Hagman Valve Maintenance?

[Mamaposaune]

This is more to satisfy my curiosity, but will gladly pass along any tips to my student.
I have only owned trombones with rotary valves. I have a student with a 42 with a factory Hagman valve; he told me that when he bought it at Dillon Music the guys there went over how to maintain it. He has also watched videos online.
During a 45-minute lesson, he has to remove the bottom cap and let the valve drain several times, in addition he sometimes wipes the inside with a clean rag and gets greenish colored crud out. At his last lesson he had to also add oil because it was sticking. (It had sat for a week while he was on vacation)
Is this normal? Is there something more that he could be doing? It seems to be excessive, at least in comparison to a rotary valve.

[Burgerbob]

Sounds about right.

[RoscoTrombone]

So far I've never had to to drain them during playing other than blowing water from the slide whilst engaging the valves but do find water sitting when I remove the caps.
I do have to oil them after every time I play otherwise they go sluggish/sticky.

[SwissTbone]

Bach does a very bad job at installing Hagmann valves. What you are describing is absolutely not normal. I have a tenor and a bass trombone with Hagmann valves - installed at the Hagmann shop.

They have been basically maintenance free for 20 years. Some oil once a week and I NEVER had a sticky valve.

[blast]

Hagmanns vary a lot. Some stay clean, some go green. Some get sticky, others stay free. I oil my Hagmanns under the valve cap and through the tubes before every use. That gives them the best chance. They will need a strip down every so often. I've owned many sets. They blow great but are fiddly to maintain .

[Wilco]

Never had an issue with Rath, Courtois and now Thein. Oil them! (As you should with any valve)

[OneTon]

I use Holton Rotary Valve Oil on the valve every time I use my LT42AG. I occasionally put some Marvel Mystery Pneumatic oil (not the red stuff) on the spindle. It has never turned green, never got sticky, and has never been apart in ~25 years of service.