Our House came with a low profile Briggs toilet in the master bathroom. It is obviously a stylish and expensive unit but it has had some problems.
Briggs Toilet
The ballcock (fill valve) recently began
to leak again. I repaired it a few years earlier but I had to shop around
to find parts for the unusual ballcock assembly. Briggs advertises that it
is serviceable from the top but that makes it incompatible with readily
available fill valve replacements. This time I wanted to install a whole
new fill valve. I checked the prices of new ballcocks at BriggsPlumbing.com and was
shocked to see prices in the range of $150. Briggs Fill Valve
The original valve is made of brass. It
inserts from the top into a compartment inside the toilet tank. Typical
fill valves are installed through a hole in the bottom of the tank. I
purchased a replacement valve and a 1-1/4 inch diameter hole saw bit from
the local home center for less than $10 each. The hole saw has tungsten
carbide particles bonded to the pilot drill point and the cutting edge of
the saw and is intended for drilling ceramic tile and similar hard
materials. It was somewhat larger than the one inch diameter fill valve
but the rubber washer that comes with the fill valve might be large enough
to seal it. I decided to drill a hole through the bottom of the tank on
the right side where the fill valve would not interfere with the flush
valve. I left a little water in the tank to cool the bit and proceeded to
drill with my cordless drill. It was more difficult and time consuming
than I expected and I exchanged the cordless drill for a plug-in one
despite the potential shock hazard when working around water. After
several minutes the pilot drill broke through and after about ten minutes
of screeching noise the hole saw broke through. Unfortunately "broke
through" is too descriptive of what happened as I was bearing down pretty
hard on the drill and it caused some chipping on the underside of the
tank. Toilet Tank Showing Old Fill Valve
Compartment at Left; Cordless Drill With Hole Saw
Toilet Tank Showing New Hole for
Fill Valve; New Fill Valve
Preparing to Install New Fill
Valve; Inserting New Fill Valve in New Hole
New Fill Valve Installed
; Underside of Tank With New Supply Line Connected to Fill
Valve.
I was disappointed to find that the new
fill valve did not seal perfectly due to the oversize hole and chipping.
The leakage was fixed with liberal application of silicone caulk. The old
12-inch long supply line from the valve on the wall was too short to reach
the new valve location. The home center did not have a longer replacement
hose but they were able to connect two shorter hoses together. 
I
am pleased with the result of the modification since it will be easy and
inexpensive to replace the fill valve in the future. I would not hesitate
to undertake a similar task. However I would recommend that a smaller hole
saw or diamond core drill be used to provide a better fit. Also, less
pressure on the drill toward the end of the cut and drilling from under
the tank, if possible, would alleviate chipping.
Thanks Margie for
putting up with an out-of-service toilet for so long and for your help in
the repair.
Thormon Ellison