"Peggie Hall" wrote


A failing/failed diaphragm wouldn't cause the pump to leak...it
creates an air leak in the pump ....

Ah, light dawns! It's harder to make things vacuum tight than pressure
tight and much, much, harder than watertight. Developing porosity in
the rubber would do exactly what you describe.

The sink drain "T" into the head intake line works great although
it means a lot of head pumping.

Most likely because the toilet is pulling air through the sink
that's preventing from priming. Put a plug in the sink when flushing
with sea water...when flushing with water from the sink, the sink
needs to be at least half full. Just running water down the sink
drain won't work 'cuz the toilet will pull more air than water.

No, it works perfectly in normal head mode. There is a valve in the
line from the sink to the head intake line.

What I meant by lots of head pumping was filling a 13 gallon holding
tank by pumping the head. I really shouldn't have posted that point
because it only applies to our very funky marina where there is no
water hose bib within reach of the pump out station. I tried filling
the holding tank by pumping fresh water through the system to avoid
motoring back to the dock to fill with the hose through the deck pump
out the way any normal person would. Now that I've done that once,
motoring back and redocking doesn't seem like as much work as it did
before

--

Roger Long

Although, if the pump diaphragm is starting to leak air on the back
stroke, wouldn't air bubbles or froth start to show up in the water
stream? I haven't seen any yet.

--

Roger Long

Roger Long wrote:
Although, if the pump diaphragm is starting to leak air on the back
stroke, wouldn't air bubbles or froth start to show up in the water
stream? I haven't seen any yet.

Nope...and you won't. 'Cuz it's not PULLING any air into the line, it's
just a slight air leak that breaks the prime.



--
Peggie
----------
Peggie Hall
Specializing in marine sanitation since 1987
Author "Get Rid of Boat Odors - A Guide To Marine Sanitation Systems and
Other Sources of Aggravation and Odor"
http://shop.sailboatowners.com/books...ku=90&cat=1304

Roger Long wrote:
The sink drain "T" into the head intake line works great although
it means a lot of head pumping.

What I meant by lots of head pumping was filling a 13 gallon holding
tank by pumping the head.

You--and most other boat owners too--need to learn to use the "dry" mode
to do more than pump the last of the water out of the bowl. Few people
realize that any manual toilet that's working anywhere near factory
specs can move bowl contents up to 6 linear feet (further if you get
some help from gravity, at least 4' vertically, in the dry mode. You can
cut your flush water by at least 50%, doubling the number of flushes
your tank can hold if you'll do this:

Pump only 2-3x in the wet mode to wet the bowl ahead of use...or add 2-3
cupfuls from the sink ahead of solids. Switch to dry. After use, pump
enough times in the dry mode to move the bowl contents to the
tank...then switch to wet only long enough to rinse the bowl...and back
to dry to push the rinse water through to the tank.

--
Peggie
----------
Peggie Hall
Specializing in marine sanitation since 1987
Author "Get Rid of Boat Odors - A Guide To Marine Sanitation Systems and
Other Sources of Aggravation and Odor"
http://shop.sailboatowners.com/books...ku=90&cat=1304

"Peggie Hall" wrote tank by pumping the head.

You--and most other boat owners too--need to learn to use the "dry"
mode

It does work and I use a variation of this method. The variation is
only because our Groco, at least, requires more wet strokes to move
paper to the bottom As soon as stuff is out of sight, I switch to
dry.

At the end of any weekend trip or day sail with lots of guests, I do a
long wet flush from empty to be sure the line is clear.

In view of the difficulty most guests have with the regular method,
even with printed instructions, I think I'll just put up with more
frequent trips to the pump out instead of trying to add another lever
sequence.

BTW tightening up that hose clamp has brought the water off pump
cycling of my fresh water pressure set down to only about once every
2 -3 hours. I can't fix the last little drip until I move the pump so
I can get at a metal joint on the tank that is weeping slightly but
it's quite livable. I'll do that when I install the accumulator tank
I bought yesterday.

--

Roger Long

"Roger Long" wrote in news:a1Bsg.19945$O35.10662
@twister.nyroc.rr.com:

A failing/failed diaphragm wouldn't cause the pump to leak...it
creates an air leak in the pump ....

Ah, light dawns! It's harder to make things vacuum tight than pressure
tight and much, much, harder than watertight. Developing porosity in
the rubber would do exactly what you describe.


The little rubber valves holding back the pressurized water from going back
into the supply tank also leak. They don't fill the bilge and nothing
leaks out of the pump as it goes back into the tank.

That damned buzzing of the pump coming on every 2 minutes for no apparent
reason while you're laying there thinking about all the things that can
sink the boat while you sleep just drives me crazy....trying to get to
sleep in the first place.

Same goes for the stupid electronic bilge pumps that come on to see if
something is there to pump all night....

"Why did that come on? I better get up and check, again."....and
again...and....nuts.