Groco K rebuilt but problem

[garthpaine]

Hi everyone

I just finished rebuilding the Groco K forward head as it had the nasty recycling issue. I think the build went well and I expanded the rings so the piston is a good fit etc. It pumps well and does as expected. However when finished flushing, it very very slowly fills with water - I am guessing from the intake as the anti-syphon valve is whistling as it should and it has a new Jocker valve etc.

I am a bit confused as to which parts of the system stop the incoming water from entering the bowl when not pumped in and when the pedal is in the upright position (pulled up by the spring).

So I'd love some pointers as the why the water might be seeping in and where I may have made a mistake in the rebuild. Thanks in advance.

Cheers, Garth

[GordMay]

Model K Marine Toilets
The foot pedal water control allows the desired amount of flush water to be used and automatically shuts the water inlet off when the foot pedal is released.
The joker valve & vented loop prevents backfilling of waste discharge water.
A little food colouring, in a post waste flush 'clearing flush', will tell you which is filling your bowl.

For service assistance/information call 410.604.3800, and ask for [Patrick] the sanitation service department.

Installation, Operation, and Maintenance ➥ https://www.groco.net/media/file/file/k/-/k-series.pdf

OVERHAUL PROCEDURE
➥ https://www.groco.net/media/file/fil...let_repair.pdf

SLEEVE BEARING REPLACEMENT
➥ https://www.groco.net/media/file/fil...eplacement.pdf

Groco K Rebuild [Video] ➥ https://youtu.be/bXlqBlD6-aQ

[Bowdrie]

Originally Posted by garthpaine

I am a bit confused as to which parts of the system stop the incoming water from entering the bowl when not pumped in and when the pedal is in the upright position (pulled up by the spring).

Look on the exploded view of the parts.
The foot pedal shaft operates a cam, part #21, it has two little "arms", one arm is a stop, the other presses against the bronze pad that is fastened to the neoprene gasket, (part #26).
Over time the bronze "arm" on the cam can wear, and also the bronze "pad" on the gasket.
Should either or both have too much wear the gasket won't get pushed against its seat with enough force to seal.
Also, the little setscrew that holds the cam may have "lost its grip" on the shaft, and so the cam is not located in its proper position.

[markxengineerin]

I would close off your thru hull valve for the intake water between flushes (you do have a valve there, right ; ) ? That might be an easier debugging step than the food coloring.

When my Model K level rises, it's usually the joker valve being ever so slightly out of position. A few extra hard pumps clear out whatever was in there an all is usually back to normal.

[GordMay]

Originally Posted by markxengineerin

I would close off your thru hull valve for the intake water between flushes (you do have a valve there, right ; ) ? That might be an easier debugging step than the food coloring...

That would be too easy.

[garthpaine]

Hi everybody, thank you so much for your quick responses – there is an amazing depth of knowledge in this forum. I worked out that the pedal was hitting a drain bolt on the output elbow, and was able to re-adjust that so it clears, but I really need a stronger spring to keep the pedal closed. When the pedal is fully up, I don’t have a problem. Yay. I did turn the seacock off last night so that I didn’t wake up underwater :-) thanks so much, Garth