2024 2500RL black tank flush leak

[sbk12rs]

Hi All , Second trip out this weekend and as the title suggests , there’ seems to be a leak when I use the black tank flush .I was flushing and my wife found water in the bathroom on the floor at the same time I noticed water leaking from the underside in a couple spots . I have not yet taken apart anything to investigate . Seems to be under the bathroom sink .

[Cate&Rob]

Up high under the sink, you will likely find a black plastic device plumbed with black hose. This is the flush line vacuum break. It is normal for this device to leak a small amount of water when the flush line is first pressurized . . . but, not enough to spread water on the bathroom floor. Find this device and observe it while flushing the tank to determine if the vacuum break itself is leaking or perhaps a connection to it.

Rob

[sbk12rs]

Hi , I was just about to look for make an air pressure line to use air instead of water . Are you talking about the backflow preventer ?

[howson]

Hi , I was just about to look for make an air pressure line to use air instead of water . Are you talking about the backflow preventer ?

It's a vacuum break valve. Rob (and others) have detailed information with pics and descriptions here: https://gdrvowners.com/forum/operati...ack-tank-flush

Howard

[sbk12rs]

I found the line and valve . It’s tucked up tight under the counter top behind the sink . Whatever water that was residual is gone by simple touch around the valve . I need a little more time to spend on it to investigate more and I ordered a winterizer air hose to check with air instead of hooking water back to it . At that point , I’ll remove actual hose connection at the camper to see if how “it’s “ connection to the actual hose to the valve is not leaking there .

[JBill9694]

sbk12rs, trace the piping from the vacuum break you found under the sink, if it is plumbed into the drain line for sink then this is the vacuum break for the sink drain line, not the black tank flush, and you hunt will continue. The vacuum break you're looking for could in a wall cavity with no access. No, I don't know why GD would do this.

[sbk12rs]

I put about 10/15 pounds of air through the line and there seems to be a leak around the vac break that I can feel and hear . I can hear air running to the tank as well . There must be residual water in there as I can hear it gurgling.

[sbk12rs]

The line has a clip securing it to the wall up tight to the underside of the countertop . I’ll need to do a little more investigating by removing the screw and taking another listen .
If it’s the vacuum Break leak or a simple tightening of the lines ( hopefully ) would air still bleed through the Break if it was working as it should ?

[Cate&Rob]

sbk12rs Water pressure closes the vacuum break . . . I "think" air pressure would do the same, but I am not sure. The waterline connections to the vacuum break will be hand tightened threaded connections with a cone washer seal inside. First thing to try is tightening these to see if the leak stops. Second thing to try is undoing these connections and examining/replacing the cone seals. Last step would be a new vacuum break. Note that the correct RV part is a vacuum break with a check valve on the tank side.

Rob