Since the Ender 3 is a bowden extruder, which means the main extruder motor is mounted to the frame and not to the hotend. And the filament is fed trough an PTFE tube to the Hotend. My printer was struggling a lot of extrusion problems. Therefore i decided to exchange the PTFE Tube from the Standard tube to a quality one from Capricorn.
Advantages of the Capricorn PTFE tube
There are mainly two advantages in exchanging your PTFE tube. The first one is to reduce the friction between the Tube and the filament, this should make it easier to extrude the filament.
The second reason is the PTFE Tube wears out over time inside the hotend, this is due to the high temperature.
Thermal Paste Mess
After I received the replacement tube i unscrewed installed tube from the Hotend. There I discovered the mess. The heatbreak sits just press fit inside the cooling block, to maximize the heat transfer it is covered in thermal paste. Unfortunately the old thermal paste went from liquid to something like chewing gum like texture .
There was no way to get rid of the old thermal paste, than disassembling the whole hotend.
Ender 3 Hotend Assembly/ Disassembly
First of all you have to unscrew the whole fan duct, part cooling fan and cover to access the hotend. Then you should be able to screw out the PTFE coupling with the tube stuck inside. The next part is too loosen the screws that hold the thermocouple and the heating element inside the heating block. The screw holding the heating element is screwed in for the bottom of the heating block. Now that everything is off the hotend you can loosen the two screws that fix the hotend to the sliding carriage.
Since I had to clean the whole Hotend I took it apart even further. Therefore i unscrewed the two screw that sit inside the heating block and screw into the red cooling element. After that you can unscrew the heat block from the heatbreak using a little bit of force. I had to use some pliers to get it off. The last thing is now getting the heatbreak out of the cooling block. Therefore unscrew the little headless screw and apply some force to pull the heatbreak out of the cooling block.