We have an American Standard lifetime whirlpool tub with the pop up drain (white). However, the pop up drain plug has always been tempermental but now it no longer wants to stay down.

Should only take about 6-8 min to fill and about 4 min to drain.

Put the lever in the open position so that you can grab the stopper. After you get a grip on it, put the lever in the closed position and the drain plug and rocker assembly will pull out in a horizontal direction.

buy another one and use it as a model to put yours back together then take it back for a refund.

some people use spray foam which you can add later

yes, it could be.also may be build up of waste,(hair,etc) is the rest of bath room performing ok,has this problem just appeared ?just something's to look into

Adjust the screw head at the bottom of the stopper.

You have to take apart the "drain rod" assembly under the sink. There will be a rod with nut on it that goes into the drain near the sink. Take the nut off, drop the stopper in with the eye hole towards the wall and then reinstall the rod through the eye on the stopper and tighten the nut.

It could be the pressure on the drain isn't allowing the rubber around the drain pop up to come unlodged from the floor of the tub. I have ran into this problem a few times. the best way we found to take care of it was to install a push pull type drain assembly or try and adjust the drain pop up so it pops up higher allowing the rubber around it to break the seal and start to drain. take some pictures and post them i might be able to help more

Remove the lift rod and lift up the stopper.
The lift rod is under the sink and one end goes to the lift rod and the other end goes into he base of the plug.