Vanity drain gasket replacement

[KiviP]

Quick question. I have a Kohler bath sink drain and just opened up the box before installation. The rubber gasket that goes under the drain hole, is a bit roughed up. It is a threaded gasket so whoever put it in the package showed no love to it. Kohler sells the gasket for 2 bucks and I ordered a new one just in case.
Now my question is that the gasket is pretty tight on it. Everytime i turn it, i see rubber shavings coming off of it.
Should I put dish soap or silicon grease on the new one to make it easier to screw on and tighten on the threads?

 

[WorthFlorida]

It should be relatively soft and it will conform to the sink. The sink drain hole is probably has a rougher surface than this gasket. The real seal is under the drain flange on top. Use silicone or stainless plumbers putty. This gasket allows it to wiggle a bit to conform to the hole and seals water only when water comes down from the sink overflow. There is no pressure other than gravity Unless it is installed too lose, I've never seen one leak. Usually when it does is the side drain holes are too low and are below the gasket because the top flange was not threaded in all the way into the tail piece.

With the flange removed be sure the tail piece nut is all the way down. From the bottom insert the tail piece into the drain, with silicone under the flange from the top threaded it onto the tail piece until it bottoms out. Then tighten up the nut.

 

[Sponsor]

 

[Tuttles Revenge]

The cone washer (theres some fancy term that I've only read on these forums) is the achilles heel of a bathroom sink drain. They are pushed up and seal agains the sink, but the threaded portion often is difficult to seal. If I have problems with the seal on the inside threaded portion, I just add some silicone sealant only on the threads where the washer makes contact, but not where the nut does or it seizes the nut. Some people use pipe dope on those threads for the same purpose and don't have to worry as much about the nut seizing.

 

[KiviP]

It should be relatively soft and it will conform to the sink. The sink drain hole is probably has a rougher surface than this gasket. The real seal is under the drain flange on top. Use silicone or stainless plumbers putty. This gasket allows it to wiggle a bit to conform to the hole and seals water only when water comes down from the sink overflow. There is no pressure other than gravity Unless it is installed too lose, I've never seen one leak. Usually when it does is the side drain holes are too low and are below the gasket because the top flange was not threaded in all the way into the tail piece.

With the flange removed be sure the tail piece nut is all the way down. From the bottom insert the tail piece into the drain, with silicone under the flange from the top threaded it onto the tail piece until it bottoms out. Then tighten up the nut.

View attachment 90886

Thanks, that I what I usually do for other sinks/drain I installed but the cone gasket sometimes does not seal the threads properly and it leaks from the threads itself.

 

[hj]

You coulol have saved $2.00 by calling 1-800-4KOHLER.

 

[KiviP]

The cone washer (theres some fancy term that I've only read on these forums) is the achilles heel of a bathroom sink drain. They are pushed up and seal agains the sink, but the threaded portion often is difficult to seal. If I have problems with the seal on the inside threaded portion, I just add some silicone sealant only on the threads where the washer makes contact, but not where the nut does or it seizes the nut. Some people use pipe dope on those threads for the same purpose and don't have to worry as much about the nut seizing.

Totally agreed. I have installed 3-4 pop up drains and never had a leak from the gasket itself around the basin. I have had 1-2 have a slow leak from the threads where the gasket is. The design is not that great and it is a gamble for the threads to seal properly. That is why I ordered a replacement cone gasket as it looked a bit rough and I think it will allow water through the threads.
Here is one I currently have that do not leak, but it shows that at some point enough gunk got in there to block it somehow.

As for the silicone, I never silicone the flange since that is really not for sealing the drain and it is annoying to remove it later. However I never tried silicon underneath the basin. I know some people use dope or putty but it seems like both are not really approved on rubber (at least not the generic stuff sold in HD or local stores). So I might just put silicone as a safety measure. Do you mean putting the silicone over the cone gasket where it is going to be tightened down? I wont for sure put it over or below the nut since that is going to be a nightmare to remove later. I had a plumber silicone my kitchen disposal drain and it leaked. Taking it out was a PITA

 

[KiviP]

You coulol have saved $2.00 by calling 1-800-4KOHLER.

I called and was told by the rep 'not sure what the part# is and just follow the manual'
To be honest 2 bucks is better than spending an hour on the phone for a gasket

 

[Tuttles Revenge]

I place the threaded flange down through the hole and mark the threads with black sharpie where the cone washer will set. Then Just as I slide the cone washer up, I coat the threads with silicone sealant and slide the washer up. Not too worried if any gets on the face of the washer, its easy enough to peel off if needed. Makes up for any potential quality issue in that weak point of the system.