Bathroom sink faucets 101
Pop-up drain stoppers in bathroom sinks are a convenient inventions, says the Littleton plumber expert, but fixing them requires you to crawl around under and behind the sink – tough duty if your bathroom sink is mounted in a vanity cabinet. Â You will have to unload everything you have stored under the sink (be careful to put any toxic items out of the reach of children or pets), and use a flashlight to take a good look at what you are working on.
How pop-up drains work
The mechanics of a pop-up drain stopper are really pretty simple; the handle of the lift rod sits on top of the sink between the faucets and (usually) behind the spout, Â When the handle is raised, the pop-up drain closes; when the handle is pushed down, the drain opens.
Underneath the sink, the lift rod attaches to a perforated metal bar called the clevis by means of a clevis screw, which is loosened or tightened by hand or by screwdriver.
Also attached to the clevis with a spring clip is a pivot rod, which passes through a retaining nut into the drain. Â Beyond the retaining nut, the rod also passes through a pivot ball, a plastic gasket, and a washer. Â It then passes through a small loop in the tail end of the pop-up stopper. Â So – the lift rod connects to the clevis, which connects to the pivot rod, which connects to the pip=up stopper. Â Got it?
Adjusting the pop-up stopper mechanism
If the pop-up stopper doesn’t sit tight in the drain when you raise the lift rod:
*Loosen the clevis screw (with your fingers, a screwdriver, or an adjustable wrench, depending on the type of screw);
*Push the stopper down by hand to close the drain;
*Tighten the clevis screw.  Once  you make this adjustment, the stopper should close snugly.
If the pop-up stopper doesn’t stay open when you push down the lift rod:
*Squeeze the spring clip and release the pivot rod from the clevis;
*Move the pivot rod to the next hole up on the clevis, holding it in place with the spring clip.
If you need to remove the pop-up stopper to clean out the drain, or for any other reason (you will need an adjustable wrench or slip jointed pliers with taped jaws to perform this repair):
*Loosen the retaining nut with the wrench and pull back the pivot rod, which will disengage the rod from the stopper. Â If you remove any parts fro the pivot rod, be sure to replace them in the right order;
Bathroom Faucet Preventive Maintenance: Â Bathroom drains get gunky with all of the hair and grooming products that slide down into the pipes. Â To prevent clogs, and prevent the need to go through the acrobatics of working under the sink to remove the pop-up stopper, do the following preventive maintenance:
1. Â Keep the stopper closed when you are using grooming aids, and wipe out the basin before you let the water run;
2. Â Once a month, run very hot (or a pot of boiling) water down each of your bathroom drains; this will help keep them flowing.
REMEMBER THIS: Â Pop-up bathroom sink stoppers are controlled from behind and underneath the sink. Â You will need a flashlight and some physical agility to squeeze in for the repair!
*Once the rod is disengaged from the stopper, you can lift it right out.
