I've been wondering about the intended function of the piston seals on my L1.
It seems obvious that the bottom seal (closest to the shower screen) keeps air and water from escaping upwards when spring pressure is applied to the piston.
However I'm not so sure about the two seals above that which face towards each other across the channel in which the circular ptfe ring is situated. I presume that the four holes in the group sleeve emit thermosyphon water which remains in this channel until the lever is pulled down. The purpose of these two seals would be to retain that water until the holes are completely uncovered by the rising piston and, secondly, to act as a stabiliser for the piston as it rides up and down the column.
yes, the upper two seals prevent the water from the preinfusion circuit (under pressure) from travelling up or down from the four inlet holes when the machine is idle
when the top seal is toast water leaks upwards past the seal and comes out the hole in the back of the group top; when this occurs it is important to replace the seal promptly as the spring is now immersed in water and will rust quickly if it is left in this state
Thanks, Reiss. I replaced the lower seal yesterday because the lever was catching higher than usual. That cured the problem. I was not worried about the upper seals because they looked OK, if a little worn, but I’ll keep an eye out for leaks.
The new R-24 seems a very refined evolution of the previous tank-fed versions. Congratulations!