Yellow knob not staying pushed in

Discussion in 'Ask An Owner Operator' started by draya93, Sep 7, 2024.

  1. draya93

    draya93 Bobtail Member

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    Hey guys. Having an issue with my truck. Yellow dash valve won’t stay in or go in. Truck is bobtail and starting leaking thru the red gladhand if I leave my palm pushed in and if I let go,it won’t stay in. Gonna tackle it tomorrow but anyone have something similar happen? Or what to check for?
     
  2. Long FLD

    Long FLD Road Train Member

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    Tractor protection valve? That’s my only guess.
     
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  3. SomeCanadian

    SomeCanadian Light Load Member

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    I don’t recommend it but as a stop gap to replacement, on some models of brake release valves it is possible to replace a worn o-ring to solve the not staying in problem. (Was a former employer’s solution to hitting a bump and the brake setting while driving)
     
  4. MTMAUS

    MTMAUS Light Load Member

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    Did you get this sorted? My yellow knobe won't push in due to have air pressure behind it.

    It's quite hard to push in and won't stay pushed in because of high air pressure behind it, wondering if it's the yellow brake valve, or if something else could be back feeding into the system
     
  5. draya93

    draya93 Bobtail Member

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    Yes, it was the dash valves. Bought a new one at fleet pride and fixed my issue.
     
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  6. Troy_

    Troy_ Road Train Member

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    Great to see a thread starter respond. So many threads like this go unanswered after a length of time, frustrating when searching for an issue, finding several threads on the topic without answer or resolution. Kudos to you sir.
     
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  7. MTMAUS

    MTMAUS Light Load Member

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    Are all Mv3 valve ls the same? They are aren't they?