valve section (lack of) compression

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dbwhitaker
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valve section (lack of) compression

Post by dbwhitaker »

Should a valve section be relatively air tight? If I insert the F tuning slide on my TR-180 without opening the rotor I feel very little resistance and I can hear air escaping for about 2 or 3 seconds. I can't do this on my 50B2 -- both valve sections put up a fight and hold pressure.
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ithinknot
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Re: valve section (lack of) compression

Post by ithinknot »

dbwhitaker wrote: Sat Feb 26, 2022 8:57 am Should a valve section be relatively air tight?
Yes.

Assuming everything's lubricated properly, the rotor might be absolutely fine, but misaligned and thus not sealing. Or it's worn and leaking... or there's a broken or never-soldered joint somewhere, or a crack, or...
Jimkinkella
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Re: valve section (lack of) compression

Post by Jimkinkella »

ithinknot wrote: Sat Feb 26, 2022 9:28 am
dbwhitaker wrote: Sat Feb 26, 2022 8:57 am Should a valve section be relatively air tight?
Yes.

Assuming everything's lubricated properly, the rotor might be absolutely fine, but misaligned and thus not sealing. Or it's worn and leaking... or there's a broken or never-soldered joint somewhere, or a crack, or...
Or misaligned slide tubing, or out of round slide tubing...
Estraven
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Re: valve section (lack of) compression

Post by Estraven »

Hmmm… I have a valve that has something like .01” gap between the rotor and the shell. Its so bad I can’t write it off to just wear, it has to be bad quality control at time of manufacture.

I cannot get this horn to “slot” notes to save my soul. Could the bad rotor be the reason?
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Burgerbob
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Re: valve section (lack of) compression

Post by Burgerbob »

Estraven wrote: Mon Feb 28, 2022 8:58 am Hmmm… I have a valve that has something like .01” gap between the rotor and the shell. Its so bad I can’t write it off to just wear, it has to be bad quality control at time of manufacture.

I cannot get this horn to “slot” notes to save my soul. Could the bad rotor be the reason?
I doubt it would be anything else.
Aidan Ritchie, LA area player and teacher
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Doug Elliott
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Re: valve section (lack of) compression

Post by Doug Elliott »

20w-50 or straight 30 should seal it
"I know a thing or two because I've seen a thing or two."
Estraven
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Re: valve section (lack of) compression

Post by Estraven »

I’m thinking marine axle grease. 8-)
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