Installing Pfister Push & Seal drain - still leaking

[Kestralyn]

I’m replacing the faucet, drain, water lines, and p-trap on the pedestal sink in my downstairs half-bath. I’ve been successful with the faucet, water lines, and p-trap, but the drain is fighting me and I could use some advice.

The drain is a Pfister Push & Seal that came with the faucet I installed. I’ve followed the instructions to the letter - at least five times, in fact. I can’t seem to form a seal between the drain and the sink. I get everything tightened up and when I test it, I get the same result every time: substantial leak from the drain hole. I’m not sure if it’s because my “hand tight” isn’t as tight as it needs to be, or if the sink (older, unknown maker) has too large a drain hole, or... ?

Do you have any suggestions, advice, etc. for this problem? I appreciate any assistance you can offer!

(Sorry for the long explanation. I don’t know the terminology well enough to make this any shorter.)

 

[breplum]

I don't know the push/seal product, but we only buy metal pop up assemblies, usually designated mpu from Delta. (at least in my day, being mostly retired, I haven't purchased product for a while).
The main trick with them is just at the exact spot on the underside where the rubber washer will be, we dab a bit of silicone on the threads because water will always spiral down those fine threads without a silicone dam preventing it.

 

[Kestralyn]

Thank you so much for the brain bump! I was thinking about silicone on the threads, but for some reason got stymied because the threads are below the sink, rather than inside the hole. I just popped the drain back out, siliconed under the gasket and around the body of the drain below. Cranked the whole thing down and let it cure. No leaks! Thanks so much!

I don't know the push/seal product, but we only buy metal pop up assemblies, usually designated mpu from Delta. (at least in my day, being mostly retired, I haven't purchased product for a while).
The main trick with them is just at the exact spot on the underside where the rubber washer will be, we dab a bit of silicone on the threads because water will always spiral down those fine threads without a silicone dam preventing it.