How to leak test tub drain?

I just in stalled a typical tub drain: overflow, drain ell, and p-trap. Not sure how to verify it is leak tight. I can run water into it but that doesn't seem like it will be a very demanding test. I have a test balloon, not sure how to use it in this situation. Thanks.

Just this weekend I helped my son in law put a new tub in. After it was done, we filled the tub to the overflow line and let is set a few hours. That gave us confidence the drain shoe was sealed OK. We then ran water full blast to fill past the overflow. That let us see that the over flow was sealed. Finally, we opened the tub drain. That amount of water with a little head on it would have exposed any problems with the W/O, trap, etc.

The wall is completely exposed, so we have access visually, with flashlight and mirror. to the tub box area. And his young, flexible long arms actually could reach under and "hands on" all the fittings.

We are confident with this test.


It was a fun job, because in essence, the tub was about 60 1/8" long ( americast, with resin up around the flanges) and the rough where the old one piece came out was actually about 59 7/8". Needless to say, the sawzall got a workout on this job!

I did the test jimbo suggested and found that my drain shoe isn't sealed. Operator error - not enough silicone under the tub-side shoe fitting.

Question - can I use plumber's putty on an acrylic tub? The Kohler tub instructions say not to use products with petroleum distillates. I read the MSDS for Oatey plumber's putty, and there are some hydrocarbons. However, it didn't say petroleum distillate, specifically.

What is the recommended product to seal the pop up drain thingie - 100% silicone or plumber's putty? Thanks.

I use plumbers putty........ fill the tub with the drain closed. No leaks = good. Drain water no leaks = good ,,,,,,,,,,that simple