Hi,
I’m trying to get my first clog cleared and have tried everything. I’m really disliking this nozzle/hotend unit as a result. My hot end is completely blocked and filament is stuck in my extruder. I tried pulling the PTFE tube (while pushing the collar lock thing) and am completely unable to remove it. Any advice would be appreciated.
Thanks,
Chad
Never mind, I managed to get it off but I damaged the tube in the process. Oh well. Glad it had extras. 
We have hundreds if not thousands of this type of fittings at work. I find that pushing on the release ring with a tool, whether it’s a 3D printed one like this or a open end wrench that just fits the tube, and then pushing the tube into the fitting before pulling on it will sometimes get the fingers to let go of the tube. If it’s just the end of the tube that’s damaged, we just cut that part off and reuse the tube.
since I had to deal with this recently aswell because of a nozzle swap: I ended up unmounting the extrusion gearbox and taking out the fitting with the PTFE tube still attached (because I could not get it released obviously). Once I had the fitting with the PTFE tube in my hand, I simply pushed the remaining PTFE tube through the fitting and that was it. The fittings “teeth” seems to have made the PTFE tube stuck with no way getting it out other than I explained above. I’ll just leave this here for the future
Yeah, I was using a tool, but couldn’t get the teeth to disengage. And yeah, I used some pliers to get a grip on the tube while using the other tool to push the collar lock bit. I wound up damaging the tube and just cutting it back a bit. Didn’t wind up dipping into the extra tubes yet in the end.
The key part of my method is to push the tube into the fitting while pushing the lock collar then pulling it out of the fitting. It doesn’t always work but it does often enough that it’s the first thing I try on a reluctant fitting. I’ve had some that were so bad, I just cut the tubing and replaced the fitting. We have operators that have enough grip strength to pull the guts clean out of a fitting and tell us “it just fell apart”.
I thought mine might “just fall apart” given the effort it took. 
I just remembered we have one of these sitting around at work because we use 1/4" and up tubing and it won’t fit. It may need to live at my house!
I had the same problem.
The cause were little filament particles broken down in the extruder.
I used YouTube videos, but can’t post them here, so I’ll post the videos ID’s:
Take the extruder out of my P1S:
hCu8wecNmWY
Then this:
M1CbaILC2vV2Qzdr from 4:53
Showed how to take apart the sensor, which helped to release the tube out (finally).
Last, this video:
CLlT1RV-oJE
was the one that I really needed to clear the filament.
Hope this helps someone in the future.
thank you for your comment! the second video you posted doesn’t exist anymore, any chance about any other similar video? many thanks 