I (literally) just went through this last week with my 31L5. In my case, the 1-1/2” slip nut that was attached to the waterless p-trap cracked, and I had a massive leak that made the shower non-usable. Note that this is discussed in another thread, and some pictures of the problem are posted:
https://www.forestriverforums.com/fo...ml#post2819551
I tried as hard as I could to fix the problem myself, but I just couldn’t get my arm into the access hole far enough without getting all cut up on the fiberglass chards hanging under the shower. I bought this part at Lowe’s:
https://www.lowes.com/pd/Road-Home-2...ing/1002751746
The trick is to get in there with a cutting tool to cut the old fitting off and then using a rubber coupling to connect the existing drainpipe to the adapter referenced above. I just couldn’t get enough working space. I considered cutting another access hole next to the original one so that I could get 2 hands in there, but ultimately gave up and returned the parts to Lowe’s.
I called a mobile RV repair service, and they showed up with EXACTLY the same parts I had just returned! The original plan was to cut a second access hole, but the repair guy had very small arms and was able to cut the old pipe fitting off using just a hacksaw blade he held in his hand (no holder – just the blade). So, no second access hole was needed, although he did cut his arm up pretty well in the process. He then used the rubber coupler to attach the new adapter to the existing waterless p-trap. From start to finish it took him 45 minutes. The total bill came to $326.92 (including about $13.00 in parts). This included a $100 service call just to get them out there, $60 for a “diagnostic fee”, parts, and 1 hour labor. Pricey, of course, for a relatively simple fix, but at 69 years-old, I try not to sweat the small stuff and am now back to enjoying my 31L5 shower.