Groco Head Question

[firstbase]

Newbie to Groco manual heads (original on my 1987 Grand Banks 42' but rebuilt by Groco about 3 years ago) with an issue. I have my raw water intake closed and use fresh water from sink to flush. Forward head works fine. Do your thing, use pump handle to flush with fresh water. Bowl empties and continued pumping does nothing. Do the same thing in the rear head and it empties but then begins to pull in a little volume of nasty brown water with flecks of...?? which flows down from the rear top of the bowl. I assume from the raw water intake? Not very much, maybe a tablespoon or two per pump but enough to scum up the bowl.

Question is why would emptying the bowl by pumping be bringing in anything into the bowl? Again, forward head doesn't do this so something is up with the rear one. Something has to be off or leaking or something...?? Any comments appreciated!

 

[DavidM]

When you pump against a blocked raw water intake, you create a vacuum in that side of the pump, which can pull "stuff" past the piston and then push it into the toilet. The point is that the head's pump has two sides to the piston that goes up and down: one for the intake and one for the discharge. You are getting a little leakage between the two.

There are two solutions: rebuild the pump which may not last for long, or replace the head with one designed for fresh water. Don't just hook up fresh water to the head's intake. You might contaminate your fresh water source.

David

 

[HeadMistress]

Keeping the intake seaock closed isn't the culprit, although pumping dry can accelerate it. It's actually very common for older Model K toilets to start recirculating after 15-20 years 'cuz EVERYTHING, even a $1K bronze toilet pump, has a lifespan. The piston and the pump cylinder wall become so worn and out-of-round that that they allow bowl contents to recirculate, which is exactly what yours is doing.

But there is an affordable solution: you can replace just the "piston crank assembly" (part # K32) with the new version that has the grooves and seals. It won't last another 30 years, but should give you at least 5-6 years more. Price direct from Groco is very reasonable and if you've been able to rebuild the toilet once, it shouldn't be a difficult job. Patrick at Groco will be glad to walk you through it.
(410) 604-3800

 

[HopCar]

Which Groco toilet do you have?

Do I understand that you have a tee in your sink drain that lets you flush with fresh water from the sink? Close sink drain seacock, fill sink with fresh water, flush toilet by sucking water from the sink drain line, open seacock?

Do you flush the forward head the same way?

 

[firstbase]

Thanks for the comments. The heads are Groco Model K, hand operated. They were sent back to Groco about 3 years ago for rebuild.

To clarify, I don't have fresh water plumbed directly into the heads. We fill a large glass with fresh water from the faucet and pour it in the bowl by hand. How would flushing in this manner be different from using the foot pump to bring in raw water, stop, and then flush out with the handle? I believe that the foot pedal, when released, shuts off the raw water inlet. The hand pump then empties the bowl. How would pumping with the handle bring nasty raw water back in through the inlet? Simply the suction from flushing is enough to suck a little of what is in the raw water inlet/hose in past the inlet valve? That would be indicative of a failing inlet valve?

Thanks for putting up with my ignorance. I'm not much for tricking pieces of equipment to operate differently than designed but the previous owner flushed the heads this way. He claimed it was better to keep raw sea water out if at all possible. Less smell from dying sea critters.

 

[firstbase]

When you pump against a blocked raw water intake, you create a vacuum in that side of the pump, which can pull "stuff" past the piston and then push it into the toilet. The point is that the head's pump has two sides to the piston that goes up and down: one for the intake and one for the discharge. You are getting a little leakage between the two.

There are two solutions: rebuild the pump which may not last for long, or replace the head with one designed for fresh water. Don't just hook up fresh water to the head's intake. You might contaminate your fresh water source.

David

Thanks David. I think it's time to pull out the manual and read a little about how these work so I understand what you are saying. My problem not yours though!!!

 

[firstbase]

Thanks Peggie. They were rebuilt about 3 years ago and that doesn't seem like much time to have that happen? Not really sure...

 

[HeadMistress]

A rebuild only addresses the replaceable parts--seals, valves, gaskets etc. It doesn't replace the worn down bronze piston and pump cylinder walls...and over time any material, even bronze or steel, can be worn away, especially if the pump hasn't been kept scrupulously lubricated. It takes anywhere from 15-20 years, depending on the amount of use and how well the pump has been kept lubricated, for them to become worn out of round enough that the seals can no longer form a tight seal against the pump wall...allowing bowl contents to be pulled back into the pump to be recirculated. If you need proof, put a little red food coloring in clean water you add to the bowl and flush the toilet...you'll see red water coming out of the channel in the rim of the bowl.

These are $1K toilets, worth spending the money to replace the worn parts. Call Groco.

 

[firstbase]

A rebuild only addresses the replaceable parts--seals, valves, gaskets etc. It doesn't replace the worn down bronze piston and pump cylinder walls...and over time any material, even bronze or steel, can be worn away, especially if the pump hasn't been kept scrupulously lubricated. It takes anywhere from 15-20 years, depending on the amount of use and how well the pump has been kept lubricated, for them to become worn out of round enough that the seals can no longer form a tight seal against the pump wall...allowing bowl contents to be pulled back into the pump to be recirculated. If you need proof, put a little red food coloring in clean water you add to the bowl and flush the toilet...you'll see red water coming out of the channel in the rim of the bowl.

These are $1K toilets, worth spending the money to replace the worn parts. Call Groco.

Thanks Peggie, will do. I assume that this issue is a contributing factor to the odor issue onboard? Not too bad but enough to know something is going on. Little more than what I remember from past boats (years ago).

 

[HeadMistress]

I assume that this issue is a contributing factor to the odor issue onboard? Not too bad but enough to know something is going on.

Unlikely unless the odor is emanating from the toilet bowl while flushing. I need to know a lot more about the nature of your odor(s) (different sources have unique characteristics) and where it seems to be most noticeable. If you click on the link in my signature you'll find information there that should help you identify and eliminate it. And I'll be glad to provide any additional help you need...just send me a private message any time.