down stem of sink over flowing

[djmorando]

In a bathroom sink I cannot figure out why this continues to overflow. I've replaced those traps and plastic pipes plenty of other times and had no issues.
The top of the trap that connects to the down stem of the sink continues to over flow. I've checked for clogs and find none. i've replaced the trap and other parts. I've put thread tape around all threads. When the water is on full blast it continues to leak under the sink, over the top of the trap that connects to the sink's down stem. my last idea is to put plumbers putty in that spot to block the water from coming out, but when the job is done correctly i know that shouldn't NEED to be an option in the first place. Any ideas or solutions would be greatly appreciated. thanks for reading and any and all help you can provide.

Gratefully yours,
David

 

[Mr_David]

Post a picture. could be something obvious

 

[djmorando]

I'll go snap some pics for you. Not sure it'll show anything helpful but I'll try to have some good pics in the next 20 min or so

 

[djmorando]

So it's leaking at the top of that trap where the black down stem meets the white trap. when the water is turned on all the way that's where it decides to spill out.

 

[Mr_David]

Thnks for the photo.

There should be a tapered nylon washer.
the pop-up drain assembly is 1-1/4"
the p-trap is 1-1/2"

You need the thicker washer. It should fit snug onto the black tail pc.

The tapered end down.

Also the black tail pc may not be long enough

 

[djmorando]

Mr_David,
Thank you for taking the time to guide me with this. I'll give it a whirl as soon as I can make a pit stop to pick up that thicker gasket. I'll be sure to post the results (fingers crossed). This simple issue has been the cause of much frustration and several headaches from the time spent troubleshooting and working to fix this myself. I just couldn't fathom paying someone hundreds of my hard earned money to repair this for my parents. I knew this had to be some sort of simple fix as it wasn't a complicated problem, however my plumbing experience is very little but I'm also not a complete dumb ass... so I've got that going for me lo Thanks again amigo,

Gratefully yours,
David M.

 

[Matt30]

If that washer doesn't work, it's possible the tail piece (what you are calling a sink stem) may be a tad short. From the photo it looks very close to coming up short. The washer that's there might not have enough to bite onto.

 

[havasu]

This new house had the exact problem. The tailpiece was just too short to stop a leak. I bought a longer one, cut it to just bottom out at the taper, and now works fine. Total cost ~$4.00.