Jabasco pump shaft still leaking

[VicS]

There is no vented anti syphon at the top of the loop ..........

There is not a lot of point in having the loop if it is not vented!

Note that the vented inlet loop should be between the pump and the bowl. If its between the seacock and the pump then air will be sucked in through the vent when attempting to flush.

Maybe your loop is in the wrong position and the vent valve has been removed/omitted to enable the flush to work ????

 

[RichardS]

Thanks. I do close the seacocks when not on board. It is a good point. Perhaps I will leave the switch in the left "open" position in this situation.

That's what I do although the top of my toilets are above the water line so syphoning is not an issue.

After a really good pump through I also release the handle "twist and lock" mechanism when I leave the boat with the seacocks closed as that relieves the pressure on the lower flap valve which might eventually deform it and stop it working so effectively.

Richard

 

[stu9000]

There is not a lot of point in having the loop if it is not vented!

Note that the vented inlet loop should be between the pump and the bowl. If its between the seacock and the pump then air will be sucked in through the vent when attempting to flush.

Maybe your loop is in the wrong position and the vent valve has been removed/omitted to enable the flush to work ????

Hmm. I think your description fits what i see in this diagram

My set up looks the same as my grandparents ol macwester. I dont think it has been improperly fitted. It is just an old design.
The large exit pipe loops but the fresh water feed takes a more direct route.

I assumed the loop worked in a similar way as the exhaust swan neck to reduce the risk of syphoning, even without a vent.
It must also be done to reduce the likelihood of boats sinking from failures of the seal at the toilet end of the pipe.

Im still getting to know the boat but I cant see a bilge keeler being at serious risk of syphoning so fitting a vent it isnt top of my list of jobs.
But the ol girl and I are still getting to know each other so we will see.

Cheers

S