this image shows what way-too-much lube on the driver looks like
clean all the working surfaces fully with an effective solvent that does not leave an oily residue, leave to evapourate, relube the o-rings with just a sheen of lube so they dont grab in the bore
as you can see from the image i relubed the entire head of the driver – this revealed itself to be an error
if you do as i did and coat the entire head of the driver, and the spring, and the bore that the driver runs in you will discover, as i did, the result will be that the toggle(s) are a bit sloppy for a while when you first return them to the resting position as the driver has not been fully driven back out by the spring behind it
if this happens you will have to do as i did and start again – learn from my mistake!
i suspect in an ideal world a silicone lubricant of lower viscosity might also be preferrable on this particular component
UPDATE: having spent another couple of hours re-doing the above steps two more times, as a result of the driver not snapping back and tensioning the toggle i am not convinced that my initial assessment (above) is correct. i am now of the view that the two o-rings on each driver have swollen from the heat over the last 18 months of service, having been on pretty much every day for never less than 12 hours and often much more.
i need to confirm my suspicions with the manufacturer on monday, but its about the only explanation i can think of as it is such a beautifully simple system.
i can see when i take the end caps off, as i have now done numerous times tonight, that the drivers are binding in the bores to the extent that i need pliers to pull the drivers out of the bores (put a rag over the soft brass drivers if you use pliers or you will damage the drivers with the pliers).
the bores are clean, the o-rings are lubed, but they seem to be a bit swollen and are certainly not pulling down tight into the o-ring grooves as new o-rings of the correct size would. i think it might be time for these o-rings to be replaced.
those of you who have puchased the full service kit will find these o-rings in that kit
UPDATE II: im sure i have some spare drivers at the factory that are unused and i can compare the snug-ness of the o-ring fit and bring them home and swap them out for the ones i am currently using an see if this cures the problem. these are the sorts of things i enjoy blogging about as i hope it will be of real value to you wherever you might be on the globe with your LONDINIUM I. hopefully by now we have an answer for almost anything that can possibly go wrong with a LONDINIUM lever espresso machine. You raise your question on the owner’s forum and we post the answer there so we only have to answer any given issue once. In this was we can generate efficiencies and build a repository of information for you to quickly search at any time of the night or day.