Brake System Troubleshooting Help

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May 22, 2009 | 12:36 PM

Dx2ry

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Brake System Troubleshooting Help

I need help diagnosing the problem I am having with my brake system. I have a pulsing vibration when I stop, but I don't feel it in the brake pedal. So far I have completely changed out the front brake system (calipers, rotors, and pads) which was needed and I thought would fix the problem but it hasn't. I also checked out the rear and everything is still fine except I didn't check the runout on the rear.

My brake pedal is still feeling a little soft, so I am going to go back and bleed the brakes again and check all the vacuum connections. But other than those two things I am running out of ideas. Does anyone else have any ideas what might be going on?

Thanks

May 22, 2009 | 09:03 PM

bridge

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Year? Mileage? 2 or 4wd?

May 23, 2009 | 08:41 AM

Dx2ry

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2004 4x4 XLT with about 130k on it

May 23, 2009 | 10:38 AM

bridge

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Have you completely flushed the brake fluid? At 130K there's probably a alot of gunk in the lines/valves. I'd get a complete fluid flush.

May 29, 2009 | 04:47 PM

Dx2ry

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Now it is looking like something in the brake system is creating too much heat and boiling the brake fluid. The brakes are fine when the truck starts up, but as it warms up the brakes start vibrating and the pedal goes soft.

Anyone have any ideas why there might too much heat being generated now?

May 29, 2009 | 10:15 PM

Beechkid

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I would really look close at the calipers- 1 or more may be hanging up slightly during pedal release causing heat to generate and transfer to the fluid over time.

May 30, 2009 | 08:37 AM

Greg B

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I have heard that the emergency brake hanging up slightly can cause problems. Could also be an ABS issue. Since you mentioned soft pedal, I would investigate the emergengy brake system first. As Bridge said, old fluid can get condensation in it and need to be flushed to get any moisture out, but that doesn't happen all that often on vehicles driven daily, just on vehicles that are stored for lengthy periods of time. Soft pedal can also be a vacuum problem. Have you had the recall on the power brake booster vacuum line done yet if it is an 06?