Noisy 1st valve mystery.

[pjv]

https://www.facebook.com/1093789061/pos ... 13589/?d=n" target="_blank

I’ve posted a film and picture on my FB.
Anyone? Help? Please!
I’ve checked everything. Even unlikely things like the lyre screw, any and every solder joint, even the bell ring. All screws are tight. There’s no play in the valve, the backplate screw is snug, there’s no vertical play in the valve pedals. Stop arm has no play and it’s not bumping up against any metal (that’s also pictured on my site).
If anyone has an idea I’d appreciate it.
Thanks.

[Matt G]

Every once in a while, my old Mirafone 186 would get like that. The rear bearing plate on one of the valves would scoot out a bit. A few gentle, loving taps of a wood mallet would reset the plate and quiet the valve.

[pjv]

The rubber on the up stroke and the cork on the down stroke are both the same age and the same age as the rest of the valves. Everything is as tight as possible, even the cork plates. I copy/pasted a post years ago you wrote here about "The primary causes of clicking rotary valves" and went down that check list to make sure.
Stop arm sticking out above the valve stem. I'm trying to visualise how that would look.
Is by chance this present on the link I posted?? It's a 2 year old Miraphone 496. I wouldn't expect something like this to pop up out of the blue.

[pjv]

Thanks Matt. I'll give it a nudge tomorrow when I'm back in my practice space.
And if that doesn't work I'll replace the cork, rubber stops and pull the valve entirely.

[bort]

Unlikely, but did you check the screws on the "horseshoe" that holds the rubber bumpers? Or, maybe the top cap of the rotor casing is a little loose?

[pjv]

Yes I did. Thanks.
Thats what I meant by cork plates, but maybe that's not the proper term.

[bort]

Yes I did. Thanks.
Thats what I meant by cork plates, but maybe that's not the proper term.

You're good, I just missed that part.

[pjv]

I didn't get to my tuba today because of unexpected family business.
Thanks for your time and wisdom.
Tomorrow I'll get to this....
PS, why after tightening the center screw do you do the micro "back-off"? I mean, I just tightened it.

[Rick Denney]

I didn't get to my tuba today because of unexpected family business.
Thanks for your time and wisdom.
Tomorrow I'll get to this....
PS, why after tightening the center screw do you do the micro "back-off"? I mean, I just tightened it.

Because if it's tight, it will bind the valve. You loosen it just enough to avoid binding, but not enough to create play that can allow the valve to rattle. Tightening it until it binds is the only way to know that you really tightened it. The backplate should already perform this function--doing it with the screw is a diagnostic step that just means the backplate isn't doing its job. The backplate may need to be tapped in all the way (that was suggested upthread), or it may not be fitted exactly right (which can be fixed). But identification of that as the problem is the first step.

Rick "who isolates each joint in the linkage to look for play" Denney

[pjv]

Got it. And yes, as I feebly tried to show in my video nothing moves when isolated. Quite difficult to demonstrate with one hand.
But the good news is: I came back to my rehearsal space today and....it’s over. No noise. I did nothing.

Bad new is it’s still a mystery. Thanks everyone for the advice.

[bort]

Great! It's like a computer... Restart, wait, and all better!

Is it hotter today? I wonder if metal expanding is temporarily fixing it?

[pjv]

Actually it’s been a little bit colder and rainier.

[Matt Walters]

Bad new is it’s still a mystery.

No mystery. The oil finally got past a dry crud seal that formed and got inside the rotor shaft in the casing area. You got lucky you didn't need to pull the valve out.

[pjv]

and I thought I'd purchased a Miraclephone.

Thanks y'all!

[pjv]

Also good to know. Thanks.
What do you advise non-professional repairmen (players) to soak their valves in to de-crud them? Cleaning vinegar? Soda?
My East German B&S has some green here and there that could use attention.

[pjv]

Yeah I'd rather not take any risks with if I don't have the guarantee that I can wash it off (on time!).

Thanks.

[pjv]

And what's this "stuff" called?

[pjv]

Do you know it's official chemical name? Maybe I can take it from there. And if you'd rather not post that here please PM me.
Thanks, Pat