Changing a bathroom lavatory sink is fundamentally a simple job, but it can be very frustrating if you do not have the proper tools and materials handy before you start, so with that in mind i will first give you a checklist of tools and materials.
1. 10" Channel lock pliers (to disconnect drain fittings)
2. 6" or 8" ajustable wrench (for the compression nuts on the water supply lines)
3. You may need a medium sized flat screwdriver or a 1/4" or 5/16" socket or nut driver to remove and reset the bowl hangers.
4. A small container of Plumbers putty or a small tube of Clear silicone sealer. (Check your new bowl installation specs carefully. Some cultered marble or natural stone products recommend you do not use plumbers putty because the oils may stain the finished product.)
5. I would recommend installing new water supply lines.
a. If this is a pedastal sink where the lines will be exposed you should use the chrome plated brass lines for appearance. If so, you will need a tubing cutter to adjust the length of the lines.
b. If you are installing the sink on a cabinet base you could use the metal lines, formed PVC supply lines or the ready made braided lines.
You will find it is much easier to install the faucett before you set the sink in place, therefore if you are planning to take the faucett off the old sink and re-use it, it would be best to pull the old sink first.
1.Turn the angle stop valves off, then open the faucett to prove that they shutoff and hold. If they leak it would be best to turn the water off at your water main.
2.With the water off, hold a small plastic container under the angle stop valve to catch any water that leaks when you disconnect the lines (an old margarine tub works great here)
3.Use the Channel lock pliers to hold the valve steady while you disconnect the packing nut at the base of the water supply tube. When the nut is loose back it off with your fingers and pull the line out of the angle stop valve.
4.Repeat step 3 on the other water line.
5. Place a container under the P-trap and disconnect the compresson nut on the top of the P-trap. You should expect about a cup of water in the trap. (If your present sink has the chrome plated brass tailpiece and P-tap there is a strong likelihood that it will crumble in your hands as you try to remove it. This is a common problem of metal pipes. The easy solution would be to plan on replacing the P-trap with a PVC trap.
6. Once you have the water and drain lines disconnected look on the underside of the sink and locate the hangers. (Normally metal sinks will have hangars but synthetic materials will normally just be glued to the countertop with silicone.) If you have hangers, remove them, if not, you will need a stiff putty knife inserted under the outer rim of the bowl on the top of the counter surface to carefully break the silicone seal. (I recommend a painters 5in1 tool for this step.) Once the bowl is loose you will be able to lift it up and set is aside.
7. Carefully clean the old silicone sealer from the countertop where the sink sets. (here again the painters 5in1 tool works great).
8. If you are planning to re-use the faucett you can easily remove it from the old sink at this time. First Disconnect the drain pop up handle linkage on the underside of the sink, then unscrew the nut on the top of the water lines and remove the water lines. You can then unscrew the faucett mounting nuts and lift the faucett off the sink.
In most cases you will find the tailpiece is corroded in and it is a real hassle to remove. I generally just plan on replacing that part.
At this point you will be ready to start installing the new sink.
Basically to install the new sink you will reverse the procedure that we used to remove the old one.
1. carefully unpack your new sink and examine it carefully for any cracks, chips or defects.
2.Locate the manufacturers installation instructions and read them carefully.
3. check the faucett carefully. Many of them have a plastic template that will fit under the faucett. If so, apply a light film of clear silicone on the edges of the template on both the upper surface where it will fit against the faucett and on the underside.
4. Pass the water line tubes through the sink and install the faucett lock nuts on the underside. Tighten the nut snugly to lock the faucett in place.
5. Attach the upper end of the water lines to the faucett.
6. Before installing the drain assembly you will need to apply plumbers putty or silicone to the underside of the drain flange where it will meet the upper side of the sink.
Some tailpieces drop down from the top and a large rubber gasket/bushing is slipped over the tailpiece and up against the underside of the sink, then a locknut is screwed up tight against the rubber bushing to hold the tailpiece tightly in place.
There is another type which has a top flange that unscrews off the pipe. Remove the flange, then slide the locknut down from the top to the threads on the lower part of the tube. Screw the nut down to the lowest part of the threads. You then drop the rubber bushing down the tube until it rests on the nut you just applied. You then slip the tube up through the sink from the bottom and screw the Trim flange on the top. You can now tighten the nut upwards which will pull the tube and flange down firmly against the sink bowl.
Now drop the drain control rod down through the faucett from the top and connect it to the linkage extending out of the drain tailpiece.
Apply a light bead of silicone on the underside of the sink rim,then carefully drop the sink into the cabinet opening and if your sink has mounting clips install them. Next wipe any excess silicone off the edge of the sink or countertop.
Connect the P-trap to the tailpiece from the sink and the discharge end to the Trap adapter on the waste arm pipe extending out of the wall.(You may need to cut the tailpiece or P-trap end to fit.)
Attach the water lines to the angle stops)
If you used plumbers putty to attach the drain tailpiece flange to the sink you may now turn the water on and check for leaks.
If you used silicone to seal the flange to the sink you should wait 12 hours to allow the silicone to set before running water in the sink.