Explain the water/holding tank system to me?

[truebebeblue]

Does anyone feel ambitious/verbose and want to explain how the water system on my 77 excella works?

A few particular areas I am interested in are;
pumps... when are they used and how many of them? Seems like I might have two? One under the kitchen sink area and one in the bathroom access panel?
Are the freshwater tanks used when you are hooked up or only whilst boondocking? Is the pump(s) engaged only when freshwater tank is used?

Are the grey and black tanks connected in any way or just both dump through the same outlet?
Im planning on replacing at least the black tank.....
Where is a good resource for these?Does the black tank come complete or will I need to install a flange or something?Could a welder fabricate one easier than buying online??! I know a good one....any special considerations?
I know this is a loaded question post... I much appreciate any feedback!

Thanks, TRUE

[azflycaster]

The fresh water tank and pump are only used when boondocking. The pump should have a check valve to prevent the tank from filling when attached to city water. Your pump should be under the sink in the kitchen. What you may be seeing in the bath area is the pressure regulator for city water. These locations are what my 75 Trade Wind would have had originaly.

[wahoonc]

Originally Posted by truebebeblue

Does anyone feel ambitious/verbose and want to explain how the water system on my 77 excella works?

A few particular areas I am interested in are;
pumps... when are they used and how many of them? Seems like I might have two? One under the kitchen sink area and one in the bathroom access panel?
Are the freshwater tanks used when you are hooked up or only whilst boondocking? Is the pump(s) engaged only when freshwater tank is used?

Are the grey and black tanks connected in any way or just both dump through the same outlet?
Im planning on replacing at least the black tank.....
Where is a good resource for these?Does the black tank come complete or will I need to install a flange or something?Could a welder fabricate one easier than buying online??! I know a good one....any special considerations?
I know this is a loaded question post... I much appreciate any feedback!

Thanks, TRUE

True,
The black and grey water tanks are separate but use the same dump outlet port, separate valves. They are availble from several sources. Run a board or google search and you will find the links. They are typically made out of polyethelyne...so I hope you know a good plastic welder. IIRC you can order them with the fittings already in place. The typical water system works one of two ways, if you are using the tank you use the pump, water for the tank goes in the fill on the curbside of the AS. If you are using city water, it goes in via the hose at the left rear of the unit. No pump required.

Aaron