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valve section (lack of) compression

Posted: Sat Feb 26, 2022 8:57 am
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.

Re: valve section (lack of) compression

Posted: Sat Feb 26, 2022 9:28 am
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...

Re: valve section (lack of) compression

Posted: Sat Feb 26, 2022 8:04 pm
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...

Re: valve section (lack of) compression

Posted: Mon Feb 28, 2022 8:58 am
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?

Re: valve section (lack of) compression

Posted: Mon Feb 28, 2022 9:11 am
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.

Re: valve section (lack of) compression

Posted: Mon Feb 28, 2022 11:49 am
by Doug Elliott
20w-50 or straight 30 should seal it

Re: valve section (lack of) compression

Posted: Mon Feb 28, 2022 12:27 pm
by Estraven
I’m thinking marine axle grease. 8-)