WC Skipper - "DRY" pump (pedal up) not working

[pma_foyl]

I recently rebuilt my WC Skipper (every replaceable part) and it is pushing water through very well, with pedal depressed and pumping. But it is acting strangely when trying to pump OUT the water (pedal not depressed) in dry mode.

After pumping with the pedal depressed (which does seem harder than before), there is some vacuum (bubbling) AND when I try to pump dry, water continues to come in (tho much less). It doesn't allow for completely emptying the bowl.

Could this be an in-take valve thing? Output valve??? Or ?????

Any assistance would be appreciated.

[peghall]

Is it an original WC Skipper or the Thetford "Skipper II?"
Regardless of which one it is...where did you find the parts to rebuild it?
Parts for the two versions are not interchangeable.


--Peggie

[Bowdrie]

Look at this exploded parts diagram and identify part #14.
Each of the two rubber flap valves have a bronze washer/plate on them, the washer/plates are on opposite sides.
That part can be installed backwards, be careful to install that part correctly.
Exploded diagram.
https://marinesan.com/tecma-thetford...parts-drawing/
Inlet flapper valve.

https://marinesan.com/inlet-flapper-skipper/