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Discussion Starter #1
2003 2WD tahoe w/ 4 wheel disc brakes vacuum boost.

Doing some brake repair for a supervisor. He thought his pads were bad, but it turns out he had other issues. Brakes would go to the floor no matter how hard you pushed the petal. The vehicle would brake, but it would only brake enough to stop. You couldn't get the brakes to try to lock up or get the ABS engaged. There wasn't enough line pressure. I replaced the master cylinder all fluid (junk was nasty) and the pads. Bled the system out. Line pressure is awesome. Now the brakes have a bottom and when you pump them, they actually lock, but the petal still feels spongy. It has way more travel than a 2003 yukon I compared to. The ABS engages now, and the vehicle braking preformance is 10x what it was before, but the pedal still travels more than I think it should and the bottom of the brakes is deeper than what feels right. What else should I look for. Does the porportioning valve need to be bled even though all the air is seemingly removed from the system? Anyone have any ideas? Is there a reducer?

I searched this forum for hours looking already. BTW there are way too many 3rd brake light threads.
 

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00Silverado
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2,104 Posts
Well all GM's are spongy to begin with. Did you replace the master cylinder with the correct size bore? You can get a bigger bore master and it will raise the pedal some. That valve can be bled if you want to make sure all the air is out but i dont imagine you will get much.
 

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Discussion Starter #3
I just went with a stock unit. The problem is I have no reference point, but I don't think the way this feels should by any means be considered normal.
 

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GMFS Member
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it sounds to me that there's still air on the system, check if theres bleeder on the ABS controller.
 

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Allison Specialist!
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675 Posts
more bleeding. sounds like got alot of air in there probaly after that master cylinder change.
 
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