nothing to lose. Hope this helps

Posted on Apr 20, 2009

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