Underbelly Removal

[jwedell]

Has anyone removed the underbelly on their 5er. After I dump the tanks I have a very strong foul smell (probably leak on the black tank)however it only does it when the black tank is completely full up to the toilet (I fill it with water to get a good flush). I have the Good Sam CSP insurance but no one on Long Island will accept it. So if it isn't hard I will tackle it myself and fix it if it's a minor repair.

[Art-n-Marge]

This problem can be caused by a bunch of things and not necessarily a leaky tank. Maybe you can contact Good Sam and locate the closest place that honors them, to have an expert look at it.

I do know that the underbelly is several pieces that overlap starting at the rear. I'd be nervous about crawling under the rig to remove the cover screws that no "liquid" drops on top of me.

Let us know what you find out.

[jwedell]

Thanks, That sounds like a good idea.

[Jolu]

The belly pan is not all that hard to remove or drop to the side out of the way. I think the new units may have a one piece pan. My 08 has multi pieces overlapped. You simply remove the hex head screws holding it on and you can drop each piece except the ones where plumbing or other things drop through them. Those you would need to slide aside or cut the pan for removal. You can then access the tanks. There is a bubble type reflective insulation above the belly pan that will drop also. Then there are cross members (trusses) with aluminum floor joist on top of them. On top of the trusses there will be a vapor barrier with thin insulation above that which insulates the floor. You can cut the vapor barrier and tape it back together. I used black heavy duty duct tape. Much sticker and stronger than the usual tape.

Others have posted describing the smell that you describe and there has been a leak from the tanks. Some cases the tank has been cracked at the fill inlet or at the outlet where they go into the tank. Those would be good areas to check. Theses tanks are thin and it is possible there may be a crack someplace else.

You also need to check around the base of the toilet for leaks and the inlet in particular since you say you only get the smell when you fill the tank completely full up into the toilet. Your toilet gaskets may also be bad. If you have the Sealand toilet they are easy to take apart and check. There are gasket kits and new pedal springs for the Sealand toilets and they are about $50 each.

I don't think I have ever filled my tank to where it is up into the toilet. I would think that is a sure test for any of our tanks and toilets. To get a good flush you really don't need to fill it that full.

[richfaa]

On our 06 3400 the Grey and black tanks are in the front of the camper. The Galley near the front axle and the fresh at the rear. The front two belly panels are not real hard to drop other than a zillion screws and you will have to cut around some of the piping. If I made that sound easy..it is not. Black and Grey tank leaks are not uncommon. That it only smells when you dump is puzzling?? That it does it when full makes sense as there may be a leak at the top of he tank. Try not letting it fill up then dump and see if you have the smell. We have had our front two panels down several times. It is not a pleasent task..

[ols1932]

I'd like to make a suggestion for anyone removing any part of the underbelly. That is, when you button it back up again, use fender washers under the head of the self-tapping screws. It just gives you more security of the holes in the underbelly if you have to remove them several times over the life of the rig.

Orv

[Jolu]

Orv makes a great point about using fender washers when the screws are replaced. The screw holes do get smashed and rounded out when the screws are removed and reinstalled more than once.

[Art-n-Marge]

FYI - Fender washers provide a greater bearing surface under the fastener. This helps prevent a nut, bolt or screw from pulling through the material especially when the material is soft. The opening in the center is small and the diameter of the washer is large in comparison.

You'll need a boatload of them because there are a boatload of hex head nuts holding the underbelly covers.

[jwedell]

Thanks all for the info. I may get under it and take a peek.

[Devildog]

I occassionally get the smell you are describing when dumping also. After much looking, I found it to be the vent in the middle of the bedroom near the toilet room. My Black water vent is just outside that vent, and when dumping, it would draw from the vent (wife usually had the entrance door open which was drawing air outside the camper, or had the fantastic vent on causing negative pressure inside the camper.)
Started closing the vent after showers and installed a 360 degree cap that works with the wind. Has eliminated the odors backflowing into the camper. Also, started using more water with each fluch, which reduces smell and allows the black tank to dump easier and cleaner.

[sreigle]

We also get the black tank smell when dumping if the tank is full or nearly full. I think I will try Jim's suggestions.

[cmp-shooter]

I'd like to do that to mine and see if mice did anything under there...or at least look around
also the washer deal is a good idea.

[Exnavydiver]

I have been into the underbelly several times, once when the black tank ruptured and I dropped the front three panels and cloroxed everything under there before I took it to the dealer. I also had a black tank flush fitting snap and dropped it again. It is not that hard and for the panel that has the plumbing fitting through the dealer sliced the panel from the fitting to the nearest edge and taped it back together afterward. While I was down there the last time I took all the reachable wiring and hung it from the upper frame members with tie wraps. I also separated the wiring from the hydraulic hoses as I had just read in the forum of a couple near fires when a short melted the wiring bundle and the hydraulic hoses together causing leaks and smoke. The wiring bundle was sitting on the belly pan and frame junction on top of the self tapping screws. I did not like this situation so in front of the axles all the belly wiring and hydraulics are suspended from above whit a bunch of tie wraps. Just a safety thought while you are under there... Dave

[crandallbradley]

When I first had my unit I would get smells when I dumped I found that closing the grey tank and the galley tank at dump time stoped them.

[KTManiac]

Always, always, make sure to close the grey and galley gate valves before opening the black tank valve! In fact, it is best to close them a day or two before dumping the black tank so there will be some volume of soapy grey water to rinse the sewer hose after dumping the black tank.

[blamb]

You mean you're not supposed to have a smell after dumping? I thought this was normal. My whole RV stinks up inside when I dump mine after they've gotten pretty full. I just figured it was the fact that the black tank was empty and there's a lot of stinky air coming up through the toilet. Should I be worried?

[Stichwerks]

If you get into a jam and need to replace some of the belly material it is coroplast that sign companies use for short term signs. It is available in small pieces or 4X8 sheets. Comes in a few colors and is cheap. My cost is about 8.00 bucks a sheet. When you tape up the seams on your existing bellys use alcohol to clean the surface and then use a good quality duct tape. They also sell a special razor knife that goes in the flutes of the material and makes a perfect straight cut(for those of you that have to have all the speciality tools). You should be able to get the coroplast at most sign shops.

[KTManiac]

quote:Originally posted by Stichwerks

If you get into a jam and need to replace some of the belly material it is coroplast that sign companies use for short term signs.....

It is also known as, Corex sheeting, Corflute, and Fluteboard, just in case, if you get the blank stare from the salesman.

[vgforbes]

oh oh READ my "black Water " topic just posted on this forum. I did the deed myself and its not complicated. Just remove all the screws(bolts) holdine each side of the panel covering the black water tank and pull the shielding down . Now you should be looking at the black water valve for the tank. If the leak(like mine)only happens when the tank is getting full, I suggest you examine the connection between tank and valve , the valve itself, or (after dumping the tank first,...proceed to fill it with water till it starts to leak....ya its ugly.... replacing the tank is unbeleivably expensive , but leaks can be fixed with JB Weld applied to dry surface (I roughed mine up with coarse sand paper) good luck...wear golves ,face mask and goggles for the overhesd work yuck!!!!