Water getting to the black water tank

[Raider]

Hello,
New to the forum and new to class C motor homes. I recently purchased a 1985 Jayco 26 Jayco mini. It has not been used since last year and was still winterized. Today my father and I started getting all the systems ready to use. We hooked up city water to flush the systems. Soon after I discovered a leak on the black water tank? The tank had a leak at the flange from the drain tube at the tank. When I looked at it I discovered a massive epoxy repair at the drain pipe to tank interface. That was a surprise, I was checking grey water systems and find I am getting water in the black water tank? Is this normal? We did not flush the toilet before the leak. We traced all the grey water lines to no avail. Looking under the camper I could not see any lines that someone ran to the sewage tank.
Your thoughts would be very much appreciated.
Thanks
Greg

[Grumpy]

Years ago there was a theory to add the grey water from the bathroom sink and/or the shower to the black tank to help flush it out when dumping. That is no longer the norm and it may be against the RVIA plumbing code today.

[Raider]

Yes I have read that. These are 2 separate systems that should not be connected together. I tried to look for that but did not discover anything obvious. My thoughts were maybe Jayco had tied the systems together back then for flushing purposes. I am thinking the previous owner might have read about the idea and then did it. Not good now I have to figure what out what he did.
Thanks for your response.
Regards, Greg

[need-a-vacation]

From what Grumpy posted, it doesn't sound like the 2 holding tanks are/were tied together, just that the bathroom sink or shower drained directly into the black tank, unless I misread his post.

I know our outdoor kitchen sink drains into the black tank. One thing I wish was different on our Jayco. Last trailer had 2-30g gray tanks, one for the kitchen sink, one for the bathroom sink/shower. BUT it's not enough to want a different trailer!!!

[Grumpy]

Originally Posted by need-a-vacation

From what Grumpy posted, it doesn't sound like the 2 holding tanks are/were tied together, just that the bathroom sink or shower drained directly into the black tank,

Yep, exactlly....

[Raider]

That makes more sense.
Thanks again
Greg

[Raider]

The 1985 Jayco 26 mini bathroom sink does drain to the black water tank along with the toilet.
Thanks for the help,
Regards
Greg

[TX_Arvee]

Not saying I have ever done it by accident, but if you open both tank valves to dump at the same time the one with the most in it can force into the other tank. "I heard" it is unpleasant and requires a lot of flushing of the grey tank to get the ugliness out of it...
;-)