View Full Version : How to replace black water tank ?

02-15-2017, 09:01 PM
We suspected a leak and sure thing, it has to go. But we are a bit perplexed on how it comes out. I would appreciate help from those who dared to do it themselves. We do know its a center-drain tank and its black, and it is not ABS plastic. Do we drop the tank and how is it secured in there - to take it apart ? I see the vent pipe and the toilet pipe that needs cut to detatch there, where is the tank flush connected ? Ok thanks

02-15-2017, 09:27 PM
Not knowing what trailer you have--and even then, might not know its layout. But, locating the tank and uncovering all sides will be a lot of the battle. Most tanks are barely supported by angle iron along the long sides and may have a cross brace.
Why not get the tank completely clean and try some of the liquid fixes--JB Weld is one that should work if you get the right epoxy for the plastic.
Other than that, you will just have to learn as you go...
Wish you good luck.
And, welcome to the forum.

02-15-2017, 11:28 PM
Thanks for the reply. I found this :

Replacing a RV Waste water tank - Black or Grey Water
icondirect-com icondirect-com

April 10, 2014
Having to replace an original holding tank can seem like a huge task, but for the 'Do it yourself' minded - it can often be a lot simpler than first thought. Here's how it goes:

You'll want to measure out your original tank (and any extra area that would allow you to upgrade to a larger tank) to allow you to find an appropriate replacement. Planning out and 'mapping' your plumbing is also part of this initial step. Make note of drain location on the original tank and any extra fittings/components that you may require to hook up the new tank.
HT175 Black Water Holding Tank
HT175BED - Example Replacement Holding Tank
Find a replacement. Comparing by dimensions, you'll want to locate one that will fit in the area measured in step 1. You'll also want to consider how you will be mounting the tank. Replacements have a 1.25" flange for mounting with brackets or screws, so ensure you'll have room for whichever method.
Remove your old tank if you haven't already. Typically it involves removal of some screws and/or sliding the tank out of "L" type brackets. You may need to cut out some plumbing fittings and pull out some of the pipes to help configure the new tank.
Figure out where to install the intakes on the new tank by putting it into place temporarily and marking where the inputs should be cut. Precision is important here - measure/mark twice, cut once!
Pull the holding tank back out and use a cup saw to drill the input holes. There is usually one input (2" fitting or 3" fitting) and a vent (1.5" fitting) in most configurations. Install the fitting using an ABS Glue and allow time to cure.
3" Threaded Fitting For Holding Tank
3" Threaded Fitting
While the tank is curing prepare all input plumbing to be installed in the tank (appropriate fittings, make sure they are cleaned and make certain you have glue ready).
Place the tank back in & secure. Ensure the tank is lined up with all inputs. Use straps or banding to provide additional support to the belly of the tank.
Connect all inputs with the appropriate fittings & glue. You're done!

Tags: rvwaste tankholding tankrv repairblack watergrey waterabs tanksfittings

02-15-2017, 11:41 PM
I guess we do have ABS, it s the black ones. I got it mixed up. Anyway, thanks for your imput. If the source of the problem is small, surely will look into j.b.weld.how well does that hold in extreme temperatures ?-- we're fulltimers in a keystone Everest a 2005. Love this Rv and trying aftermarket upgrades now.

02-16-2017, 09:02 AM
JB Weld is excellent for permanent repairs--has been in use for many years for problems such as yours. Tank just has to be clean/dry and the leak area accessible. I certainly would try this approach before replacing the tank.