Low Tank Toilet Repairs

Low-tank toilets

Most low-tank toilets (and by “low” we mean that the tank is not situated 6 feet up on the wall), made prior to 1940 had tanks that bolted to the wall and were connected to the bowl with a short piece of 2″ O.D. tubing. This classic style of toilet flushes as well or better than anything made new today and many people prefer to repair the existing toilet instead of following the often hasty advice given by plumbers to “tear the thing out and replace it!”

Fortunately, parts are available and repair is easy.

Low-tank toilets
diagram shows the basic components of the average toilet tank

The diagram at left shows the basic components of the average toilet tank. There are basically two systems: the flush system consisting of the flush valve, tank ball, and flush lever, and the fill system consisting of the fill valve and float. Many people mistakenly think that these two systems are joined but in fact they work independently of each other. When the lever is depressed, it lifts the tank ball which contains a small bubble of air. The tank ball floats and allows the tank to drain into the bowl through the flush valve. When the water from the tank is gone, the tank ball drops back into place allowing the tank to refill. The float system begins refilling the tank the instant the water level drops, and doesn’t stop until the water level in the tank rises to the fill line. A small portion of the water coming through the fill valve is diverted to the refill tube and directed down the tank overflow. This water runs into the bowl and refills the bowl as the tank is being refilled.

Toilet Tank Troubleshooting

Lever does not stay up when pressed, user has to hold lever down for duration of flush.

Solution: The tank ball or flapper may be waterlogged. Shut off the water supply and hold the flush lever down until the tank is empty. Remove the tank ball or flapper and shake any water out of the air pocket on the underside and reinstall. Examine the upper and lower lift wires or chain for proper alignment. There should be about 1/4” of slack in the linkage. If everything appears OK and the problem re-occurs, replace the tank ball.

Toilet runs continuously, or shuts on and off periodically.

Solution: Remove the tank lid and check the water level. If the water level is to the very top of the overflow tube with water running down the inside of the tube, the fill valve is leaking and needs to be replaced. If the water level is NOT to the top of the overflow tube, the tank ball is leaking. If jiggling the handle stops the flow of water, examine the upper and lower lift wires and guide for proper alignment. Adjust or replace as needed. If jiggling the handle does not stop the flow of water, replace the tank ball. Replace bent or corroded lift wires and guides as well to insure a leak-free repair.

Beyond The Basics

Most prewar toilets used a flush tube to connect the tank to the bowl. Rear-spud tubes (water comes in to rear of bowl) are fairly easy to replace as the tube may be cut to the needed length. Top spud toilets are a little more difficult because different manufactures used different offsets in the flush tube. We have recreated the various offsets made.

(To determine your offset, measure from the top rear of the tube to the wall and then from the bottom rear of the tube to the wall and subtract the smaller number.)

Various offset tubes are available on our Flush ells page. Replacement 2″ slip joint nuts and washers may be found HERE.

Straight flush tubes may be replaced using the 2″ cover casing found HERE.

Offset flush tube for top-spud bowl.
Offset flush tube for top-spud bowl.
Flush ell for rear-spud bowl
Flush ell for rear-spud bowl
47-CT120

Curtin-Style Ballcocks are attached to a 3/8” IPS pipe that runs from the wall and into the tank through a hole or slot in the rear of the tank. The Curtin ballcock includes a stop valve as part of the assembly. Below the stop is a union fitting. If you are extremely lucky, the union thread on the new valve will match the one on your old valve. If not, the old valve will have to be carefully removed from the pipe nipple. Take GREAT care not to break the pipe nipple off in the wall. We suggest soaking the fitting with penetrating oil for several days.

Toilet Bowl Spuds

Toilet spuds are often confusing to our customers because they are sized according the pipe they connect to. The trade size of a spud has no relation to the actual measurements of the spud itself. A 2″ x 2″ spud for example fits a 2-11/16” hole in the toilet bowl and measures about 2-3/8″ across the threaded end. Nowhere does it measure 2″!

All Low-tank toilets like those pictured at the top of the page will use a 2″ x 2″ closet spud. Toilets that have high tanks or flush valves can be other sizes.

Removing A Toilet Spud

Step 1: Loosen the locknut with a large pair of adjustable pliers and back it off until it is on the last couple of threads.
Step 1: Loosen the locknut with a large pair of adjustable pliers and back it off until it is on the last couple of threads.
Step 2: Stike the spud with a wood block or your palm to drive it inward. (Yes, you have to hit it in to make it come out!)
Step 2: Stike the spud with a wood block or your palm to drive it inward. (Yes, you have to hit it in to make it come out!)
Step 3: Remove spud. Very badly corroded spuds can usually be worked back and forth until the rubber washer disintegrates and removed. In serious cases, the spud can be cut off with a hacksaw.
Step 3: Remove spud. Very badly corroded spuds can usually be worked back and forth until the rubber washer disintegrates and removed. In serious cases, the spud can be cut off with a hacksaw.

Maddock Spuds

Maddock Spuds

The earliest washdown bowls made by Thomas Maddock from about 1906 to 1915 used a spud with locking ears that engaged a screw-thread-like groove in the porcelain. “Standard” bought the Thomas Maddock & Sons company and carried the design in some of their own toilets, finally phasing them out by 1920. The Maddock design, though not bad, is not as reliable as the expansion-type spuds that replaced them.

Photo shows a Maddock spud with locking ears and the corresponding slot in the bowl.
Photo shows a Maddock spud with locking ears and the corresponding slot in the bowl.
We recommend applying a bead of silicone to the in-facing side of the gasket on a Maddock spud before installation.
We recommend applying a bead of silicone to the in-facing side of the gasket on a Maddock spud before installation.
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