[GreenKeys] M15 with Frozen Dashpot

[John Nagle]

I've had that happen. Someone used a lubricant
with heavy fractions, and the light components evaporated leaving
the asphalt component behind. This is why I lubricate machines
with 0-20W synthetic motor oil, which has no heavy fractions.

It's reasonably easy to get the entire dashpot out. Then
remove the top, so you can get the piston out. The shaft
is probably stuck where it goes through the top.
That's metal to metal, so you can use Locktite freeze
and release spray. That shrinks the metal and opens
up enough space for its penetrating oil component to get in.

Once you get the piston moving, take it out and clean
the inside and outside of the piston shaft and hole of
whatever gunk was jamming the piston.

While you have the piston out, check the leather
seal on the dashpot. That's the only leather part
in a Teletype. I suggest lubricating that with
Hydrophane leather dressing, which is a silicone oil
used on horse tack. It won't evaporate and dry out.
(Incidentally, if you just paint that stuff on a
cheap leather jacket with a paintbrush,  in
a day or two the oil will disappear, the leather
will become nice and soft, and it will stay that
way for decades. Doesn't change the color, either.)

			John Nagle