Jacob Ticking?

Discussion in 'Heavy Duty Diesel Truck Mechanics Forum' started by Wrench_Shaker, May 22, 2017.

  1. Wrench_Shaker

    Wrench_Shaker Bobtail Member

    31
    4
    Feb 4, 2017
    0
    I have N14 with a light tick that developes after 1 hrs worth of using it. Its seems to be on the back box and goes away for 10 second after using the Jacob Brakes. Then slowly comes back. It is hard to get it ticking bob tailing and likes to fade out when idling. It like to come back if you rev it a half dozen times. Sounds like a valve lash but they are perfect. I was wondering if a Jacob can leak out or sag and caused a ticking sound.


    Or any other places to check. I had look at manifold for leaking....
     
  2. Truckers Report Jobs

    Trucking Jobs in 30 seconds

    Every month 400 people find a job with the help of TruckersReport.

  3. ClineER

    ClineER Light Load Member

    229
    139
    Apr 27, 2016
    N.E. Oklahoma
    0
    I have seen a cat tick when the spring that holds the jake piston up broke. But after sitting a minute the piston dropped down and easily verifiable.
    Also check and make sure all the rockers are oiling good, had several m11 spin a cam bearing and only notice a tick in an injector but rockers has noticable less oil going to it.
    Have seen wornout 855 injectors do likewise, hook rocker arm and swing over and compress injector and see if it changes
     
    Last edited: May 22, 2017
    Wrench_Shaker Thanks this.
  4. Wrench_Shaker

    Wrench_Shaker Bobtail Member

    31
    4
    Feb 4, 2017
    0
    I'm think exhuast, injector or jacob because if jacobs use can dampened or cure for a 10 seconds....I was wonder if injector could do that. They are old injector with new springs is all. It's a really pain to get it to act up at the shop. I'll check the springs to make sure they are staying place. Thank you

    Compress the rocker spring is great idea. Thanks
     
  5. pup

    pup Light Load Member

    251
    255
    Dec 3, 2011
    n.h.
    0
    A broken flat spring on the master piston would certainly make the noise you're describing. They tick just like a valve with excessive lash. No need to remove the brake to inspect it. You can feel it or use a mirror to see if the piston is resting on the adjusting screw. I'd be careful with compressing the injector spring if it's a celect injector. During training when they first came out we were cautioned against doing that. Not sure if the pushrod could come out of its socket or not. Never tried it.
     
    Wrench_Shaker Thanks this.
  6. rmankid

    rmankid Bobtail Member

    7
    15
    Mar 21, 2016
    0
    j\Jeeze pup, you're all over the place. Good advise though.
     
  7. Superhauler

    Superhauler TEACHER OF MEN

    12,209
    100,723
    Jan 30, 2010
    keep stroking.
    0
    I had a Cummins long time ago that would develop a ticking bout every 4th month. On the back head. It would break a head bolt and start chirping or ticking as the head gasket would erode. I would carry a spare head bolt and would replace it when it started doing that. The deck of block was wore real bad.
     
  • Truckers Report Jobs

    Trucking Jobs in 30 seconds

    Every month 400 people find a job with the help of TruckersReport.