valve problems

[tuba114]

I was warming up this morning and my horn was just not playing the same. After looking over the horn I noticed that there is a bulge on top of the 1st and 2nd valve. Is this anything? I've never come across this.

Thanks for your help!

Here's a pic so you can see
The left valve is the one that has this odd bulge

v24.jpg

[tuba114]

VMI Mel Culbertson Neptune. I believe it has the same valve section as a B&S PT-7

[Dan Schultz]

That's REALLY odd and is gonna mess big time with the accuracy of the PVAK.

It looks like the sort of thing that is the result of being frozen while full of water.

[Dan Schultz]

Thinking about my earlier post.... I agree with Bloke inasmuch as those caps are usually pretty thick. Maybe as thick as 3/16" or thicker. I don't think freezing water would do something like that without separating the solder holding the cap to the piston shell.

I wouldn't risk damaging the piston by trying to drive the top back down. IF the dome is affecting piston alignment... I would be inclined to chuck the piston in a lathe and cutting the dome down until it's square. I know the stems in the York Master, Marzan, and Bohm & Meinl pistons are brazed in from the underside of the cap before the caps are soft-soldered to the piston shell. If this is the case... the safest way is to unsolder the cap/stem to do the machine work.

Of course... it it's NOT affecting piston alignment... just leave it alone.

[tuba114]

It's fixed!
A repair man here in the DFW area was able to fix both valves. He said it looked like someone had picked up the tuba by the valves??? No clue how that happened? I'm just glad it's fixed!

[Dan Schultz]

It's fixed!
A repair man here in the DFW area was able to fix both valves. He said it looked like someone had picked up the tuba by the valves??? No clue how that happened? I'm just glad it's fixed!

That's bizarre! Glad you got it fixed.