When I cover bottom valve cap and press valve, valve comes back slowly. What is wrong

Discussion in 'Trumpet Discussion' started by jp554731, Nov 21, 2014.

  1. Pinstriper

    Pinstriper Mezzo Forte User

    700
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    Nov 26, 2013
    Portlandia
    Re: When I cover bottom valve cap and press valve, valve comes back slowly. What is w

    A fairly quick DIY fix would be to scrub each piston for about 5 minutes each with 200 grit emery cloth. If done properly, each piston should rebound quickly even with the bottom cap sealed. A bastard file would be even quicker.

    The horn will also pretty much sound like a vivuzeala, or whatever it is they are called.
     
  2. Dale Proctor

    Dale Proctor Utimate User

    8,220
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    Jul 20, 2006
    Heart of Dixie
    Re: When I cover bottom valve cap and press valve, valve comes back slowly. What is w

    The piston should have a hole in the bottom and a smaller one somewhere on the top, located so the cork/felt doesn't cover it. I'm not sure why this passageway is there, since the bottom caps are vented and the top caps have clearance between the cap and the stem. Air does move through it when the valves are used, though, and your valve action will be a bit better if it isn't obstructed. An indicator of one that is obstructed or is in the process of clogging is a whistling sound when the valve is moved rapidly. Usually, cleaning and running something like a thin wire through the valve body will cure the tweets. I had an old cornet that continued whistling (on one valve) after a thorough cleaning, and was finally silenced by slightly enlarging the hole in the bottom of the piston.
     
  3. mchs3d

    mchs3d Mezzo Forte User

    988
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    Sep 30, 2005
    Provo, UT
    Re: When I cover bottom valve cap and press valve, valve comes back slowly. What is w

    200 grit? Try 20.
     
  4. rowuk

    rowuk Moderator Staff Member

    Age:
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    16,616
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    Jun 18, 2006
    Germany
    Re: When I cover bottom valve cap and press valve, valve comes back slowly. What is w

    Please don't try it at all.
     

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