how to replace drain pipe glued in place

[LeonineThor]

I noticed my grey water was leaking/dripping at my first dumping this year. Upon inspection and removal of the valve I discovered there is a small crack in the pipe just upstream from the valve. But the whole section of the pipes are glued together. How the heck to I fix this? Picture shows me bracketing the section that I want to replace.

[Diemaster]

(on a dry pipe) i would try some flexseal or something like this:

https://www.amazon.com/Fernco-FPW248.../dp/B000JD6JVC

[rynosback]

Cut it out and re-plump with out leaks. And the good news is that it looks like you have room to work with.

[be happy]

I would cut the pipe that's against the wall just before it takes the 90. I would go to a big box store and get the correct pieces to make the repair.

[Long & Winding road]

I guess it depends on how aggressive you want to be. I used some flexable rubber tape that is removable later on down the road. Works great.

Found it at Home Depot in the super glue section. Its designed for pipes - you strech and wrap - sticks to its self great. And since this is not a pressurized line and its outside it might be worth a shot. I would never take a short cut on a pressured line inside the RV.

[javelin]

It looks like your coach uses the Lasalle Bristol dual rotating gate valve (picture attached) which includes the black and grey gate valves in one unit. This damage usually happens because many grey tanks are slow to drain completely and folks close the grey blade valve thinking the tank is empty when it is not. I find it better to leave the grey valve open over Winter (after initial draining – even when using pink antifreeze in the coach) and leave a tray under the 3” drain (uncapped) to catch any leftover grey water that may still drain over time. Black valve stays closed after draining and is usually not a problem (especially with pink antifreeze in the tank).
Doing an ABS pipe repair is possible, but tricky. If you have not done ABS plumbing before you may want to try the patching tape suggested by others (depending on where the crack is) or take the coach in for repair.
If the grey tank side of the gate valve is cracked (or it is glued to a cracked piece of ABS, only a new Bristol flange will fit......(valterra valve flanges will not work). So if you need just that 1 1/2” side part you probably will have to purchase the whole Bristol fitting (not hugely expensive but might be a little harder to find). The good part of that is you get new grey and black gate valves as spares. The hardest part of the ABS repair is that once glue is applied you have literally seconds to join the pipes in correct orientation and it is critical that the two halves of the grey side gate valve align or the gate valve itself can leak.

[javelin]

Just a followup on the Lasalle Bristol dual gate valve part number in my Jpeg....it may be something different now. Search ebay or some RV shops may even stock them. My links don't always work:



https://www.ebay.com/itm/Lasalle-Bri...gAAOSwHlRbq~FK

[Long & Winding road]

I repaired the black tank side right before it lead to the valve this spring. The factory used putty to join the two pipes together with a sleeve between them.... well that didnt last long (I thought it was a mistake or a short cut by Thor but someone here pointed out thats how they connect these large pipes together.... go figure).

I was going to take the valve out and clean it all up then glue together.... but was was barely leaking (like one drip a day while in my storage shed) so It just didnt seem worth it.

Then I was going to use a rubber coupler (with hose clamps) to connect the two side but my wife said "isnt there some sort of tape you can use"....well that trigged a light bulb so I went to HD and they had just want I needed. I actually used both the tape and then covered with rubber coupler but the tape fix it just fine.

I figured 5 or 7 years down the road (if I still have this RV) I might need to replace this valve and then I will fix or replace this black tank line.

So it all depend on how bad your leak is I guess.

Let us know how it turns out so others can learn from this.