Sink drain lets water out

[SkyDaver]

The bathroom sinks in my son's house have a push-type pop up drain. You push on the drain cap, and the sink should seal, you push again, and the cap comes up so the water will drain out.

His pop-up won't seal tightly, and the water slowly drains out. The rate is such that it drains out before he finishes shaving.

We got replacements from a distributor, but those aren't holding water, either. (The sink and drains are by Fresca)

Any ideas? If we have to, I suppose we can go with another brand.

This isn't the kind with the pivot rod that actuates the pop-up; it's spring loaded & all contained in the drain.

The sink isn't leaking, the drain cap is leaking into the drain.

It's sort of like this drain:
http://www.amazon.com/dp/B0059WKLVM/ref=dra_a_cs_mr_hn_it_P1400_1000?tag=dradis-20

 

[Blue Jay]

Is it possible to make any adjustments? I would think their should be something for the down catch.

 

[SkyDaver]

I think that it's latching in place about as far down as it will go.

 

[oldognewtrick]

Does the center of the drain plunger twist to adjust?

 

[SkyDaver]

Does the center of the drain plunger twist to adjust?

I'm not sure yet; I'm trying to help him from 300 miles away. He'll should be looking at it later today. We also have the same model replacement drains to examine. I'll try to get good pictures of it.