Dry bowl

[Sandero]

I've recently completely rebuilt my Groco KH head, no old seals or rubber parts remain, everything has been totally cleaned and then the whole thing repainted. I've got a vented loop for the discharge

I've notice that with the sea cocks open water slowly seeps back into the bowl. This can only from two sources; the inlet water, or water come back passing the new joker valve. If I close the inlet seacock since water seeps in it must be the joker. Have I installed it incorrectly or perhaps over tightened or distorted it some how? I recall that this was not always the case in the past and the seeping seemed to be associated with a cruded up joker valve.

I don't think more than the water up to the vented loop can return to the bowl. Does anyone know why this is happening?

[Pblais]

The joker valve it what lets water in and at the same time keeps it out. Assuming it's one of those heads that has a lever for dry and flush you need to be in the dry position such as when pump out the waste / water. Leaving the lever in wet / flush might let small amounts leak back in. If the seals are new they should do the job.

The vented loop will protect you from water siphoning into the boat and sinking. If you think about it if it didn't the failure of a stupid rubber flap could sink you. At most you would have just a little back flow from the water level of the loop in the head side of the vent. At worst the level in the bowl will rise to match that level. A long or higher than required loop could back flow more than a short one. If you flush with enough water you should never see waste coming back. that would be a vent problem in the loop. The vent in the loop and the tank both need to work properly else you can have problems. The vent in the loop lets air in and the vent in the tank lets gas (usually CO2) out.

[cabo_sailor]

I can't say for certain on your Groco. On the Raritan there are two bolts that hold the flange that positions the joker valve. I had a noxious problem with the last bit in the waste hose slowly seeping back into the bowl. According to Peggy Hall, the "headmistress", if the bolts were overtightened they distorted the joker valve enough to let "water" seep back past the joker valve.

The last time I rebuilt the head I was extremely careful to alternately tighten each bolt as evenly as possible. Nor did I really torque them all that much. With many smiles, , I can report no back seepage.

Short of a whole new head which may or may not solve the problem (probably not), I can only report my own small success. Of course I dread the next time it is time to re-build and can only hope I do it right again. At the very least, in the case of my Raritan, I know what the problem is. According to Waldo in Robert Heinlein's novel, knowing the problem is 90% of the solution.

[Sandero]

I am not getting waste back in, but I could only determine that if I didn't do a through flush and left some black water in the effluent hose just down stream from the joker. Haven't done that. I suspect cabo may be on to something and the joker cab distort and allow bleeding back.

The problem is how to know how to tighten down the flange that holds it in place to NOT cause any distortion. If I assume it's over tightened, perhaps I need to slowly slack off the nut and see if the back flow problem abates.

It's definitely unrelated to the pump out lever since there is in no flush or dry bowl setting. I'll call Groco and see what those geniuses have to say.

[GordMay]

Have you looked at the Groco “KH” Service Manual ?
Goto: Untitled Document

ie:
"Note: Once the bowl has been cleared, pump an additional 5 strokes to clear the toilet discharge arm and joker valve."