Noisy valves

[Tightwad]

Hello.
I’m wondering what advice folks might have to quiet down some noisy valves. The instrument is a wonderful 1923 Besson Enharmonic euphonium that I’m quite smitten with, and the valves operate fine for my level of playing - they’re just noisy. I’m using Monster ‘Smoother' valve oil (their thickest). I’ve read about and seen the following and am wondering what folks have had success with -

-Replacing the metal guides with nylon ones
-Replacing springs with coated one (Mead Springs?)
-Wrapping the bottom of the spring with thread
-Putting a gasket/washer in the bottom valve cap to add some cushioning

If you have a fix you’d recommend that requires parts, a supplier in the States would be helpful and appreciated.

Thanks so much for any ideas and suggestions

[Sousaswag]

Replace those valve guides.

I’m having that done with my Holton 340, which has top mounted metal guides.

The other thing about springs - if they’re rattling/scraping on the casing, replace them. Those Mead springs sure are around, but the Yamaha springs work just fine.

If you haven’t had it cleaned in a while, do that. When felt gets soaked, it doesn’t cushion nearly as well.