Black tank dump plumbing replacement?

[gkainz]

My kids got a used RV and on their maiden trip discovered the black tank dump plumbing leaks. Appears to have one or more cracks in the plumbing from the tank to the dump valve. They tried to patch it with flexseal to get them through the weekend but didn't stop the stinky drips.

Taking a quick look at the dump plumbing, it appears to be a series of 3 or 4 elbows from tank to dump valve with little to no pipe sections that could be cut and new elbows glued up to replace the cracked section(s).

How does the first fitting secure into the black tank? I didn't notice any flexible type seal or joint and a hose clamp, but again, was just a quick look, not a close inspection. My fear is that this first fitting is glued into the tank outlet?

Thanks for any suggestions! I intend to manage this repair and give my son-in-law instructions from a safe distance 🙂

[schlep1967]

jdc1 wrote:
If you're trying to get the glues ABS sections apart, in the construction trades we use a small grinder with a diamond blade. We cut the overlapping section just deep enough to touch the inserted part. Make 5-6 cuts. Then use a small (1/2") chisel to remove the overlapped ABS fitting. Sand down the lefy over particles, then start glueing the new parts in place. Be sure to use glue on both male and female parts.

For the price of new fittings, I ain't working that hard. I had to replace about half of my system last week after a blow-out tore of the end piece. Cost including a container of the proper glue ($7) and tape for the underbelly ($6) was right at $30.
Now if you can't find the correct replacement parts, different story. Time to do the work.

[jdc1]

If you're trying to get the glued ABS sections apart, in the construction trades we use a small grinder with a diamond blade. We cut the overlapping section just deep enough to touch the inserted part. Make 5-6 cuts. Then use a small (1/2") chisel to remove the overlapped ABS fitting. Sand down the left over particles/glue, then start glueing the new parts in place. Be sure to use glue on both male and female parts. It's a pain working on your back, but it's a lot cheaper than having someone do something this simple.

[schlep1967]

gkainz wrote:

schlep1967 wrote:
They can do it any number of ways. Mine has the valve right at the tank. On thing to consider is the use of a fernco coupling (google it). If he can cut right before the leak at the end of an elbow and use a fernco to attach to the new piece he should be fine.

Thanks - will look into that. My rig also has cable pull dump valves right at the tanks. I was thinking about suggesting that improvement for him, as well as combining black and grey plumbing into 1 dump valve and connector - his rig has separate dump hose connectors and separate dump valves for black and grey tanks, with the generator installed between them.

For simplicity of repairs, I think we're going to stick with just replacing the leaking parts.

Plumbing the two dump hose connectors together is fine but you want to keep separate valves. Otherwise you essentially only have one big combined tank. Better separate so he can drain black and then flush the hose with grey.

[gkainz]

schlep1967 wrote:
They can do it any number of ways. Mine has the valve right at the tank. On thing to consider is the use of a fernco coupling (google it). If he can cut right before the leak at the end of an elbow and use a fernco to attach to the new piece he should be fine.

Thanks - will look into that. My rig also has cable pull dump valves right at the tanks. I was thinking about suggesting that improvement for him, as well as combining black and grey plumbing into 1 dump valve and connector - his rig has separate dump hose connectors and separate dump valves for black and grey tanks, with the generator installed between them.

For simplicity of repairs, I think we're going to stick with just replacing the leaking parts.

[schlep1967]

They can do it any number of ways. Mine has the valve right at the tank. On thing to consider is the use of a fernco coupling (google it). If he can cut right before the leak at the end of an elbow and use a fernco to attach to the new piece he should be fine.