[C320-list] Head backing up

[Graeme Clark]

Your joker valve needs replacing.  This is the one way valve at the base of the pump where it enters the waste pipe.  It may have just got a piece of “debris” stuck in it that prevents it sealing properly or it may have lost its elasticity or perished.

It’s a very cheap quick and simple repair and not too messy, but rather smelly!

If there is significant backpressure (ie holding tank is pressurising due to blocked vent) it can invert but you’d know that because it’s then almost impossible to pump out!

Graeme



Sent from my iPad

> On 20 Aug 2020, at 05:11, David Veeneman <davidv at veeneman.com> wrote:
> 
> I have recently noticed a Robles with the Jabsco head on Adelante. After I pump the bowl dry, the system backs up a bit, and fifteen minutes or so later, the bowl is about 2/3 full of liquid waste.
> 
> This happens when I am using the holding tank. I pump the bowl dry, lock the handle, and leave the pump lever in the ‘pump dry’ position. Until recently, when I pumped the bowl dry, it stayed dry.
> 
> Any thoughts as to what might be going on? Thanks.
> 
> —
> David Veeneman
> SV Adelante, Hull#131
> Dana Point, CA