Tank leak...bad flapper?

[Dave Stone]

My sister's 2-piece toilet "runs" at intervals, indicating a leak from the tank to the bowl (no sign of exterior leak). I replaced the flapper with a new one and all seemed well, but she says the leak hasn't stopped. She says applying downward pressure on the new flapper (using her hand) stops the leak.

Did I buy a bad flapper (Certain Seal, #400)? It was identical to the original, and the gasket looked OK, but so did the gasket on the one I replaced. There is slack in the chain when the flapper is seated.

The seat on the flush valve looked OK and had no visible build-up of crud and felt smooth to my finger.

Can flush-valve seats warp over time? The toilet (1.6 gal/flush) is, I think, at least 15 years old. Is it time to replace the flush valve?

Is there another way the flush valve can leak into the bowl that might be stopped with hand pressure on the flapper? As you can tell, I'm a little unclear about the structure of the valve and its gaskets.

Thanks.

Dave

 

[CountryBumkin]

There could be a buildup (calcium or such) on the seat. Try rubbing a scouring pad around the seat area. It should feel smooth.

 

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[Reach4]

Checking for debris on the seat is good, but I would probably use a cloth than a scouring pad.

I would probably try a new flapper. It is a lot easier than replacing or repairing a flush valve. Some flappers are softer and more conforming than others. http://m.korky.com/landing.php would help identify one that I would try.

This is non-standard: I would put a very thin coat of silicone plumber's grease where the flapper contacts the seat. I am not a pro, and I have a big tube of silicone grease. So I tend to see that as a possible solution. It won't hurt-- other than your pocketbook.

 

[Dave Stone]

There could be a buildup (calcium or such) on the seat. Try rubbing a scouring pad around the seat area. It should feel smooth.

No evidence of crud on the seat and it felt smooth, but the scouring pad is worth a try. Thanks.

 

[Dave Stone]

Checking for debris on the seat is good, but I would probably use a cloth than a scouring pad.

I would probably try a new flapper. It is a lot easier than replacing or repairing a flush valve. Some flappers are softer and more conforming than others. http://m.korky.com/landing.php would help identify one that I would try.

This is non-standard: I would put a very thin coat of silicone plumber's grease where the flapper contacts the seat. I am not a pro, and I have a big tube of silicone grease. So I tend to see that as a possible solution. It won't hurt-- other than your pocketbook.

Thanks; sil. grease is an interesting idea. Yeh, I'll be careful with the seat. "Scouring" wouldn't mean steel wool. A softer more flexible flapper may be the answer. The current one is hard plastic and its seal is very thin.

 

[Jadnashua]

Some of the flapper valves have both ears to attach to the nubs on the sides of the overflow tube, and a ring that fits around the tube to hold it in place. IF yours has nubs, AND you also used the ring, take it back off, cut the ring out, and ONLY use the nubs to attach it. If it only has the ring, you might need to be more careful in centering it properly. If the seal between the flush valve and the tank is loose,it could leak out underneath the flush valve, and most of the time, it would end up in the bowl, so there'd be no external leaks.

The other thing is either too much or not enough slack in the chain. Too little (should be a couple of links of slack) and it can be slightly held up off of the seat, too much, and it might get hung up or caught under the lip. Pressing down would overcome the tension of the chain from being too short (the rubber would stretch). Depending on packaging and how things were stored, the flapper could have warped, and won't seal well. The water pressure might eventually straighten it out, but not necessarily...the rim should be nice and flat all the way around.

 

[Dave Stone]

Thanks, Jim--much appreciated. Chain is OK, no ring on the flapper, and it's attached via nubs. I bought another flapper made of flexible rubber instead of hard plastic. After arriving at the toilet, it was not detectably leaking over a 30-minute test period (I used a dye tablet and also marked the water line with a pencil), let alone at the considerable rate that had been claimed. I installed the rubber flapper anyway.