Valve oil port

[OhTubaGuy]

I thought I had read somewhere about adding a port hole to squeeze oil into a valve without unscrewing the valve caps each time. I couldn’t find the thread.

It sounds simple enough to do in certain locations, but I wonder…
How well does it work?
Do you have more debris entering the chamber?
Is there anything unique about pistons vs. rotors?
What have people already learned the hard way?

[bloke]

I thought I had read somewhere about adding a port hole to squeeze oil into a valve without unscrewing the valve caps each time. I couldn’t find the thread.

It sounds simple enough to do in certain locations, but I wonder…
How well does it work?
Do you have more debris entering the chamber?
Is there anything unique about pistons vs. rotors?
What have people already learned the hard way?

I was the one who did that, and I think a believe a couple of people copycatted me without enough attention to detail and messed up.

First, I kept track of where each cap clocked, so that - when they were all screwed on - the holes lined up and looked nice.
Secondly, I drilled them so as the holes lined up just barely inside the casings, so the oil would run down the casing wall and articulate the piston on the edge of the piston, instead of getting all over the cork-and-felt or synthetic bumper on the top of the piston.
Finally, I used a needle oiler that was sort of fashioned after a writing pen. I could keep it in my pocket, pull it out and quickly oil one or all of the pistons through those holes and not be caught messing around if suddenly the music director asked me to play a passage in a rehearsal. I just grew tired of having to take valves out of casings to oil them went away from home when there was too much activity of others moving about who could have bumped my elbows or something and knocked pistons out of my hands.

I didn't experience any more debris.
The upward motion of a piston actually has a sucking effect on that huge hole in the center of the bottom cap, yet I don't think that sucks in any debris. Rather, I believe the trash that collects in the bottom caps comes from it being pushed to the bottom via piston downstrokes.

[shovelingtom]

I’ve always thought @bloke’s oiler hole mod was super neat too. There are pictures in this thread. https://www.tubaforum.net/viewtopic.php?p=52970#p52970

[bloke]

I’ve always thought @bloke’s oiler hole mod was super neat too. There are pictures in this thread. https://www.tubaforum.net/viewtopic.php?p=52970#p52970

yeah...You can oil from the bottom (but bottom caps are where dirt collects). You can oil from the slides (but you might end up mixing a bit of slide grease with the oil).