=148. Faucets.= Faucets are made in different patterns, but they need practically the same care (Fig. 77). The leather, or rubber, washer in a faucet must be renewed when it leaks. To renew the washer, unscrew the cap from the faucet. Remove the valve. Take off the ring of packing. Replace with a new ring, and put the faucet together again. The only tools needed for this repair work are a wrench and a screwdriver. Shut off the water from the pipe to the faucet before beginning to repair a leaking faucet. [Illustration: FIG. 76. Water tank and heater.] =149. Valves.= Valves are constructed much like faucets. They, too, sometimes need repacking. Follow the directions for repacking of faucet (Fig. 78). [Illustration: FIG. 77. Faucet showing parts.] [Illustration: FIG. 78. Radiator valve.] =150. Overflows.= Keep overflows clean. When the plug and overflow are combined, as they sometimes are, lift out the cylinder forming the plug and overflow and wash it. When it fails to hold water in the tub or basin, it may need a new washer on the lower part. This may be replaced very easily. Fig. 79 shows one type of overflow. [Illustration: FIG. 79. Cross-section of overflow on bath-tub.] [Illustration: FIG. 80. Plumber's pump.] It is more difficult to keep other overflows clean. They may be flushed or cleaned with a brush attached to a wire. =151. Traps for Bath Tubs and Basins.= Dirt and slime collects in traps. Clean them frequently. Always leave clean water in the traps of bathroom fixtures and sinks. Only matter quickly soluble in water should pass into drain pipes. Keep matches, hair, sweepings, rags, fruit skins and stones out of the fixtures. If the drain from a basin, sink or tub fails to carry away the water, the stoppage may be removed with a small plumber's pump (Fig. 80). This is a small rubber cone-like device which is placed over the outlet to the drain and moved up and down so that it sucks air, water and whatever may be movable up the pipe. CHAPTER XXI CESSPOOLS, SEPTIC TANKS AND CITY SEWER SYSTEMS =152. Relative Value of Cesspool and Septic Tank.= Sewer pipes for private water systems usually drain into cesspools or septic tanks (Figs. 81, and 81-_a_). The waste goes thru a process of decomposition before passing out into the soil. Sewage should both liquify and oxidize before entering into the soil. Oxidation purifies liquid sewage so that it is not contaminating. If oxidation is not brought about in the cesspool or septic tank, sewage, which is fresh, should be run onto the surface of the ground where the air and bacteria for oxidation can be found. Cesspools are not as good as septic tanks because there is not the surety of sewage being oxidized in them, as there is in the septic tank. They lack oxidizing chambers. [Illustration: FIG. 81. Septic tank and tile.]