sealing a flexible metal water supply to toilet

The water supply lines to the toilets in my house are chrome plated flexible metal. These are not the smooth metal lines, they are more like the flexible lines used to hook up gas connections. They are ribbed and sort of look spiraly wound or almost 'threaded'. They are not the braided stainless type.

Anyway, how do I seal these to the toilet? I have tried several different cone washers and can't seem to get a seal.

I should replace these lines, but I can't remove them without removing the valve at the wall and I'm not ready to shut off the water supply to the house and drain these lines so I just want to seal the connection with the existing flexible lines for the present time.

thanks

I am not exaggerating when I say those lines are a flood waiting to happen. They become brittle and corroded with age, and the least movement can cause a crack in a corrugation, or cause it to snap off at the valve. NO plumber I know would touch one. We insist that they be replaced as part of the job.

Now, as to your specific question, the cone washer you need to use with those is a special one, which is actually threaded on the inside, to mate with the twists of the corrugations. This provides both a seal, and a mechanical "grab" so the line does not pull back. A smooth washer cannot seal into the deep corrugations, and does not grab the pipe firmly, so blowout is a real possibility.

I do urge you to replace any and all of those as soon as possible.

I Agree with jimbo, I would get a braded stainless supply line, replace the stop, and be done with it.

Was it Franklin who sad a Oz. of prevention is worth a Lb. of cure.

Thanks jimbo, thanks Cass. I did a quick survey and I only have the flexible metal supply lines to the toilets; the sinks all use regular copper pipe from the cutoff valve to the faucets. I'm not sure why the builder decided to save a few cents per connection back in '92 when the house was built, but I think I'll go ahead and replace the flexible metal lines as per you recommendation.

thanks for the input.