Community Forums

rarebear.nm · 09-19-2015, 11:40 PM

I have a Excel 2007 30RSO. My grey water starting leaking through the bottom insulation when the tank was about half full. I have not starting removed anything yet thus do not know the source of the leak. I do all of my own service on this rig. Questions are: 1 what material is this tank made from? Guessing ABS or PE. 2 best options to repair the tank. 3 removing and replacing the bottom insulation. 4 best ideas to better strap the tank afterwards. I have searched several threads and seen some of heavier duty straps used. Any info and pics would be really great.

Do I need to cut the bottom open or does it drop as a unit somehow?

Usually I do not drive with much in the waste tanks but there are times I must to reach a dump station.

Thanks

rockintom · 09-20-2015, 08:38 AM

Hi there rare,
The grey tank is made of ABS. You can find all kinds of stuff we've posted over the years on this subject. Just search this Excel forum using "grey tank" and "rockintom" as the author. Also the latest guy to attack this issue is David2. His recent threads have lots of info. HTHs rockin'

rarebear.nm · 09-20-2015, 09:53 PM

Thanks for the info. Today I opened the underbelly to locate the issue. Turns out it was the black water tank's medium level probe has gotten bent somehow and barely in place. It fell out in my hand when I touched it. I order a full set of Horst tank probes to replace all factory installed probes. These probes are built very differently and users seem to love them. Owners seem to get reasonable tank readings over the long haul.

I shot lots of pics today and will add more as I close up the underbelly and post to this thread.

rockintom · 09-20-2015, 11:02 PM

Glad it was something so simple. You only opened the inspection cover right to gain access. You'll love the Horst probes, I heard good thing on them too. Thanks for sharing your story. That is weird that something hit the probe.....musta been a wine bottle fell in your cellar!!! Ha! rockin'

Max1 · 09-20-2015, 11:38 PM

Hello rare, I also have the 07 30RSO and would like to hear from you how robust your factory strapping looks. I have not opened mine up and would like some more info> Thanks

rarebear.nm · 09-21-2015, 09:15 AM

The leak had soaked nearly all of fiberglass insulation forward of the axles. Thus I opened the driver side and front edges of the underbelly to pull the old insulation.

There are two forms of tank supports. The tanks are constructed with a flat top that extends out as a flange. Three full length heavy steel channels support the tank flanges. The two outside edges have angle steel attached to main frame members while the center support for both tanks is a U shaped channel on its vertical edge. The gray water tank has two light weight, in my option, steel straps, while the black water tank has only one strap, they run length wise across the bottom of the tanks. Empty, I could get a full hand between the tank and strap. I filled the gray water tank to test it for leaks. While filling the bottom settled until the straps were tight. My concern is that the center area of the tank seems to drop below the straps and this is a large unsupported surface. Today I will be adding some more straps and new insulation. I'll post again with details with some pics when I finish.

rockintom · 09-21-2015, 05:39 PM

rare,

I hear ya on the strap situation. As you probably read, I used 22 (I think) gauge plumber's strapping with larger hex headed screws with a built-in flat washer (seems they were #12). Lot more robust than those puny little things they used at the plant. I would run some across the width of the tank (perpendicular) to the original straps.

Major caution. Do NOT install those straps tight with an empty tank. You'll lose lots of tank hold capacity, plus may stress the top seams of the tank when near full. How much? That's a judgement call. You have your old straps to compare to. Mine were all broken, so I had to guess.

Just to give you example of how much that tank swells when full......I tested it with the old tank. With just the side angle iron supports when full the center of the tank drops 6-7" BELOW the frame of rig. Unbelievable sight to see. May want to put a couple 2 or 3 external straps (belly straps). Just for safe keepin'. Just sayin'

Max1 · 09-23-2015, 05:07 PM

rocking,
My straps are still holding

but would like a straight forward suggestion for reenforcing, drop insulation? locate tanks? or just strap over the outside? other options?

rarebear.nm · 09-23-2015, 10:07 PM

Max1,

Since I started this thread I've learned lots a outs this. The internal straps are above the insulation. Thus the insulation does not get compressed as the tank fills, at least due to these straps. Don't know how cold you operate in, but we are looking full winter use.

As noted in many places the factory internal straps are light weight and attached by single screws like the ones used every where else on these rigs, #8 x 1 1/2. I presently have the full underbelly open. I will be adding two more long straps and two or three cross straps to each tank. I'll use #14 x 1 1/2 screws for all straps. My existing straps are loose enough to get three hands between the strap and tank when empty. When full, they are tight. I will also add a couple external bars, li,e 1/8 x 2 in steel straps under the tanks as a back up measure.

I'm also beefing up the insulation. Keep in mind there's a furnace duct that feeds hot air into the space between the tanks and needs to circulate all the way around both tanks. I've added some foam board strips between the frame members and tanks. Will also use thicker fiberglass insulation as I close up. The old insulation was soaked from a blown out level sensor, original problem. I'm also placing a layer of foil covered form insulation, very flexible stuff between the tanks and the internal straps.

I think we see quite a number of rigs with broken straps that lead to leaking tanks or sometimes loss of the entire tank on the road. That has to rate up there with tire blowouts. To me the cheap insurance to add good internal straps with backup external straps of some kind.

When I finish this project I'll post a detailed summary with pics. I replaced all eight tank sensors today with the better Horst sensors. No results yet.

Max1 · 09-23-2015, 11:06 PM

Hi rare,
Lots of good info but am hesitant to drop the insulation.
Is that what others have done prestrap breakage?

rarebear.nm · 09-24-2015, 06:20 PM

Max1

I expect to close up the underbelly in the next or two and will reply with my story then. I hope that it's not TOO bad to do. But I had little choice. I understand your reluctance. I have no way to say what anyone else has done. Perhaps Rockingtom has meaningful input on this.

rockintom · 09-24-2015, 07:37 PM

rare, I think I covered it pretty good on this recent post. Post # 3. rockin'

Max1 · 10-01-2015, 01:52 AM

Is everyone doing this Excel strap modification pre breakage? Any thoughts from the masses?

rarebear.nm · 12-03-2015, 11:28 PM

Its been a while since I first posted this thread and more has happened since. On another trip I found I was still leaking from the black water tank- again. When I got home I pulled all of the underbelly off and filled up both tanks. The black water tank was leaking at the forward end on the very top of the tank. After lowering both tanks about two inches and feeling around the leak area found a small hole right at forward top edge of the tank. There was a screw protruding from the floor into the tank. A factory installed screw! I used a dremmel tool to grind off the screw and patched the hole with a small square of ABS from Plasti-Mend. Thinking I had it fixed, remounted both tanks and did another fill test. This time another leak occurred from the backend of the same tank. Getting tired of this exercise I just totally removed both tanks. With the tanks removed I counted 11 more screws protruding from the bedroom floor, one of which had punctured the tank at the back end. With both tanks removed, I patched the second hole and did a overfull test with the tanks on the ground. Its amazing how much those ABS tanks expand when full. At last everything stayed dry. I had cut all four ABS drain pipes at mid length between glued joints. In closing up I used heavy duty rubber pipe repair couplings with stainless steel straps to remake the joints I had cut. This worked very easy and would allow a subsequent drop to be made if ever needed, hope not. I had both tanks in-place and reattached and strapped in about 30 minutes, not too bad working alone. A final tank fill test confirmed the tanks and all connections were water tight at last. Since I had just cut the underbelly fabric out and trashed it, a new bottom closure material was needed. I bought three 4 x 8 ft. sheets of Coroplast. This is a cardboard like material made out plastic and easy to work. It was attached with screws into the same wood strips the underbelly fabric had been attached to. To apply even pressure along the edges of the new bottom I used 1/2" x 1/8" aluminum flat strap under the screws. 1/4" holes drilled on about a 12" pattern into the Coroplast allows water out if ever needed and small enough to keep mice out. I had found a number of dead mice caught in the old fiberglass insulation, thus a desire to better mouse prof the bottom. Another detail was to install 1/4" wire screen on the ends of the two furnace hoses heating the tank areas and behind the cold air return duct under the interior steps. To make dump valve service easier in the future I closed-up the 18" wide area between the holding and fresh water tanks with a section of insulation and Coropast independent of that covering the holding and fresh water tanks. After having spent too much time under our rig I'm ready to be on the road again.