Fresh Water Tank Back Pressure

[Chemosavvy]

We have a great 2003 Travel Supreme DS02 40' coach. Not sure if this is a problem but When I use water from the fresh water tank via the pump there seams to be a back pressure at the inlet which is strong enough to leak through the back up valve in the inlet. Just replaced the fresh water inlet with a new brass unit. Fresh water hose not hooked up when this happens. The faucets work fine with good water pressure. Any ideas?

[mmartin]

Not quite sure of the meaning of a "backup valve"? Did you mean "bypass valve", if so there should be pressure against the valve if it is closed and holding. If you have good pressure at all of your faucets then the bypass valve is holding

[Skip426]

If the part you replaced , is the city water hook up, with a back flow valve attached, and that's where your seeing the leak , you got a defective valve .

[Redonion]

Most TS have a check valve under the sink above the water tank. This is a 1/2 line, black check valve hard to find.. (from a dealer) if the valve is bad, water will gush unit the pressure is reduced. Mine went bad, replace with a coupling, now use a hose bib back flow valve, works fine... hope this works,, safe travels
Fred