Black tank cracked...twice.
Hi everyone. Haven't posted here in a while, so I hope this message finds you all well. I've run into a confusing situation with the black tank(s) on my 2018 Jayco Eagle 5th wheel. Last Fall 2022,...
Forum Discussion
I did some quick sleuthing on the InterTubes and at another forum (irv2.com), and think I can answer...
At one annual RV jamboree they have hundreds of vacuum pump-outs with no issues, so this is indeed an uncommon problem. But as Enblethen mentioned, the jamboree specifically warns people to manually block open the toilet flush valves. The roof vent may not suffice. The trucks also suck out subterranean cesspools and therefore can generate substantial vacuum to lift from depths. Some folks have reported tank damage from such service, and one guy reported damage to BOTH his wastewater tanks from a single service. Keeping the toilet flapper valve open and reducing vacuum on the truck can solve the problem. Some service techs were new and literally unfamiliar with the possibility of damage! A safer method is to gravity drain into a large, low bucket and have the tech insert his truck hose into the bucket, pulling from the bucket. More difficult, have the tech insert his hose into the end of your drain hose and suck from that. Or perhaps you could gravity drain into a large tote and have the tech pull from the tote, repeating that several times, closing and reopening the RV valve to help segregate that system from damage (or repeatedly removing the drain hose from the RV). Designed as a gravity drain system, RV wastewater systems aren't well suited to withstand either substantial pressure or vacuum.
At one annual RV jamboree they have hundreds of vacuum pump-outs with no issues, so this is indeed an uncommon problem. But as Enblethen mentioned, the jamboree specifically warns people to manually block open the toilet flush valves. The roof vent may not suffice. The trucks also suck out subterranean cesspools and therefore can generate substantial vacuum to lift from depths. Some folks have reported tank damage from such service, and one guy reported damage to BOTH his wastewater tanks from a single service. Keeping the toilet flapper valve open and reducing vacuum on the truck can solve the problem. Some service techs were new and literally unfamiliar with the possibility of damage! A safer method is to gravity drain into a large, low bucket and have the tech insert his truck hose into the bucket, pulling from the bucket. More difficult, have the tech insert his hose into the end of your drain hose and suck from that. Or perhaps you could gravity drain into a large tote and have the tech pull from the tote, repeating that several times, closing and reopening the RV valve to help segregate that system from damage (or repeatedly removing the drain hose from the RV). Designed as a gravity drain system, RV wastewater systems aren't well suited to withstand either substantial pressure or vacuum.
