wife says “fix the embarrassing toilet!” before the holidays.

I have an American Standard Toilet that is that same age as my house, about 18 years old. When the toilet refills the tank after a flush, the noise of the water going in is unbearably loud and to make matters worse, very slow. It can take a full 90 seconds to refill at full supply. I mean the sound is very loud, you can hear it across the house even with the bathroom door shut. I have lived in the house about six years and the issue is about the same as when I moved in. This half bath toilet is near the hearth room off a kitchen and is used by guests….and the wife says “fix the embarrassing toilet!” before the holiday guests arrive.

I think I hear two different noise pitches, with one coming from near the supply line and the other in the tank via the water filling. I have replaced the supply line and the supply line valve shut-off thinking they were clogged or something. I have bleed the lines throughout the house thinking it might be air in the line. No help. I can change the pitch of one of the noises by turning and playing with the supply line cut-off valve to reduce the amount of water coming in slightly, but that only slows the refill down and barley results in a less audible sound.

So...

Is this a bad toilet,
too small of supply line (3/8),
bad fill valve
or god forbid a bigger whole house plumbing issue?

The other four toilets in the house are slow to refill, but not nearly as loud. My wife can deal with slow, but not the noise. Help.

Any suggestions?

I think my next move would be to replace the fill valve.

A toilet that old uses 5-6 gallons per flush. It might be time for a new one. But, for less than $10 or so, you can replace the fill valve. Normally, this is fairly quick and easy. The two more readily available valves are Fluidmaster 400A (?) or Korky Quietfill.

Are your pipes galvanized? That all in itself could be a problem since they rust from the inside out while dumping rust particles into the seals and clogging things up.

The house has all copper piping until you get to the toilet's cutt-off valve. It is stainless steel and so is the rigid supply supply line to the toilet.

Hmm? Korky Quietfill, I wonder who supply's that.

I doubt it is stainless steel.

They are chrome plated brass and copper.

The 400A and Korky work very well. Use a braded stainless supply line and replace the stop also if you can, they make nice 1/4 turn stop valves now, no more turning tighter and tighter to stop the flow.

FWIW, the Korky Quietfill valves can be purchased at Lowe's. Highly recommend. They seem to be able to take quite a bit of grit & junk in the water before fouling. They are also very easy to take apart, clean, and if necessary, individual pieces of it can be replaced without having to throw out the whole valve. Seems to be a better design than the typical Fluidmaster ones.

Also, the Korky Quietfill is was Toto toilets ship with from the factory.