David Dewey Wrote:
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> Some time back the UP steam crew put up an update
> video stating they had sandblasted the air valves
> and coated the insides with some special paint.
> Now all I've ever been taught about them is that
> you do not put anything gritty on/in the innards
> and you clean them chemically. All work needs to
> be done in a clean-clean area, and best by
> experienced hands, or under the watchful eye of
> experienced hands. They're somewhat like
> automobile automatic transmissions--there are
> parts in there that do magic, and you can let the
> magic out if ya don't know what you're doing. Any
> coating applied (other than plating and that can
> be questionable) can flake and cause many, many
> problems; lots of little passages there for stuff
> to get stuck in/on.
> Now before someone posts, "What do YOU know about
> it?" Well, I never rebuilt one on my own, but I
> did assist once a long time ago in a place far-far
> away and my conclusion was, "leave it to the
> experts!" Unless a dire emergency, and even
> then....

Consider this:

Not one of those guys have ever seen the inside of
a brake valve, distributing valve, or any other
kind of brake equipment.

That shop is not an AAR or UP air shop. It has no
clean room, no established procedures, no specialized
tools, no clean air supply, no test rack, and no
parts.

Nobody in that shop has ever had any air brake repair
training.

Gee, what could POSSIBLY go wrong?