Fixing a leaking bowl:

Some weeks ago our toilet began leaking water from the bowl very slowly. I'd say it took about 24 hours for all the water (about a 1/2 gallon) to leak out.

Our toilet is model 3010 circa 2005 with a full china bowl. Sadly Dometic has obsoleted this model. This means not all parts are available anymore. They do offer the seal ring kit, replacement flush ball and a handful of other parts. These parts are usually enough to fix the leak and do general service.

Reference material to include a parts diagram and part numbers is HERE. Dyers RV Parts & Accessories can source what's available. Note that old part numbers need to be converted to their newer equivalents. Also the brass shaft that comes with the flush ball kit won't fit older toilets. You can use the old one over again.

Lacking a complete understanding of how the toilet is put together and mounted caused me a degree of pause with diving into the repair. The last thing I wanted to do was shut down the toilet for X number of days owing to something breaking and/or missing or incorrect replacement parts.

In my case (older toilet) the flush base is mounted to the floor with a flange ring. All of this can be left in place when removing the toilet. Below are the steps I used to remove the toilet and replace the worn out parts.

1) Remove beauty caps from china base mounting screws in 4 places.

2) Lift out control board and disconnect DC connector and flush motor connector. You'll need to lift out the circuit board to access the connections. These have two small retaining screws on either side of the connectors. Make sure connectors/wires are clear of the bowl and other parts. You DO NOT need to disconnect the connector to the flush switch.

3) There is a plastic water feed check valve that presses into a rubber grommet on the china bowl. Carefully pull this off.

4) At this point the china bowl can be lifted straight up and off the flush base mechanism. Put the bowl aside. Make sure that the seat doesn't swing and damage the circuit board if you place the china bowl on its back.

5) The parts I got included the rubber flush ball seal, gasket seal, flush ball and brass shaft. (Brass shaft didn't fit older control arm.)

6) An aluminum metal ring will unscrew from the top of the flush base. This allows the removal of the rubber flush ball seal and white plastic insert all of which are on top of the flush ball.

7) You'll need to disconnect the flush ball control arm by loosening its allen screw. There's a small retaining bracket with plastic spacer that needs to come out. Also the screw at the end of the control arm that engages the flush motor arm will need to be removed. I used some WD40 on the brass flush ball shaft. Once all of this is cleared, you can invert the flush ball and expose its mounting screw.

8) Remove the flush ball mounting screw. Remove the control arm from the shaft. This may require some tapping. The brass shaft needs to come out from inside the flush base (towards the flush ball). Once the shaft is out, the flush ball can be removed.

NOTE: I placed a wad of paper towels down inside the sewer line to avoid dropping something into the black water tank.

The new replacement shaft didn't match the original one. Thus it wouldn't fit into the control arm. I cleaned the old shaft up and put the new o-rings on which were supplied with the new shaft. I put grease on the o-rings and flush ball pivot.

While everything was apart, I cleaned the white plastic retainer ring (sits on top of the flush ball) and interior of the flush base and behind the flush ball where it opens. This area can't be accessed when the toilet is put together. An open flush ball blocks this portion of the interior of the flush base. Most of the build up is sludge and calcium. Note the white plastic retainer ring is keyed with tabs. Only goes in one way.

Make sure all the parts are clean before putting the new parts in. Especially any gasket mating surfaces or those sealing off water. I needed to use a scouring pad and a small piece of 150 sand paper to get things properly cleaned. I had a lot of sludge and calcium build up which in spots was tough to remove.

I opted to replace my flush ball just to be on the safe side owing to calcium deposits and wear. This may not be required to fix a leaking bowl.

On the china bowl there is a dark grey plastic seal ring. This is sealed to the china bowl with plumber's putty. This ring is slightly cupped toward the toilet and flat on the mating side with the flush base. Remove this ring and clean it thoroughly. Make sure the china bowl mating surface is clean.


Pack in some plumber's putty in the cupped side of the seal ring that faces the china bowl. Press the seal ring into place to get a good connection with the plumber's putty and china bowl. This leaves a clean flat plastic surface facing the flush base.

Now that everything is clean and the seal ring is on the china bowl you can begin to put things back together.

1) With the flush ball and shaft in place, attach the control arm and tighten its allen screw. Be careful with the two limit switches whose rollers follow a flat spot on the control arm where it attaches to the flush ball shaft. You don't want to break these switches. Make sure the control arm goes back on the way it came off. Once it's in the proper position, tighten the allen screw. Put the retainer bracket with bushing back on. You can manually operate the flush ball now. You should hear the limit switches click when the ball is fully open or closed at extreme ends of its travel.

2) Install the white plastic retainer ring. It's keyed with tabs and will only go in one way.

3) Install the flush ball gasket (thin soft round rubber ring). Make sure to observe "This Side Up" makings.

4) Screw on the aluminum ring which presses the rubber gasket against the mating surfaces. Tighten this securely with your two thumbs. Close the flush ball and add some water on top with a cup to make sure no leaks exist. Water should stay put if everything is tight. Also make sure the flush ball is sliding under the gasket properly.

5) Open the flush ball and drain the water out.

6) Lay in the thick black foam seal gasket making sure to observe "This side up" marking. I used a small amount of high vacuum grease on top where the writing is.

7) Align the flush ball control arm with the flush motor control arm and install the screw pivot with bushing. If the plastic bushing is worn move the worn part away from contact points. Put a dab of glue or loctite on the exposed threads. This will prevent the screw from backing out. Operate the mechanism by hand to ensure it's working as expected.

8) Make sure you can access the 12VDC and flush base wiring when the china bowl is installed. Their connectors need to go back into the control board.

9) Put the china bowl back over the flush base and install the water feed line into its grommet.

10) Reconnect the flush motor connector then the 12VDC connector. Tighten all the retaining screws on the connectors (X4).

11) Put the control board back using its clips.

12) Replace china cover and four base mounting screws to include beauty caps.

Note: My base screws were stripped in the floor wood. I used a set of four plastic fasteners to create a good grab for the base screws. I also added rubber washers under the metal ones to avoid any potential cracking of the china base.

Please feel free to contribute and questions, comments, corrections and/or suggestions.

Evolve and simplify!
Scott Bridgman, Why not join and post your own comments?? (email me)