My RSST's leaked down the center shaft to the bottom pin as well as leaked down to the bottom plate under the
tank. Two fixes have curtailed the leaking. 1) an oring under the spring which acts the same as the washer fix, and 2) take a carto condom and cut to about 1/8" in height, poke a hole in it with your center tube, slip over the top of the center of the
tank (this will channel any leaking
juice that would leak into the bottom plate back into the tank).