Installing a Plunger-Valve Ballcock A ballcock is the only mechanical part on a toilet. It has a number of moving components that can wear out or break. Replacing the ballcock is relatively easy and takes about an hour to do.

Before you begin:
There are several types of ballcocks: plunger-valve, diaphragm, float-cup and floatless. They all use similar steps and methods for replacement, and you can replace a broken ballcock with the same type or use one of the other types.

Follow These Steps

Steps 1 - 6 of 6Print Project SheetEmail a Friend

  • Step One

    Shut off the water, and flush the toilet to empty the tank. From underneath the tank, place a bucket under the retaining nut, then remove the ballcock retaining nut with an adjustable wrench. Remove the old ballcock assembly.

  • Step Two

    Attach a new cone washer to the new ballcock tailpiece, and insert the tailpiece into the tank opening.

  • Step Three

    Align the float arm socket so that the float arm will pass behind the overflow pipe. Screw the float arm onto the ballcock. Screw the float ball onto the float arm.

  • Step Four

    Bend or clip the refill tube so that the tip is inside the overflow pipe.

  • Step Five

    Screw the mounting nut and the supply-type coupling nut onto the ballcock tailpiece, and tighten the nut with an adjustable wrench. Turn on the water and check for leaks. Don’t over-tighten the nut, as it can crack the toilet tank.

  • Step Six

    Adjust the water level in the tank so it is about a half inch below the top of the overflow pipe, or align with the "full" line inside the tank.

Skill Scale
Varies
Time Required
Experienced: 1 hour
Handy: 1.5 hours
Novice: 2 hours
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