I don't want to start a long 'argument' ... but I feel I have
to say what it is that I know (or think I know) that relates to
the color of the brake hoses, the glad hands, and the angle
If my observations are correct the way that the air hoses
work is that the end of the air hose has a rubber grommet
(doughnut) in a cavity in the glad hand. And the other
glad hand has one also. And the two are compressed to
each other during the coupling up of the hoses in such a
way that the rubber grommets form the seal and the
hole in the grommet allows the air to flow thru the hose
My recollection/observation is that the glad hand is a
cast metal piece - possible with some milling to form
the grommet cavity and the faces of the 'lock' that holds
them together. Definitely "no moving parts". You 'simply'
bend/twist the joint to make/break the coupling and the
casting of the metal forms the 'lock'.
I always have thought/assumed that the glad hand was
'just' cast iron/steel. And therefore the rusting of the
exposed surfaces is guaranteed by time. But the part of
the glad hand that the grommet contacts is kept smooth/
clean enough by the pressure/contact/compression of the
rubber grommet that it forms the seal.
I do not know what kind of metal is/was used on the
glad hands. Not sure I really care. They are probably
more than one kind of metal depending upon the
manufacturer and/or era.
Same is true for the angle cocks. The only part of them
that needs to be clean is the internal part that is the
actual valve. I would not be at all surprised to learn
that in the era of this list they were usually either
cast brass or cast galvanized. With some machined
surfaces/parts. And, since they activated with a 90-degree
turn they were most certainly a ball valve of some sort.
My observation/experience is that both are "always"
dirty/rusty in color (some shade of brown/tuscan/whatever
you want to call it). Perhaps they started out as galvanized
but they quickly got "too dirty to tell".
The hoses usually started out as black but a few were
red ... and they both got essentially grimy black quickly.
- Jim Betz