Re: Black Tank Valve Leak Reply #20 – April 01, 2019, 10:38:42 am Quote from: bbeane – March 31, 2019, 04:16:56 pmMe thinks that with the pressure of a full tank above the valve, a bad stem seal is going to leak regardless of its orientation.Maybe the stem seal never sees liquid until the valve is opened. Just a thought. Quote Selected
Re: Black Tank Valve Leak Reply #21 – April 01, 2019, 11:25:55 am Quote from: craneman – April 01, 2019, 10:38:42 amMaybe the stem seal never sees liquid until the valve is opened. Just a thought.There isn't any "stem seal" on the rod that pulls the valve gate open. There is only a molded plastic guide in the top of the valve housing. The plastic guide is not meant to be water tight. I posted a link (in another thread) to a Airstream forum thread where the OP cut the top off a Valterra dump valve. The operating rod goes through the plastic guide, and then connects to a slot in the top of the sliding "gate". This connection slot is located outside of the round rubber seals on both sides of the sliding gate. If any waste water gets past the round rubber gate seals, it could run freely out of the top of the valve.AFAIK, the orientation of the valve - horizontal or vertical or whatever - would have no bearing on this type of rubber seal leak.See the link below for excellent photos of the gate valve construction:Waste valve handle and rod pulled out of the valve - Airstream Forums Quote Selected
Re: Black Tank Valve Leak Reply #22 – April 01, 2019, 11:42:02 am Thanks for the link Chuck. Good info for when a bad day comes. Quote Selected
Re: Black Tank Valve Leak Reply #23 – April 04, 2019, 01:21:18 pm I was going to say that coating the valve stem with silicon grease would be a good idea. However, perhaps after moving the valve several times to coat the valve guide, the valve stem should be wiped to may eliminate the problem of dust contamination.Eventually, poop water will leak past the valve stem guide, but proper maintenance will help extend it's life. Quote Selected
Re: Black Tank Valve Leak Reply #24 – April 04, 2019, 01:25:26 pm Tim,I don't see dust contamination as an issue, as the valve is closed (stem inside the valve) except when dumping. And, if permanently set up and gray valve open (which we don't do), wiping off the stem before closing would be easy. Quote Selected
Topic: Black Tank Valve Leak