Re: [A/S] Water leak

[Charlie/Betty Burke <cbburke@xxxxxxxxxxxxx>]

Some how I missed the original so I'll jump in here.
First off there is no check valve under the sink. There are low point 
drain valves and such but no check valve. The check valve ( or back flow 
preventer) is normally located in the roadside rear corner above the 
floor behind and below the cabinets. The purpose of the backflow 
preventer is to stop outflow of water when you are using the onboard 
pump and tank for water. Otherwise the water would be pumped out through 
the city water inlet.

Location of the leak will point to the problem. It is common for a leak 
to appear near the rear end of the coach which when looked at closely is 
comming out of a hose or a hole in the belly pan. The reason is 
Airstream in a moment of over engineering included a pressure relief 
valve in the city plumbing shortly after inlet. Unfortunately the valve 
is more prone to leaking and eventually flowing than helping "save" the 
plumbing. Airstream installed these valves in all copper systems of the 
70's for sure. Not sure about earlier years.
Because the water heater has a similar has a similar relief valve it is 
an excepted practise to simply eliminate the offending valve. A 
challenge with no trunk to access it but doable.

There are three or four low point drain valves in your coach, usually 
red handled, two in back, two in front, buried below and behind cabinets 
which can leak or if bumped flow.

Charlie