Sluggish valve problem

Discussion in 'The Rehearsal Room' started by stevetrom, Dec 16, 2011.

  1. stevetrom

    stevetrom Well-Known Member

    I am playing on a Sovereign EEb bass and the valves are generally fine but occasionally the 3rd valve in particular is very slow to come back up.

    Any ideas ?
  2. GJG

    GJG Well-Known Member

    1) Clean it (No, I mean really clean the valves, pistons and casings and all, degreased and polished ... not just wiped over with a dirty rag)

    2) Re-oil ...

    3) If that doesn't help, it's worth taking the springs out and stretching them a bit. Or buy new springs; I believe you can get some super-dooper special valve springs from Steve Mead's online shop - don't know if they might help ...
  3. Bryan_sop

    Bryan_sop Active Member

    I know someone that uses double springs. A set of BBb springs and a set of Eb springs on them. One of the best players in my area actually and he never has any problems. Could be that they just need cleaning too. Washing up liquid and a soft nail-brush in luke-warm water.
  4. McQueens

    McQueens New Member

    If its only sticking occasionally, especially when warm then your valve has some high spots that require lapping down.
    Changing the springs or fitting stronger springs will only mask the underlying problem.
    Your valve should run freely without any springs.
    Best to take it to your local repair workshop.
  5. David Pegram

    David Pegram Member

    simple get back on Bass Trom
    Have a good christmas
  6. fsteers

    fsteers Member

    Have you checked the valve guides for burrs and cleaned the valve guide grooves?

    Not familiar with the valve guides on Sov basses, but if they're held in place by the valve stem like a Yamaha 822, where the valve stem tightens a washer that holds the plastic/metal guide), the guide can shift in the guide slot if the valve stem becomes even slightly loose, which causes the guide to bottom out and the valve to stick about half way down. If that happens, no amount of oil or cleaning will help. You need to loosen the stem (you may need to unscrew the stem completely) and reseat the guide in its proper place (there is a little plastic "nipple" that fits into a hole in the valve.) Be careful to seat the plastic guide properly, then push the it in so that the tab that fits into the slot is pushed in as far as possible. Retighten the stem, oil the piston, and reinsert it into the casing.
  7. talant

    talant Member

    Hey Rick what if that doesnt fix the problem? what do you do then lap again or give up? i had a simalar problem with a strad cornet!
  8. McQueens

    McQueens New Member

    The problem WILL be fixed and will not need repeating.
    Once the valve has been hand lapped within the valve casing, it is then polished with a Sisal compound to remove the surface scratches.
    If the valve is hand lapped correctly by a craftsman, this procedure is failsafe....I have done thousands!!
    Be sure to take it to a fully time served professional repairer!!
  9. mclaugh

    mclaugh Member

    Valve lapping removes metal from both the piston and the casing, and as such, is non-reversible.That's a fairly extreme course of action, especially as a first attempt at a solution, when it could be something as simple as a worn or deformed valve guide.
  10. McQueens

    McQueens New Member

    Obviously if the valves are not sticking with the valve guide removed, then the problem lies within the guide itself.
    Hand lapping is far from extreme, I have over 40 years in Brass Band Repair Business.
    Valves that are lapped in using the correct grade of compound, only the high spots within the valve block and the valve will be removed.
    No metal removeal whatsoever. Perfectly safe.
  11. TrumpetTom

    TrumpetTom Member

    It could be that your not pressing it down straight and you need to change your hand postion slightly
  12. stevetrom

    stevetrom Well-Known Member

    Cleaned and re-oiled, i'll see how it goes tonight
  13. MoominDave

    MoominDave Well-Known Member

    Just checking Steve - you do know there's no rehearsal tonight? Nothing until Thursday 5th January.

    I've never had any trouble with a sticky 3rd valve on that bass (have borrowed it for orchestral gigs quite regularly) - so I'd tend to suspect that you're putting it down slightly skew.
  14. mclaugh

    mclaugh Member

    If lapping does NOT metal from the high spots, what, pray tell, DOES it remove?
  15. talant

    talant Member

    Rick you lapped my strad cornet valves twice and they still stuck remember? Perhaps there is another reason for the sticking valve, such as damage to the slides etc. Lapping is none reversable what if high spots are not the problem?
  16. jasonG

    jasonG New Member

    Dont press it.... Simple!
  17. Aussie Tuba

    Aussie Tuba Member

    I have to ask the same question. surely the high spots are metal and lapping will remove metal as will the polishing. I agree that is the most likley way to fix the problem. But don't lie to the customer. Lapping removes un wanted metal, just explain it better.
  18. talant

    talant Member

    Aussie Tuba... what if after lapping it still sticks? sticking valve = dirt, damage or distortion. lapping should never be needed. the tollerance in the valves increases over time therefore why take more metal off? get expert advice first!!!!!
  19. Aussie Tuba

    Aussie Tuba Member

    my reply was to a repairer on this site saying lapping doese not remove metal. of course you need advice from a repairr. cleaning will get rid of most things in a valve that makes it stick. The OP hasn't mentioned if this is a new or old instrument. if OLD it would moslikley need a clean. if NEW then lapping may be the option. When manufactored all valves are lapped to fit and with some new instruments that may need completing. I get my own tuba serviced on a regular basis and my valves never need lapping, just a clean and oil. my euphonium on the other hand had worn valves. They were replated over size and machined and then lapped to fit.
  20. GordonH

    GordonH Member

    If valves are sticking its often down to them being operated at an odd angle and wearing in oddly over a long period of time. Lapping them in will deal with some of that. It usually only removes material from the casing side and then its often mainly dirt or mineral deposits being removed rather than real metal. Either way its normally easily fixed by a repair person. If its an old tuba consider an ultrasound clean and a general service first as that should knock off any mineral deposits.

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