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Discussion Starter · #1 · (Edited)
Hello all, read this forum for years but never posted. If I do a panic slam on the brakes stop, nothing happens for about two seconds, then full braking is restored. Pedal goes to floor then about 1-2 seconds I feel the pedal kickback a little and truck starts stopping. The weird part is if I apply a little pressure, like enough to turn on the brake light, then slam it, it works as it should, immediate and hard braking. I have blead brakes, hawk pads and power slot rotors up front. Under normal conditions it works fine, it's just a scary few seconds if you slam em! Has anybody ever encountered this?
 

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Welcome to TheDieselStop

I'm not sure what your problem might be, but if you send a PM to member FMTRVT, he'll probably know exactly what you should do to fix it.

Normally, brake questions would be moved to the brakes tires and suspension forum, but since your hydroboost might be involved, I'm leaving it here.
 

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Could be the "power piston."
But that's just a guess. Lol

Sent from my SAMSUNG-SM-G935A using Tapatalk
 

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Discussion Starter · #4 ·
Thanks, I'll do that!
Not sure what a "power piston" is, but I'll look into that.
 

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Discussion Starter · #5 ·
Looks like I need 15 posts before I can PM. I'll work on that!
 

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If I do a panic slam on the brakes stop, nothing happens for about two seconds, then full braking is restored. Pedal goes to floor then about 1-2 seconds I feel the pedal kickback a little and truck starts stopping. The weird part is if I apply a little pressure, like enough to turn on the brake light, then slam it, it works as it should, immediate and hard braking. I have blead brakes, hawk pads and power slot rotors up front. Under normal conditions it works fine, it's just a scary few seconds if you slam em! Has anybody ever encountered this?
The condition is called kickback (as you described) and with hydro boost systems a little of bounce in the pedal is is normal but what you describe does not sound right. If the kickback pushes the pedal back a lot and braking is affected then you likely need to replace the booster. There is a technical service bulletin (TSB 07-11-10) for pedal kickback and or grabbing. The bulletin states that the fluid may be contaminated (or just in poor condition) and a system flush should be attempted before condemning the booster. That would be the Power Steering fluid...
 

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Discussion Starter · #7 ·
After investigating the problem a little further, when I slam on the brakes very quickly there are no power brakes for about 1-2 secs, but the truck does try to stop, just not very effectively. It seems to be a powerbrake issue, cuz I see/feel the truck try to stop, pedal goes to floor, and about 2 secs later pedal pressurizes and truck screeches to a stop. But still, if I apply them just slightly slower, they work effectively and immediately. No luck with a flush, so I ordered a new hydroboost.
 

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Discussion Starter · #9 ·
7.3L Tacklebox, do you think this is just a characteristic of this system, or we both have some other issue?
 

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7.3L Tacklebox, do you think this is just a characteristic of this system, or we both have some other issue?
There are tons of trucks (mine included) with the system that work just fine. So it's got to be some issue with your two trucks.

If there's air in the PS system it will cause kickback. I got that when I flushed my system and let the reservoir get a touch too low. Once the air was purged, everything was OK again. Use a mity-vac and pull a vacuum on the PS reservoir cap vent hole. That will help get the air purged out.
 

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Discussion Starter · #11 ·
Thanks klhansen, I will try that. I don't think there is any air in the system, but will give it a shot to rule it out! The problem isn't so much kickback, but a delay with the power brakes, and only if I really slam on the brakes, like to avoid an accident when someone pulls out in front of you. If I apply the brakes any slower than slamming them as quick as I can, it works just fine, and that is why I think I've had this problem for awhile with it going unnoticed. I have been slamming then brakes a lot lately, trying to diagnose, and if I rest my foot on the pedal then slam, it works fine, but if my foot comes from the accelerator to the brakes, that extra momentum is when it doesn't work correctly. The reman hydroboost showed up today, so hopefully that works.
 

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Discussion Starter · #12 ·
Problem fixed! New hydroboost solved the issue.
 
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I am having this same issue. Two months ago had to put a new running complete in at 121k miles. Now my braking issue started. What did the hydropump cost you. I just dropped $16k in this motor and another expense is gonna really hurt.
 

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Discussion Starter · #14 ·
ACDelco 14PB4347 $129.63 from carkart. I think their price went up to $163 now. But amazon has it with prime shipping for $152.08 - $20 rebate = $132.08. [ame]https://www.amazon.com/gp/aw/d/B0080DZ0K4/ref=mp_s_a_1_1?ie=UTF8&qid=1482336005&sr=8-1&pi=AC_SX236_SY340_QL65&keywords=ACDelco+14PB4347&dpPl=1&dpID=21YploVMa-L&ref=plSrch[/ame]

Good luck!
 

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I had the same issue. The 2011 6.7 I have did not have a hydro booster pump. I had my mechanic refill and flush the brake lines and got no change. Possible ABS or control module failure.
 
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