Cistern won't stop filling

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May 9, 2003
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Fayetteville, NC
So, when I flush the toilet, it starts filling the cistern like normal, but doesn't STOP when it reaches top level. Doesn't overflow but i hear water still running, (into the commode?). I have to lift (slight nudge upwards) the floating rubber ball thingy by hand (the last few millimeters) so that the filling stops. in other words, the floating rubber ball thingy doesn't fully return to the top most position when water fills in the cistern. Very annoying - any easy fix for this? I guess it's called the float ball in this pic. is the float rod part too tight? there are two screws there... One on the inlet tube where the rod connects, the other a little further ON the rod itself... shall I loosen one of them? Thanks for any help/advice.
 
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i had the same issue in 4 of our toilets, all at once, the rubber made "piston" from this diagram of yours, it seems the rubber isn't pliable anymore and doesn't shut off the water from coming in and hence the water keeps filling up. I replaced those and the problem was fixed, its a pretty cheap part, I dunno what it is called by my uncle is a master plumber and he bought em.
 

97tbird

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Originally Posted By: Pop_Rivit
Bend the float rod a little to force the valve to shut off a bit earlier.
in what direction? downwards or upwards? (I assume up?) Thanks!
 
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Illinois
There should be a screw on the top of the inlet valve. Turn that screw clockwise slowly until the flow of water stops. If the inlet valve does not have a screw then you would bend the arm down not up.
 
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Southeastern, PA
In the diagram you posted the siphon serves as an overflow. If the tank gets too full (for example, the inlet valve fails open) the siphon allows the water to overflow into the toilet bowl and down the drain. Without the siphon, the tank would overflow onto the bathroom floor and cause a lot of damage. There's also (not shown) usually a small tube from the fill valve into the siphon that serves to refill the toilet bowl after the flush. Sometimes the fill valve shutoff goes out of adjustment and it is essentially trying to fill the tank above the level of the siphon. Which sounds like what you described.
 

97tbird

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Originally Posted By: wymi516
There should be a screw on the top of the inlet valve. Turn that screw clockwise slowly until the flow of water stops. If the inlet valve does not have a screw then you would bend the arm down not up.
OK. There is a screw on top of inlet valve. I did turn that screw yesterday but COUNTER clockwise -LOL! (I tightened it, didn't I?) probably made it worse. Will do clockwise and report back.
 
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Fort Lauderdale, FL
The name of that assembly is the ballcock. Seriously. Adjust the screw (screw your ballcock both ways) until water shuts off, or grab the rod (of your ballcock) and bend it down. Your ballcock shouldn't be so leaky after giving your rod a good bending with your hand. Alternatively, if your current ballcock is still having performance issues, you can go to the HD or Lowes and get a new adjustable ballcock that will satisfy, and for a cheap price. A new ballcock is easy to install, just try not to gt everything wet while you're handling that. Just make sure you get the proper length.
 

97tbird

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Ballcock! Had to write it at least once. Thanks guys! Turned the screw clockwise, and first trial went ok. But it was intermittent to start with so, too soon to tell. Will keep monitoring progress.
 
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If you do need a new ballcock, don't go crazy getting off the old ballcock. The Mrs. may not be too happy if you have to pop out halfway through the job!
 
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British Columbia, Canada
3 steps, in order: try adjusting the screw try bending the float rod (bend float down, make the tank think it's really full) replace the inlet valve. This happens often enough that I keep a spare inlet valve (all 3 toilets are the same) with my plumbing tools.
 
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Also, avoid the "all in one" this'll-fix-your-toilet kits with the slidy float that's on a vertical rail. These take forever to refill the tank, compared to OE. This makes it take longer after a "courtesy flush" to repeat business.
 
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Originally Posted By: ecotourist
3 steps, in order: try adjusting the screw try bending the float rod (bend float down, make the tank think it's really full) replace the inlet valve. This happens often enough that I keep a spare inlet valve (all 3 toilets are the same) with my plumbing tools.
This.
 
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