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Discussion Starter #1
I have searched Google, C'Fans, and here for a cause/solution and I can't seem to figure this out. Basically what is happening is at red lights after i have been sitting about 30sec- 1min or so without putting more or less pressure on the brake pedal, the truck will start to inch forward ever so slowly. I usually have to put more pressure on the pedal and at really long lights it will do it 2 or three times. I know the rotors I have are warped, maybe the pad are bad? This happen to anyone else??? You guys are always so helpful. :355group:
 

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Are you loosing any brake fluid, or booster leak maybe, initally has enouph pressure to hold you stopped but looses pressure
 

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Are you loosing any brake fluid, or booster leak maybe, initally has enouph pressure to hold you stopped but looses pressure
^^ check every inch of your brake lines. I had the same problem...........I had a pin hole leak in my rear line.

NOTE: these truck loose a shit ton of fluid before the low brake fluid light/message comes on......the master cylinder was almost bone dry when the light finally came on.
 

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Sounds like a defective master cylinder. Fluid leaking past the seals.
 

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If the brake pedal gradually falls away while under foot pressure, there may be a brake fluid leak.

I would start by checking the brake fluid level in the master cylinder, and then visually inspect for external leaks. Give particular attention to all brake pipes and flexible hose connections to ensure that there are not any slight fluid leaks - even though the brake pedal may feel firm and hold steady. You want yo check the following: Master cylinder brake pipe fittings, all brake pipe connections, brake pipes, brake hoses and connections and the brake calipers and wheel cylinders.

Is there excessive pedal travel? The spec for the maximum brake pedal travel is 64mm (2.5") (measured with the ignition off, brake booster power assist depleted and the brakes cool)

I'm with BigR, it sounds like an internal brake system leak bad master cylinder.

http://www.355nation.net/forum/brakes/57707-help-changing-master-cylinder.html#post1726403
 

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Discussion Starter #6
I checked the brake fluid reservoir and it's filled to the top (a little over the "max" line). I am taking it in to my buddy's shop to get new rotors and possibly pads. I will check all the hoses and lines and see if I can spot anything when we have it up on the lift.
 

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Rotors and pads don't cause pedal creep. The system is hydraulic...once fluid pressure is applied there is no pressure release. If your pedal is creeping, the master cylinder is on the way out or you have vacuum problems. Another possibility is air in your brake system, but air is only introduced if you open the system, or if there is a hole in the system.

If it is a master cylinder, get it changed quickly. It's not too often you get a warning. The normal result (in my experience) is a master cylinder goes bad and you are made aware by the pedal going to the floor when you decide it's time to stop. Has happened to me on 2 vehicles.
 

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Discussion Starter #8 (Edited)
UPDATE: I checked all the connectors and hoses from front to back, no leaking fluid that I could see. Checked with my buddy that I bought my truck (back) from- he replaced the master cylinder 3 years ago. Checked the vacuum lines the one from the brake booster to the engine was connected but was loose on the engine end. I made sure it was nice and tight again then went on about a 45 min drive. Hit many stop lights and the problem seems to have gone away. Still going to get it checked cause I am taking it cause my rotors are warped. Thanks for all the help
 

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Even though he replaced the master cylinder 3 years ago it appears you have a defective master. Replace it and it should fix that problem.
 

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Discussion Starter #10
Even though he replaced the master cylinder 3 years ago it appears you have a defective master. Replace it and it should fix that problem.
I am probably going to do that anyway just to be sure. I don't like to mess around with brakes...
 

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I am probably going to do that anyway just to be sure. I don't like to mess around with brakes...
haha you wrote that as if it is optional. I don't think there are ways to test it. You might be okay for now if you think it's acting normally.

But if it were me, I'd probably take a detour to the parts shop if I experienced brake creep while stopped in the future. The first time it happened to me I was 17 or 18 probably in the parents car. Driving to pick up a pizza (I was allowed to borrow their car that day!) and the pedal went straight to the floor when I approached the intersection half way to my destination. Then it was okay then it wasn't. My dad test drove and it was fine.

A few years back in a different vehicle, A friend and I were dirt bike riding in the mountains. Half way down the mountain while driving home, pedal went to the floor. He didn't believe me until I pumped the brake pedal and we weren't being jolted around. I was happy to have a 4lo and 1st gear option that day.

Anyway, the master cylinder was the cure for both vehicles.

If you have never done a master cylinder before (and plan to do it at home) make sure you bench bleed it.
 

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Discussion Starter #12
I have a close family friend that's a Chevy mechanic. I called him and am dropping it off at his shop tomorrow. He's putting in a new master cylinder and machining my rotors for me.
 

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Discussion Starter #13
Got the truck back from the shop this afternoon. Replaced master cylinder, rotors, front pads and he serviced the drums as well. She can stop on a dime now and stay stopped. Thanks for all your help!!!
 

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I had the same problem with the truck creeping after having my foot on brake for 20-30 seconds. I replaced my master cylinder and it fixed the problem.
 
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