Uwe,
Airstream apparently started installing sewage holding tanks around '58
or '59. Prior to that time the "dump to daylight" system seems to have
prevailed. When in a park, the sewer outlet went to a sewer, and when
boondocking, to a "gopher hole".
After black tanks appeared it took a while for the present dump valve to
evolve. I have never heard of a dump valve like the one you describe in
your '58 Traveler. (Another '58 Traveler that I have seen was "dump to
daylight".) I have also never heard of another bronze wedge gate dump
valve like the one on our 1960 Pacer. The gate is in the shape of a
wedge, tapering from an inch thick at the back to half an inch at the
front. The seat has a matching taper, so the pressure on the mating
surfaces is high when the valve is pushed shut.
The seal is metal-to-metal--not a gasket in the entire valve. The
secret of a liquid-tight seal is that the valve body is packed with a
thick grease, made for the purpose, which provides both lubrication and
sealing. It works great--I rebuilt the valve several years ago (it had
been frozen, so it took some metalworking) and it hasn't leaked a drop
since.
If the mating surfaces of the plunger valve you describe fit fairly
well, it might seal with sealant grease. I don't know how the grease
would be replenished as it is in the gate valve. (In the wedge gate
valve, the gate is hollow. A little more grease pumps out of the valve
body each time it is cycled.)
If you want to try it, email me off list and I will send you a sample of
the grease. (A minimum order was more than I'll ever use in the Pacer.)
It's about the consistency of peanut butter, and is specifically
listed for sewage service.
See you down the road,
John & Barb Sellers
WBCCI/VAC #1587
1960 Pacer
1980 International Caravelle
Dayton, Ohio
> Here I go with yet another question for the 50's Airstream crowd..
> I noticed recently on a 1958 Traveler that the dump valve is located
> inside the black tank. It looks like a plunger made from thin brass,
> and simply closes off the bottom hole in the black tank that leads to
> the outside.
> The plunger has no signs of an O-ring, or rubber on teh bottom, where
> it is supposed to seal against the exit hole in the tank. Of course
> it does not seal the exit hole.
> Has anyone successfully rebuild such an animal, or is it better to
> lose it and install a modern slide valve to the existing dump elbow?
> It could be a decent little system, if it can be restored.
> Help, information, suggestions are much appreciated, as always.