Help when the lid again on strike!

The Thermos is wonderful!
When the lid is no longer Plopt you can gently with a
small screwdriver or similar at the edge of the inner side
pry it can then be easily opened like a Tupperware container.
There are then 3 parts: The lower lid, the shell and the pressure -
Button.
All parts soak in lukewarm Spüliwasser and soft with a
Clean brush, time and again the transparent cylinder Plop-
press as accumulate in this coffee or ev. and tea deposits
Block lead.
If the Ploppi then pops back, the lever must only in the
upper lid can be placed (pay attention to the guide!)
And then the whole lid like a Tupperware container with compliance with the
Plastic tabs (it is only in a position!) Compressed
will.
I use the pot every day and always when the lever clamps
I do this procedure (every 1 - 2 years) so the pot will last forever !!
LG. Thomas