3406b missing allen screws from pump??

Discussion in 'Trucks [ Eighteen Wheelers ]' started by seth Pivarnik, Nov 7, 2015.

  1. seth Pivarnik

    seth Pivarnik Light Load Member

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    Nov 7, 2015
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    I have a 3406b cat sn# 7fb36124 pump sn# 7w3906. This truck is new to me and after running it for a while I thought I would try turning it up a little for more power on the hills. When I pulled the cover off itblooks like the outside Allen screw and lock nut are gone. So kinda at a loss of what to do now. The truck doesnt get hot only 700egts post turbo. So I thought I might have been stock but iii doesn't seem like it. Any help on what to do would be great thanks in advance
     

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  3. Pool6710

    Pool6710 Medium Load Member

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    Minnesnowta
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    A upgraded/new pump?
     
  4. seth Pivarnik

    seth Pivarnik Light Load Member

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    Not that I know of it looks like the original. The motor is in a 1985 Peterbilt 359. The previous own told me the motor had an inframe 2 yrs ago and that tge motor was a 400hp 3406b but my cat dealer said it left the factor as a 310hp model. So maybe the p.o. pulled the screw for more hp on the rebuild? But I still have the screw closest to the block what do I do with that one? I'm just looking for a little more power for the hills. It only makes 15lbs of boost and post turbo egts are 700 degrees max with the pedal to the floor and grossing 78k.
     
  5. seth Pivarnik

    seth Pivarnik Light Load Member

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    Nov 7, 2015
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  6. Pool6710

    Pool6710 Medium Load Member

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    Aug 10, 2014
    Minnesnowta
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  7. Cory wood

    Cory wood Medium Load Member

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    Nov 7, 2015
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    With no screws in the pump it should make piles of smoke and way more boost than that. Check your afrc diaphragm for a hole
     
  8. seth Pivarnik

    seth Pivarnik Light Load Member

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    Nov 7, 2015
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    If it had a hole wouldn't I still get all the the full just not the boost to clean it up? I would think that my egts would be way higher than 700? Also how to I check the diaphragm? I've pulled off the first cover to bottom out the little screw. Would I just take more off or what?
     
  9. Cory wood

    Cory wood Medium Load Member

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    If there is a hole the boost you are getting will not push the rod forward which allows the pump to deliver more fuel. Yes just take the other two bolts off and there's three o rings and a couple springs and the diaphragm.
     
    seth Pivarnik Thanks this.
  10. Prom Night Dumpster Baby

    Prom Night Dumpster Baby Medium Load Member

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    Jan 12, 2012
    Bug Tussle, TN
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    If you only have one the one fuel screw take that and move it to the outside hole so you have a torque rise screw. hold rack all the way open and screw in torque until it hits something then just another thread and tighten lock nut. You want to push in on the torque screw and feel just a fingernail's thickness of spring play.

    But you might as well just buy another screw and nut so you have them both.
     
    Old school 362 and seth Pivarnik Thank this.
  11. seth Pivarnik

    seth Pivarnik Light Load Member

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    Nov 7, 2015
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    Okay thanks, I'll check it when I get home from running this week. Is it hard to replace o read that it's best to have a a cat tech replace it but I don't have anyone that's familiar with these b models
     
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