My Approach to Leaking Toilet Bowls
Bill Atkins posted a good article on toilet bowl leaking (http://lazydazearticles.blogspot.com/2009/08/toilet-bowl-seal-replacement.html), but included dealing with problems with the flush mechanism and the base. This article takes on a simpler task - water leaking out of the bowl, but not onto the floor, meaning you need to replace the upper seals. Parts of this article are purely my own thing, and I have not found anything published to support my approach. They work for me, and I am sharing my process with you. I am not saying that I recommend that you do the same. I will flag those parts in bold, so you can decide if you want to try what I do. It is written with the assumption that you have never, or rarely, dealt with this. Maybe you are like me my first time, dreading and fearful of the task. I have provided as much detail as I could, to help you through a task that really is pretty simple.
Few people I have talked with do what I do. Most have repeat leakage without knowing why. It is like a good paint job - it is mostly in the surface prep.
If water does not remain in your toilet bowl, you have a leak - somewhere. It can be in three and only three places. Let’s start by giving names to the parts for discussion. These may not be “by the book” names but they work for me.
The bowl - This is the toilet itself, the porcelain part with a hole in the bottom and a rim around the top.
The flush pedal - This is the pedal to the left of the bowl as you face it.
The flush nozzle - This is the connection to the back of the bowl that feeds water into the bowl’s rim to rinse the bowl.
The flush spray - This is the hand held spray used to help rinse the bowl.
The flush dome - This is the curved plastic part that closes the hole at the bottom of the bowl, and opens when you press the flush pedal down.
The upper seals - These are the two neoprene gaskets whose edges can be seen between the bowl and the flush dome. There are two - a thick upper seal and a thin lower seal.
The pedestal cover - This is the plastic part that splits near the axle of the flush pedal and covers the black pedestal base, the split ring and the band clamp.
The split ring or half clamp - This is a two piece ring with a V-shaped inner surface that pulls the bowl and the pedestal base together.
The band clamp - This is a clamp that, when tightened, pulls the two pieces of the split ring together, locking the bowl to the pedestal base.
The plastic pedestal base - This is the black plastic base on which the bowl sits.
I think that covers the parts. Let’s talk about the possibilities for leaking. For water to get out of the bowl, there are only three possibilities. The water can seep between the bowl and the thick upper seal, eventually getting to the interior flanges that stiffen the plastic pedestal base. This water can be the source of odors, as there is a slight ability for air to escape past the outer edge of the plastic pedestal base. Water can also seep between the thick upper seal and the thin lower seal, though unlikely, again getting to the flange area in the plastic pedestal base. Finally, water can seep past the thin lower seal and the flush dome, dripping into the black tank. Just like stalactites forming in a cave, moisture containing calcium from a hard water source and urine salts from us, sitting on the dome below the seals and evaporating, leaves behind minerals. As the deposits grow, the seal becomes worse and worse.
Why does a leak happen? If you just changed the seals and it leaks, either the mating surfaces were not clean, the seals were not aligned properly, or the half clamps were not tightened sufficiently. If the seals have been in place for a while and they slowly begin to leak, foreign matter is compromising the seals, either between the bowl and the thick upper seal, between the two seals, or between the thin lower seal and the flush dome. A little chemistry - once a crystal or mineral deposit begins to form, it attracts more material to it. Deposits will grow, even between well-seated surfaces. This is what causes the seals to fail. There is one more possibility - the flush dome might have shifted out of alignment, preventing a seal, but that is beyond this article. See Bill’s article for that condition.
The most likely scenario is foreign matter accumulation. That can happen in several ways. Liquid waste contains minerals and salts. Crystallization and accumulation over time can cause a leak. When it happens, it is time to change the seals. That is what the remainder of this article focuses on.
Before starting, you will need new seals, white vinegar, an aluminum pan large enough for the bowl to sit in it with vinegar in the pan, dry silicone lube spray, vaseline, a garbage bag, a socket set with a 5/16” socket and an extension, a straight blade screwdriver, an old toothbrush, a scrub brush, a spray cleaner such as Fantastic or 409, Pledge spray wax or similar, lots of paper towels, and if you can find one, a bulb syringe with a small tip. You will want rubber or latex gloves. My bowl seal kit is #385311462. Check your toilet model to be sure you have the right seals.
First, turn off the water, and flush until there is no more water in the bowl.
Close windows and doors, making the RV as air tight as possible. Open the bathroom vent slightly and switch the fan OFF. Open the other vent and switch the fan to high, with the fan set so it is pulling air IN, not out. This will create a positive pressure in the RV so odors from the open tank are pushed down into the tank, giving you an odor-free work environment.
Remove the toilet seat and seat back. There are screws by the seat hinges that hold them in place. With a flat blade screwdriver, pop the covers up to access the screw heads and reach behind the bowl to hold the screw bases. Unscrew the screws, and set the pieces aside.
The pedestal cover splits at the flush mechanism at the base of the flush pedal. You may find you need to remove the trim on the flush pedal to do this, but I can usually get the pedestal cover off with a little fussing and wiggling. Pressing the lower edge of the cover at the seam behind the flush mechanism, front side right at the bottom with the screwdriver usually does it for me. Remove the pedestal cover and set it aside for cleaning if there is any sign of staining or dried urine. If you have ever had male kids visit, I can almost guarantee there will be some.
Feel the band clamp at the back of the bowl. There is a nut there. With the socket on the extension and ratchet, loosen the nut until the band clamp can be slid down off the half clamp or split ring. Remove both parts of the half clamp. As with the pedestal cover, look for staining or deposits and if present, clean before re-assembly.
The bowl is now loose, so be careful not to push it off the base or drop it.
Reach behind the bowl and feel the flush nozzle where it attaches to the bowl. This is a rubber or soft plastic friction connection. You need to remove the nozzle. it pulls straight out, but is not easy. I do it by tilting the bowl toward me to get more room, and by twisting the nozzle in a rotating fashion as I am pulling it out of the hole in which it is seated.
Put the aluminum pan in the shower. Lift the bowl off the base and put it in the pan. Be careful to have a good hold so you do not drop the bowl. Using a funnel, tip the bowl toward the front and pour a substantial amount of vinegar into the hole at the back where the nozzle connected. Your objective here is to first douse the ring area, which distributes rinse water around the bowl, with vinegar, then to have enough vinegar in the bottom of the pan so any crystallized salts on the bottom of the bowl have time to soften for removal. If you just pour vinegar into the pan, it will deal with the base of the bowl, but any mold in the ring will not be touched.
OK, back to the toilet base. You are now looking at the two seals sitting above the flush dome. There is a notch in the edge of the seals. Note how the notch is positioned to fit on the plastic pedestal base, so the replacement seals will go in the right way. Remove the two seals and drop them in the trash bag. You are now looking at the flush dome. Odds are, the surface will have an accumulation of salts. Dribble some vinegar on the flush dome. Roll up some paper towels, drench them in vinegar, and form a ring on the flush dome with them to hold vinegar in contact with the salts. Let it sit to soften any deposits. Occasionally, dribble some more vinegar on the dome.
While the vinegar is doing its job, let’s deal with the flange area in the plastic pedestal base. Odds are, it will have liquid partially or fully filling the spaces between the flanges. Remove the liquid. I use a bulb syringe, but it can be blotted up with paper towels and patience, by rolling the paper towels into a shaft and sticking the end into the flange so the liquid is soaked up.
Clean any stuff that you set aside for cleaning. You CAN turn the water back on and use the shower to do this. Just be careful not to press down the flush pedal if you do so. Get those parts squeaky clean and dry.
OK, turn the bowl upside down. Look at the base around the hole where the bowl will rest on the seals. Most likely, you will see a ring of yellowish deposits. Scraping with the side of the screwdriver will usually clean those deposits. Once the deposits are removed, feel the surface. If you feel ANY roughness, you need to get this smooth. My first time doing this was after three years of fulltiming, and there was a lot of accumulation of very hard material there. I needed to use a file, then sandpaper, to get rid of the salt encrustation. (This is the first of the things that I do. If you try it, be very careful not to damage the porcelain, and just remove the salts. It took some patience that first time, but has been simple since then.) You want to get rid of every salt or mineral present, as any remaining will attract more salts, speeding the regrowing of the crystals. After that first, very hard deposit, my future seal changes, done annually, do not need real aggressive cleaning. I scrape with the side of the screwdriver, popping the hard stuff off, then I scrub any remainder. An old toothbrush (not Dorothy’s, Don) with vinegar usually does the trick. When all salts have been removed, I add more vinegar to the inside of the rim and scrub with a scrub brush to get the underside of the rim clean. I then rinse the bowl thoroughly with hot water from the shower, scrub all surfaces in the bowl with a scrub brush and spray cleaner, and rinse again. I fold up and discard the aluminum pan, leaving the bowl upside down on a number of paper towels to protect the shower base from scratching. I dry the base of the bowl where it will mate with the thick upper seal.
Now it is time to clean the flush dome. Hopefully, vinegar and the toothbrush will be enough. I have encountered quite hard deposits that I remove by VERY careful scraping with the side of a flat blade screwdriver, finishing with a very fine sandpaper until the flush dome is smooth and clean. (This is the second of the things I do that is not supported. If you slip and scratch the flush dome, you will have to replace it.) The best way is to soak with vinegar to soften deposits, then scrape with a material such as wood or plastic that will not damage the flush dome, then soak and scrape again, until all deposits are gone.
With the spray cleaner and paper towels, clean the flush dome thoroughly and rinse, then dry it. Now, give it several coats of Pledge spray wax. Your objective is to wind up with a thoroughly smooth, clean flush dome with a waxed surface that will seal well to the thin lower seal.
I then spray the underside of the thin lower seal with dry silicone lube (my own idea) and position it on the plastic pedestal base. The intent of the lube is to promote smooth sliding of the flush dome against the seal.
Next, I rub a very thin film of vaseline on the upper surface of the thin lower seal and the lower surface of the thick upper seal. I do NOT gob it on, but apply just enough to get a shiny surface. This promotes a very good seal between the two neoprene surfaces. (Again, this is my own idea, not supported. Vaseline, like all petroleum products, degrades neoprene rubber. None of the vaseline uses are necessary for re-assembly. My own opinion is that a thin film improves the seal and reduces water adhesion so rinsing is more thorough.) Mate the two seals, making sure they are aligned properly.
Now it is time to place the bowl on the upper seal. First, turn the water off and drain the line so if you bump the flush pedal, you won’t spray the room. (I do a thin film of vaseline on the top of the thick upper seal and on the dried bottom of the bowl where it contacts the seal. Again, this is my own thing, but the ONLY times I have found the flange area dry or nearly so on seal changing is when I have previously done this. Also, cleaning the bottom of the bowl got much easier after I began using a thin film of vaseline there.) Place the bowl on the seals in the approximate position. Re-insert the nozzle in the back of the bowl, seating it fully. Now position the bowl carefully. You have it right when, if you stand over the bowl and look straight down, you see a uniform black ring from the seals in the hole.
Position the split ring half clamps in place, with the front, with the two tabs, together and the rear having a gap. Place the band clamp over the split ring to hold it in place. This may take a bit of jiggling and juggling to get the split ring and the band clamp in place. Take the time to get it right. The two parts of the split ring should be straddling the bottom of the bowl and the top of the plastic pedestal base, with the split ring joined in the front, apart at the back, and the band clamp sitting evenly in the groove on the split ring all the way around. (Before I do this, I spray the bowl base and the inside of the split ring pieces with dry silicone lube. As you tighten the band clamp, the split ring will pull the pedestal base and the bowl together. The surfaces need to slide on the split ring for this to happen. I find the dry lube to help this process, but support for this cannot be found anywhere.) Make sure the band clamp nut is at the back of the bowl, else the pedestal cover will not fit in place. Tighten the band clamp until the split rings are in place and the band clamp is snug but not yet tight. Check the alignment of the bowl again and if necessary tweak its position until it is just right.
Now it is time to tighten the band clamp. You need to do this carefully. Go too tight, and you can crack the bowl. Too loose, and the bowl will shift and move with use, causing leaks. Here is how I do it. First, I get rid of the ratchet and use a nut driver (like a screwdriver but with an end that allows the attachment of a socket). If you do not have a nut driver and are using the ratchet, be gentle with that ratchet handle. Don’t pull too hard. Snug up the clamp until the resistance to tightening is building noticeably. Re-assemble the toilet seat and seat back. Check the bowl alignment. Now, sit on the bowl and wiggle. This will compress the seals and gain some slack in the band clamp. Again, tighten until resistance builds. Sit. Wiggle. Tighten. Repeat until you are no longer creating slack by wiggling.
Finally, replace the pedestal cover. Hold it so the bulge is at the top and facing away from you. Slide it in place beginning on the right, maneuvering it around the back, over the nut, then rotating the edge forward until it seats behind the flush mechanism. Now rotate the other side around to meet the seam and snap the two edges in place. It may take a bit of wiggling of the cover to get the two edges to snap together.
You are done.
You may notice, however, after a few weeks of use, that the bowl wiggles a bit. This sometimes happens as the seals continue to compress and the split ring adjusts itself over the bowl and base. It that occurs, simply tighten the band clamp a bit more.
So, how much time does this take? Well, I am used to it. Aside from time soaking in vinegar and cleaning, it takes me about 15 to 20 minutes to dis-assemble and re-assemble. Changing the seals regularly means I don’t need a lot of time soaking and cleaning, but my last change took about 2 hours, mostly sitting and waiting for vinegar to do its job.
Let’s close with maintenance. Periodically, get all the water out of the bowl that you can, add about a half inch of white vinegar, and let it sit for a while. Then, press the flush pedal to open the flush dome and scrub the edges with a stiff brush, removing all the sediment you can. Do another vinegar soak and scrub, then a thorough rinse with the flush spray. I do that once a month.
Ken Fears - October, 2016