About to add a second fresh water tank under chassis

Golden, Thanks. That's good advice. I have the camper at the shop right now getting a new AC. We had some bad hail storms here this spring and I had quite a bit of damage. When I get back I'll get underneath and see if this will work as easily as my original plan.

Jeff,
Those are some great ideas on your site. Many I had already planned on doing plus a few more after seeing what you did. Thanks.

I added a second fresh water tank, but I did mine internally. Some pics here...

http://www.jeff-z.com/rv/amods/amods.html

Hi,

My suggestion is to put in the pump with a bypass valve around it, from inlet to outlet. Then you can open that valve to fill the rear tank with the front pump. You can gravity fill the front tank, then pump the rear tank full as you want it. Then you can use one or both pumps to supply fresh water for RV use, and have a powerful shower if desired (say on the last day when you will be dumping the excess water anyway).

In this way, you could fill the front 40 gallon tank, then put away your garden hose, and then pump 25 gallons into the back tank, and reduce your hitch weight significantly, while still having 40 gallons on board total (for the lightest tow weight). Or fill the rear tank, then the front one, and carry 65 gallons.

Yes with only a kayak to offset the heavy hitch weight, you can use the extra water behind the rear axle. I agree that putting it inside is bad, not just a tripping hazard, but also weight below the floor is better than weight above the floor, due to center of gravity issues.

Putting some 3/4" marine grade plywood under the tank, and unistrut or something strong to support it will keep that 250 pound (full weight) tank in place. 3/8" allthread in all for corners is strong enough to carry the weight, then some.

Fred.

down home wrote:
Find your balance point empty. Usually between the two axles. Move 225 lbs or so, weight of water and tank and hose etc back and forward and observe measurements to bottom of frame of RV on a hard level surface, on both ends. Probably the existing tank is near center. Maybe replace it with one larger one with plenty of baffling. check it with weight of your toys too. May want to think about weight distribution of load of toys and where weight, of extra water and existing water etc sits. Don't want the tongue diving or rising on the towing vehicle. Should sit level.

The existing 40 gal tank is all the way forward just behind the hitch which exacerbates the very high tongue weight on the TV, a Tahoe which obviously is not as forgiving to a very heavy tongue as a 3/4 or full ton would be.

My toys right now consist of kayaks, bicycles and a beer cooler. This is no where near enough to offset the weight of 40 gal of water which is halfway between the trailer axles and the ball. 40 x 8.35 x 50% = 170 lbs of water on the tongue. If I remove that plus the 25 gal that are about 50% of the distance of the trailer axles (fulcrum) to the ball behind the axle then 25 x 8.35 = 210 lbs on the trailer axle and because it's behind the trailer axle it should remove another 100 lbs+ from the hitch. All said and done it will take 270 lbs off my overloaded RAW.

Also the places we go very rarely have hookups so we need to bring our water with us. We end up with less water overall but I can make a few trips with jugs.

When we do get some heavier toys, ATVs, etc I can adjust the weight and balance as needed and can possibly find a place close to the CG to fill everything up for extended stays but for now I need to get some weight off the ball.

A heavier TV is on my also on my list but not in the cards for the next year or two.

Find your balance point empty. Usually between the two axles. Move 225 lbs or so, weight of water and tank and hose etc back and forward and observe measurements to bottom of frame of RV on a hard level surface, on both ends. Probably the existing tank is near center. Maybe replace it with one larger one with plenty of baffling. check it with weight of your toys too. May want to think about weight distribution of load of toys and where weight, of extra water and existing water etc sits. Don't want the tongue diving or rising on the towing vehicle. Should sit level.

My toy hauler had two 75 gallon tanks. They were tied together at the fresh water dump valve with an additional valve added so you could fill just one tank or both. When using water, it could pulled from just the first tank or the valve could be opened so both tanks were supplying the pump.

2oldman wrote:
If you regularly camp where there's no access to water, then this might make sense.

What's much more flexible, and easy, is to carry spare water on the TV. Then pump it in from there.

That's what I do on extended boondocking stays. I have 4 blue 7 gallon fresh water jugs that I fill up and put in the back of the truck.

2oldman wrote:
If you regularly camp where there's no access to water, then this might make sense.

What's much more flexible, and easy, is to carry spare water on the TV. Then pump it in from there.

Actually one of the main goals is to get weight off the TV and tongue but I usually have enough stuff in the garage already I don't want to just throw water tanks in the back of the TH.

If you regularly camp where there's no access to water, then this might make sense.

What's much more flexible, and easy, is to carry spare water on the TV. Then pump it in from there.

The only advice that I can offer is be careful of weight and buy a Tank that has baffles in it to minimize sloshing!