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csorba's avatar
csorba
Explorer
Jun 25, 2013

Extra FW Tank Directly Above Existing

Hi,
First off lets not get into the "Weight Debate". I know that water weighs 8.34 lbs/gallon and by adding a new tank will increase my weights.

I did a search and found many post about adding an extra fresh water tank. The original tank (36 Gallons) is mounted between the frame rails in the under belly.

However my additional tank (42 Gallons) cannot be mounted in the underbelly as there is no room on the frame rails.

So I was thinking about putting the second water tank in the under bed storage area.

This is directly above the factory tank and would only require me to Tee into the fill line (1-1/4") and add a 3/4" gate valve. Plus adding in a seperate fill (1-1/4") and vent line (1/2"). New tank would be secured down and adding the extra FW capacity won't overflow my Grey/ Black water tanks. (using the 80% grey/20% black rule)

Has anyone else done this? issues/potential problems. (Ignoring weight issues)

I will post pictures once I get started this weekend.

5 Replies

  • I forgot to mention that the factory tank had its vent line running vertical out of the top of the tank ( as seen in the forth picture above) and the made a u turn and was routed back through the floor and out the enclosed under belly. It came from the factory this way

    Now I changed it to be hooked to the fresh water fill vent area, where there was nothing attached.

    Just wondering if anyone else think the original method was wrong? Seems like 1 little burp of water would have caused the vent to plug off (making it seem like the tank was full)
  • Here are some completed picture of this completed project ( almost complete, just needed 1 more elbow)

    Hope other people can use this information.


    -New Water Tank installed under bed, from D&M Plastics from Lacombe AB, RFW 1040 model and it holds 168 liters or 44 gallons


    -Vent lines and missing elbow


    -high level shot showing angles and plumbing

    -Close up of gate valve and 3/4 tank and tee fitting. the tee is 1-1/4" barbed by 1-1/4" barbed by 3/4" threaded. The gate valve is 3/4" threaded and I used some irrigation fittings.

    -New water fill mounted above factory

    -New water fill from American RV, this one is lockable and includes a 1/2" vent line as well as 1-1/4" fill line

    -New lines showing back of fill fittings

    -Shows new lines from inside the passthrough to the under bed storage.
  • I have done this on our 2010 Jayco, see my post which is the 2nd from the bottom, couple of pics.

    http://www.rv.net/forum/index.cfm/fuseaction/thread/tid/25923805/gotomsg/25926517.cfm#25926517

    This is under the sofa, just forward of the front axle.

    I'm surprised that your 2011 doesn't have the dual tanks, but maybe only the Jayflight models got them in 2011, just after we bought our 2010!!! And, yes, the ones with dual tanks have them mounted under the trailer and tied together hose wise with a single fill.
  • Thanks, I did some more research and the 2013 model of my trailer has been upgraded to an 80 gallon FW tank. So I am going to have to look at a new model to see where they added the tank. It must be under frame from factory.

    Either way I am adding this one in under the bed. Maybe next year look at what they did from factory on the 2013 and duplicate it.
  • I originally had a 30 gal FW tank; moved it from under the couch and replaced it with 3 40 gal FW tanks under the coach between the frames. Tied two together to effectively make a 80 gal tank added a second fill & vent for the third tank. have 2 valves to select which tank to use. I only fill the 80 gal tank when in a park dry-camping (lots of federal parks) so I'm not dragging 700 extra pounds around on the highway. Added more grey water tanks to accept the extra water.

    As you can guess, I'd do it in a heartbeat.

    Regards,
    Doug

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