Waste tank under shower floor...

I apologize up front if I sound somewhat unintelligent but this is the first time I have ever owned a RV and I am still learning my ways around it.

So first and foremost, thank you to anyone that may be able to help.

I have a 1994 Hi-Lo Towlite that I received from a customer (payment) that I just learned has a crack on the inside of the waste tank that rests under the toilet/shower combo. The tank itself cannot be seen under the RV (all I see is the drain/dump valve and plywood.

I am pretty sure I can fix it (based on reading other posts regarding cracks, ie JB weld abs plastic/fiberglass) but I am not sure exactly how I can access the actual tank without ripping up the shower/toilet floor and dismantling the vent pipe that serves the grey water holding tank and waste tank.

Whenever the toilet is flushed the water drains on the outside of the drain pipe vice thru the drain valve.

Is there any tips/tricks/inside information that I can access to help me thru this process?

Once again, thank you for your help.

Hi; Welcome to the forum. Where in VA are you located? I am just west of Charlottesville. I would be glad to help with the crack and educate you on the HiLo if you would like. I have repaired these tanks a number of times thru the the years. I have sent you a private message.

I feel so left out…. I too have a cracked black tank.

Welcome to the forum

No question is dumb. The only question that is dumb is the one you don't ask!! Our forum members have many years of ownership and experience. A very friendly helpful group.

A common area in the black (and grey tanks probably) that is prone to developing leaks is around the collar that the waste pipe fits into at the tank. The tank walls are somewhat "flexible" and the collar is very rigid, which means that the joint between the collar and the tank will eventually fail.

It is easily repaired though. I used ABS cement (NOT PVC cement!) and layers of fiberglass cloth. After cleaning the area around the collar (using something like 409) to remove heavy dirt, I first used a generous wiping of ABS pipe cleaner to prepare the surface. Then, I applied a heavy coat of ABS cement over the flange of the collar and the surrounding tank. I then pressed in a layer of fiberglass cloth and followed that with another coating of ABS cement. The entire repair had a uniform "black" look when I was done. I allowed that to dry overnight and then repeated the cement, fiberglass, cement process again.

The result makes that side of the tank quite rigid and the collar is bonded to a large area of the tank. This repair has held up well now for one camping season. It does not seem to be weakening at all.

- Jack

Jack, did you complete your task with tank removed? If so, what fittings did you need to reassemble the pipes at the discharge. I may have to do this, as I was cleaning the black tank, filled it up with water and Pine Sol and noticed a flow from the top area of the tank. Only two fittings there stink and toilet.
Tree

Sorry, Tree - no, I did not have to remove the tank to do my repairs. I suspect that can be difficult at best! It's easy enough to unscrew the metal braces holding it in place, but how the heck does one separate the fittings at the top if they're glued, and then how does one reglue them when replacing the tank? Maybe they're just slip-fit in place? Still, you also have to disconnect the waste line, which I guess could be done by removing the slide valve.

If you have to do this, let us know what you find!!! At least the tank should not be heavy if it's empty!

- Jack

I have recently removed my black tank, however I have not fixed it as of yet. As far as removing it, Of course I had to remove all the screws, however to get to them I did have to remove the plumbing that attaches to the grey water tank. When removing the tank the stink pipe was glued into the black tank. I just barley had enough room to get a hack saw in there and cut it off. From there is was all about getting the toilet off which for me was no easy task since I had a rusted out bolt that was determined to stay. My tank is smashed in from the front along with a crack on each side. Normally I would throw something this damaged away, however there is no replacement so I purchased a product called plasti-mend. It will be a huge task to put it all back together but I think I can do it.

Tree, (and Jman) I did an internet search after posting above and came upon this:https://itstillruns.com/remove-black-water-tank-rv-6462817.html

Of course it's not for a HiLo, but I would not be surprised if the way tanks are installed is not fairly "standard". Note you have to remove the toilet, which should not be TOO difficult (I've replaced one in a home), and it seems to mount in much the same way.

In the link, they say the stink pipe might unscrew. If so, that would be the only other difficult thing I believe.

So, you might try following that advice to remove yours. I think a simple crack could be easily repaired, if you had access to it.

- Jack

Thanks Jack and Jman. I'll put this on the "later" list as we've never noticed any odors. I'll remove the toilet first, maybe I'll have enough room to make the repairs. If not, I'll go from there.
Thanks for the link.
Tree

I am a retired plumber.
There is a drill bit tool you can get at HD that goes into a drill. You use it to drill out the old abs fitting to replace with new.
Thus you can cut the offending joint at center and remove joint, drill out and replace.

This tool fits inside of the abs joint and drills out the pipe that was originally glued into it. You will need a strong drill, I use my 1/2", and some muscle to hold.

Glad my tanks are intact!

To those that complain about tank stink there are products to put in and will remove all of the offending smell. You drive with it in and dump as usual.

please light a small piece of it and smell the plastic if is abs, hi density pp or polyethylene or low density get same plastic from old container or pipe whatever and weld it, with very hot, big tipped solder gun, then ruff up and patch with JB epoxy! cut tiny cracks into small grooves i do mean small do not go thu body!

i was in plastics/fiberglass for 33 yrs or more. it will work! be sure tank totally dry inside and out clean area to be welded w/ acetone or alcohol first to assure good cohesion. oh yeah i 4 got ya da yada!
mike

Thanks for the two posts.

I will save these posts in case I need to make this repair.