Posted by Alex with a pretty reliable answer on March 03, 2000 at 14:26:26:
In Reply to: Noisy Valve Problem posted by Matt A on March 03, 2000 at 07:11:45:
My pt-10 was noisy for the longest time, I used blue juice, al kass, selmer and other oils, and I took apart the valve and lubricated everything I could find.
Then I asked a tbone playing friend what she used to keep her rotor quiet. It's a low viscous oil called super-slick. I had Fritz Kaenzig recommend the stuff, too. It was a simple, cheap cure that lasts and is easily renewable if it fades. This will probably be the cheapest experiment, and it works great on my german rotors as well as my junkyard holton's rotor.
you can order the stuff online from Dillon.