OT - Sink Drain

I recently installed the sink drain in the picture. The center tube (H) has holes through the wall of the treaded portion, which fits inside the drain opening of the sink. After installation, running the water with the stopper open resulted in a slow leak from the threaded interface between the outer wall of the center tube (H) and the lock nut (G) at the bottom. I conclude the water was escaping the inside of the center tube (H) through the aforementioned holes and then flowing down the outside of the tube (H) through the threaded interface between the rubber washer (F) and the lock nut (G). As a makeshift fix, I caulked the threaded interface at the bottom, which seemed to work.

It baffles me why the tube (H) has holes through its wall in the treaded portion? I think they are the root cause of the leak, and I have scratched my head bald trying to imagine what purpose the holes would serve?

Sorry for such an off-the-wall post, but I find a wealth of knowledge on this forum. So, I figured somebody can probably learn me something

Thanks,

Neil

Part "F" should be a conical rubber gasket that make the seal with the sink. There are two types of tubes, one with the holes in them and one with out (less thread length). If you have a sink with an overflow drain hole, the holes allow the over flow into the drain. If you have a sink with out the overflow hole, you may need the other shorter type without the holes.

Also check for hairline cracks around the sink drain hole (which could be caused by over tightening). These can weep as well. They should not be over tightened.

The holes match up with the internal drain passage of sinks that have an overflow port to direct water down the drain, rather than letting the sink overflow if left filling unattended.

If your sink does NOT have the internal overflow passage, you MAY have the wrong drain fitting for the sink.

Did you use "plumber's putty" when you installed the parts into the sink and the lower nut?

(quoted from post at 12:06:58 01/06/20) Part "F" should be a conical rubber gasket that make the seal with the sink. There are two types of tubes, one with the holes in them and one with out (less thread length). If you have a sink with an overflow drain hole, the holes allow the over flow into the drain. If you have a sink with out the overflow hole, you may need the other shorter type without the holes.

Also check for hairline cracks around the sink drain hole (which could be caused by over tightening). These can weep as well. They should not be over tightened.

Click to expand...

I knew I would learn something. I can't get to the sink right now, and I don't remember whether it has the overflow drain provision, but that does explain why the holes are there.

As you say, (F) is a conical rubber washer that seals to the base of the sink. Apparently, when I installed it, I did not get the washer to seal tightly to the outside of pipe (H), as the water ran between the outside of the pipe and the inside of the washer. I sort of thought maybe the washer is supposed to compress inwardly to seal against the outside of the pipe. But it apparently didn't, and I didn't want to overtighten.

In any event, thanks for info; it does solve the mystery of the holes.

Neil

(quoted from post at 12:13:41 01/06/20) The holes match up with the internal drain passage of sinks that have an overflow port to direct water down the drain, rather than letting the sink overflow if left filling unattended.

If your sink does NOT have the internal overflow passage, you MAY have the wrong drain fitting for the sink.

Did you use "plumber's putty" when you installed the parts into the sink and the lower nut?

Click to expand...

I did not use "plumber's putty." Initially, I applied silicone sealant only under the flange (E). That's the only place the instructions said to apply any goop (I am definitely a newbie when it comes to plumbing projects). As noted, I later applied caulking (also silicone) around the lower edge of the lock nut (G) where it meets the tube (H).

Now that I know more, I'll have to consider whether to rework the whole thing.

Thanks,

Neil

The proper way to install that is to put plumber's putty between part E and the sink body. The gasket - part F - should be contacting the sink body from underneath. Part E should be threaded down onto part H until it "bottoms." Then, part G should be tightened up to compress the gasket F and the plumber's putty under E.

You need to make sure that the part H is straight in relation to the sink. If it is tilted off to one side or the other, it will leak. It has to sit squarely onto the bottom of the sink.

I've put in a lot of them, and I haven't had one leak so far doing it as described.

Plumber's putty under E unless it has a rubber gasket with the kit. The last few I've installed didn't need putty. As stated below, thread E all the way on. Slide F and G up to the bowl. There's usually a metal or fiber washer between them. While you run the nut G up to snug, wiggle it to center the taper in hole. Don't overtighten G. They don't always sit straight down.

I just one like that and had the same problem.
Did everything according to instructions and used plumbers putty.
Still leaked.
Poor quality junk.
Richard

you have some good advice. Another small thing is that sometimes mineral deposits, soap, or parts of old gaskets will interfere with the seal of F against the bottom of the sink.

I did one too, following directions. Still leaked. Changed to a different brand, and that one held. Unfortunately, I can't remember what brand leaked, and which didn't, however, earlier I had used the "leaky" brand on a different sink and it worked fine. It's probably poor quality control at the factory.

Not for sure what the (F)I did on last one,
but best i remember, you need to tighten
the (H) outta (G).

(quoted from post at 16:31:19 01/06/20) Not for sure what the (F)I did on last one,
but best i remember, you need to tighten
the (H) outta (G).

Click to expand...

Lots of helpful responses here, and I find the comic relief of this one the most helpful

Thanks guys.

Neil

just a side note, if it's a new sink from man made material, plumbers putty will make it develope cracks around the bottom of the sink. ask me how i know...they recommend silicone..