On my 1989 Island Packet
35, the Forespar vented loop valve (duck bill style) leaks
liquid when pumping out my Jabsco
. Enough to create a 6-8" wet spot on a paper towel laid across the valve. The particular vented loop is between my head
and the holding tank
. The vent also makes a squealing noise
when pumping (air escaping?). I've removed the valve and cleaned it without success. I then replaced it and still have the same issue. Additionaly, I get a small amount of back flow into the bowl (head has not been rebuilt in several years).
Something is causing elevated pressure in the line. While the dirt daubers love to clog my holding tank
vent line, I still get the problem after insuring the tank vent line is clear and opening the deck
pump out cap to relieve any potential tank pressure. I am able to pump my tank without issues. The only other item between the head and holding tank is a Whale diverter valve, which allows over board discharge when in an approved area.
Thoughts? I'm thinking a restriction of some sort since the bowl contents will make it to the head. Any issue plugging the old cap with epoxy
to seal the vent while docked? (short term fix)?