After flushing, my toilet continues to make a leaking sound. I have figured out that the reservoir is leaking into the toilet bowl. After replacing the flapper and seal, the noise continued. I noticed that after the bowl is full, the water is still slowly running from the small tube that is connected from the "fill valve" and drains into the tank overflow assembly. Please note that I have manually pulled the leveling device or rubber ball slightly upward to see if that would stop the flow, but that hasn't worked.

Is there an easy fix to this problem or should I just replace the entire "fill valve"

Sorry if my technical references are wrong, but hopefully I explained it enough for you to understand.

Your advice would be greatly appreciated.

OK if you pulled up on the ball and it still leaked then you can replace the seal in the old ballcock for about $2 and 20 minutes of work. You can replace the entire ballcock for under $10 and about 25 minutes labor. Its up to you and your skills, neither job is difficult but replacing seal requires you to understand how you particular ballcock is constructed. Describe it to us and I'll bet someone here will tell you the name and model.

The fill tube in the overflow must be above the level of the water in the tank to prevent syphoning.

I noticed that after the bowl is full, the water is still slowly running from the small tube that is connected from the "fill valve" and drains into the tank overflow assembly. Please note that I have manually pulled the leveling device or rubber ball slightly upward to see if that would stop the flow, but that hasn't worked.
This tells me that your ball cock's leaking past the seat. What do you wish to do? Attempt to repair the ballcock or change it out? Cheers, Tom

Doug, that's interesting to learn a fill tube can siphon if it is too low. I thought that once the ballcock valve closes the entire fill supply is completely closed and you could not siphon through the valve.

In the fill valve, the water enters and hits the washer that stops it. After that it is split and goes in 2 directions. It goes down to the bottom and up through the refill tube. Basically this creates a syphon hose from the bottom of the tank to the over flow. To start a syphon all you have to do is get the water started in the overflow. To stop the syphon, simply do not let the fill hose go lower than the water level. That is why fluidmaster gives the white clip.
About 29 years ago I was working with an electrician on a construction job and he explained his problem to me. He had a new, very expensive color toilet that leaked. He had replaced every moving part on it and finally used epoxy to connect the tank to the bowl. Never had water show up but it always leaked. After he went into great detail of all that he had done, and that he had spent 200 dollars working on it, I told him I could fix it in 2 minutes. He did not believe me. I went to his house, saw the refill tube stuck way down in the overflow. I turned the stop on and flushed the toilet. When it was filled you could hear a trickle. I took my flashlight and looked down inside the overflow and saw it trickling. I showed him. He saw it trickle. I pulled the hose up on the sleeve to above the water level. It stopped. Never trickled again.

Thanks, learn something new every day.

Thanks for everybody's help. You guys are great!

Doug you were right, I just cut off an inch of tube to make sure it was a hair above the water line and the dripping stopped.

Now I can sleep at night!

By the way, tom, I have seen what you described too. I was going on a hunch.

Thank you a million times. I just checked my overflow and the refill tube was too low. This stopped a leak that made a huge water bill. I replaced the flapper twice and was flipping out. Thank you so much!!

You have to look down in the overflfow with a flashlight because when I first looked at the refill tube, I thought it looked fine, but when I peeked in with the flashlight I saw the water and moved the tube up a bit and it stopped, no more leak. Yeah