How do I release the PTFE tube?
I would like to print something from FLEX material, so I try to follow the procedure on this site: https://help.prusa3d.com/article/flexible-materials_2057 , unfortunately I can't release the PTFE tube... I don't have the "blue" thing there, mine is black... And it looks like I can't even press it to release the tube... What am I doing wrong?
RE:
pressing the black ring to release your PTFE should work,
That doesn't look like a prusa connector has it been changed already? (maybe they have more than one supplier)
on My MMU1, i found that after a while, the constant side to side movement of the nozzle assembly would cause the fitting to score a groove in the PTFE tube, making removal increasingly difficult until eventually removal was impossible
I never found a good solution to this issue, so I would try and change the PTFE before it jammed, and I kept a stock of fittings on hand, in case I got a jam that I could not clear.
I also kept a spanner on hand, to undo the fitting, if I didn't have time to replace the fitting and PTFE, or couldn't find a new fitting or PTFE.
there are fittings with integral bearings which may have resolved the issue, but the samples I located, were restricted in internal diameter, and would not let filament pass through on the MMU2
the Festo rotary fitting only has a 1.6mm bore (and it's a bit expensive)
Aliexpress also seem to stock a different brand, but I have not had chance to try these
the cost is more acceptable and they do make a 4mm tube, 5mm thread version
regards Joan
I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK
RE: How do I release the PTFE tube?
Thanks for the reply...
I didn't change anything - this is what I received when I bought this printer.
I tried all 5 tubes again, but still no success. And besides, I really can't seem to press the black one, it just won't move.
RE: How do I release the PTFE tube?
Hi Ernicek
Years ago, when I first had my MMU1 I made a small tool to make PTFE removal easier.... I havent got a clue where the STL is now...
BUT i Found this on Printables, which is similar.
https://www.printables.com/model/1034798-ptfe-out 
it's shown with a creality, but should work with a Prusa
regards Joan
I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK
RE: How do I release the PTFE tube?
I found the black plastic fittings PRUSA switched to require over 40KG of force to release the tube. I measured this by putting the fitting with the tube on a scale and using a wrench to press down on the black plastic. PRUSA is not admitting they have a problem with these fittings. The blue fittings reportedly release with simple hand pressure. I do not have a blue fitting so I could not measure the release pressure with the scale.