Occasionally a tap will continue to drip even after being fitted with a new washer. This indicates the valve seating has been scratched and scored by grit in the water supply and no longer gives a watertight connection. There are reseating tools available, but the simplest way to deal with this problem when it affects a conventional tap is to use a new nylon washer and seating kit. The nylon seating is placed squarely on the brass seating of the tap. Put the new washer and jumper in the headgear of the tap and screw them down hard into the tap body, forcing the nylon valve seating into position. This method cannot be used on Supataps, but the manufacturers of these taps make and supply a reseating tool for the purpose.
Gland failure
Another common fault in taps, gland failure, is indicated by water escaping up the spindle when the tap is turned on. The tap can also be turned on and off very easily, with just a spin of the fingers, which often causes water hammer (the effect of shock waves in the pipes produced by the sudden cessation of flowing water). Causes of gland failure may be back pressure resulting from the connection of a hose or detergent-charged water running down the spindle and washing grease from the gland packing. To adjust or renew the gland of a conventional tap, remove the capstan or crutch head by unscrewing and removing the tiny retaining grub screw.
If taking off the head proves difficult, open up the tap and unscrew and raise the protective cover as high as possible. Insert two pieces of wood (at back and front) between the base of the raised cover and the body of the tap. Then close the tap down again and the upward pressure of the cover will force off the head or handle. The gland-adjusting nut is the first nut through which the spindle of the tap passes. To tighten, tum in a clockwise direction.
Eventually all the allowance for adjustment will be taken up and the gland packing will have to be renewed. To do this, unscrew. and remove the gland packing nut. Existing gland packing material can be removed with the point of a penknife. Repack with strands of wool steeped in vaseline, press down hard and reassemble the tap. Some modern taps have a rubber ‘O’ ring seal instead of a conventional gland. These are less likely to give trouble, but if they do simply renew the ring.