Bathroom sink leak

[sheahasu]

I could have sworn I posted this already, but can't find it, so I'm posting again.

I just replaced my bathroom faucet and drain. No problem with the faucet. However, I cannot figure out how to stop a leak in the tail pipe assembly.

I started with plumber's putty for the drain seat, but switched to silicone when I realized the putty wouldn't work with the plastic seat. Silicone seems to work as I'm not getting any leaking when I have the sink filled and closed. But when I run the water, it starts leaking around the gasket. I have teflon tape on the threads at the top where it screws into the seat, so that's good and tight.

I have tried a different pipe (metal instead of plastic) a different gasket,pushing up the gasket first, then tightening the...not sure what to call it since it's not really a nut...whatever. Without being able to observe top and bottom simultaneously, I can't tell for sure where the leak originates. From underneath it seems like it must be actually getting water between the pipe and the sink itself, then squeezing around the gasket. The only way it could do that, though, at least as far as I can see, is for the water in the pipe to be backing up and draining through the overflow holes. The pipe is the same length as the one on previously, but I've been wondering if maybe the tail pipe is going too far down into the trap, then backing up. Don't know why it would be since it's the same length, but I'm out of ideas.

Any help would be appreciated. I've been without a sink for over a week. I have another faucet to replace as well, but I don't want to risk being without ANY sink, so it's staying in the box until I get this figured out.

[lefty]

What's leaking is called a 'pop-up valve'. The flange on top appears to be sealed to the basin, since it doesn't leak out water when you close the stopper and put water in the sink. From underneath, where the bottom of the valve comes through the basin, you should be installing a rubber cone washer, with the cone side up, a flat washer, and then the nut. No tape or pipe dope is needed. Tighten the nut until the leak stops. Before you install all of that, check the hole in the bottom of the basin and make sure that it isn't cracked or deformed, and dosn't have some other sort of problem. The edge of the hole needs to be fairly smooth.

[sheahasu]

I have the rubber washer in place. The pipe assembly itself is plastic, and there is no washer--it's just a really wide nut and the rubber gasket. I did try using the old metal pipe, which has all three--the gasket, the washer, and the nut. Still had the problem. the directions say to hand tighten, although a guy at Menard's said to tighten it with a wrench. Did both. Still leaks.

[lefty]

That big rubber washer is what forms the seal between the bottom of the bosl and the pipe of the pop-up valve. If tightening with a wrench or pair of pliers won't make it stop leaking, either replace the washer, or,you might try putting a little silicone on it and reinstalling it.

[sheahasu]

That was my next thought. I just went and redid it again, with silicone along the gasket this time. I'll see what happens in 24 hours!

[sheahasu]

Lefty, the silicone on the gasket seemed to do the trick. Yee haw! Now I can finally install the second faucet and hopefully not have to take a week to stop a leak! Thanks for your help.

[lefty]

Not the preferred fix, but if it works, we'll take it!!

[sheahasu]

Well, as I uninstalled the second one, I saw that the entire top of the pipe had been wrapped in plumber's putty to make it fit tightly into the bowl. No wonder it never leaked! The first one the putty had pretty much disintegrated, so I didn't realize there was more than just around the seat. Had I seen that, I would have tried silicone to begin with! Oh, well. It's fixed now and looks great. I can be happy and both my husband and I can wash our hands!

[dcartistic]

How much silicone did you put on the gasket? I'm having the same problem. The manufacturer -- Peerless Faucet -- sent me a metal tailpiece (the original was plastic and I was having a leak problem with the gasket with that piece, so that's why they sent me a metal replacement), but it STILL leaked around the gasket, even though I had tightened it and sealed it with putty. I'm going back to the plastic because it's easier to tighten...

Thanks,
Craig

[sheahasu]

I'm happy to say it worked on my second pipe, too. My faucet manufacturer didn't mention using putty or silicone at all, not even for the seat! From looking at my old pipe, it looked like there had been a ton of it so that it would essentially seal completely between the pipe and the basin. Since putty won't work with plastic, I used the silicone. I just put a line all the way around the edge where it comes in contact with the basin itself, then tightened everything up. Basically it sealed the gasket to the basin bottom. Of course, silicone came squeezing out, but I just left it since no one will see it. And I'm also paranoid that I'd wipe away too much and still have a leak! I hope it works for you. Nothing more annoying than trying to follow instructions and not have them work. It would have been nice to have those steps as part of the directions to begin with and save myself the headache of the last week! Good luck. Post back to tell me how it goes.

[dcartistic]

Yep, that did it! Thanks for the tip!