Toto Drake supply leak

Installing a brand new Toto Drake. Everything went fine except for a very small leak where the braided supply line threads onto the filler.

The supply line is also brand new. I tried replacing it with another new one and still have the same problem. Inside the female compression fitting on the supply hose is a domed gasket with a hole in the middle for the water to pass through. To my eyes it's in good condition. Toto includes a spare domed gasket with the toilet -- I tried squeezing that spare inside the fitting too; it ended up getting pushed into the filler pipe. Still leaked.

I have even tried teflon tape, just out of sheer desperation. I think I'm tightening the connection enough -- I've taken it at least 1/2-past hand tight. Various instructions have said "only hand tight" or 1/4-past hand tight. None of these work.

One more thing -- the supply line is too long. I'm using a 12" line (only one easily available) when the distance is only about 8", so there's a pretty sizeable curve in the line between shutoff and filler. Could that be throwing off the geometry inside the connection? Do I need a shorter line?

If the supply lines are ok, the only other thing I can think of is that there's a problem with the filler pipe. Does Toto require using some kind of special line or connector?

Any help appreciated.

Curt

First, take your finger and feel the edge of the fill valve where the domed gasket inside the SS easy hooker mates up against. If there is a sharp edge (possibly a casting mark in the plastic) that you feel, take an emery board or file and grind it down to smooth the rough edge. Every now and then I come across this situation; no big deal to rectify. Replace that SS easy hooker with a 9" one, it will bend slightly at either end but will allow less of a hard turn into the fixed locations of the supply valve and fill valve. 12" work most of the time but you don't want real hard turns in them. This stresses the connections which over time can be problematic.

RUGGED is right, just check the bottom and maker sure it's smooth.
These American made fill valves are as standard as it gets.
And please, no Teflon tape on that connection.

Are you sure you didn't crossthread the connection?
The nut from the supply should thread on easily, not hard.
If it's going on hard, you're crossthreading it.
Slow down and straighten it up.

problem solved, and a new one

Problem was a hairline crack in the filler tube, starting from the base where the supply line gasket meets the filler and going up vertically. I was in denial that a piece of the new toilet could be defective, especially such an expensive toilet; but following the advice of the forum, my fingernail found the imperfection. Toto customer support overnighted a replacement with no trouble.

So the toilet is now in place and working great. Thanks for the advice. Now I have a new leak with which I need some help. I will post that info in a new thread.

Curt