When using any PTFE heatbreak the PTFE tube itself is responsible for creating the seal between the tubing and the nozzle.
Assembling a hotend with a PTFE heatbreak is like an all metal one except you will need to make sure the PTFE tube has pressure on the back of the nozzle to seal correctly.
- Install the nozzle all the way into the heaterblock
- Back the nozzle out 1/4 turn from the heaterblock
- Install the heatbreak into the heaterblock until it hits the back of the nozzle
- Install the assembled heatbreak+heaterblock+nozzle into your hotend heatsink
- Unscrew the PTFE fitting from your hotend 1/2 a turn*
- Make sure your PTFE tube is cut squarely and flat
- Insert the PTFE tube all the way into the hotend until it stops
- Tighten the PTFE fitting down all the way*
- Heat the hotend to 240C
- Tighten the nozzle down with a wrench with the force of 1 finger (do not over tighten)
* If you have an E3D Hotend or one that does not have a screw in type PTFE fitting unscrew the nozzle 1/2 a turn instead of the fitting. The nozzle will need to be tightened back when the nozzle is at 240C.