In the following steps we will be constraining the filament path within your hot end to ensure smooth movement and operation when melting 1.75mm filament.
1) Disassemble the print head by removing the 4 screws on the top of your hotend. This will expose the hotend section as shown in the photo below.
2) Caution: this next step will require you to heat up your unsecured hotend. Please make sure you do not directly touch the hot region of the hotend. Using the Ultimaker menu, heat up the hotend by selecting Maintenance > Advanced > Heat up Nozzle > 210C.
3) Once the temperature reports a reading of 210C, carefully slide and press the short hotend ptfe sleeve into the print core taking care not to apply excessive force. While pressing the sleeve into place you may have molten filament press out of the nozzle and if you find you are unable to fully seat the Teflon sleeve as shown in the photo please, perform a cold pull and repeat this step.
4) Using the Ultimaker menu cool down the hotend by selecting Maintenance > Advanced > Heat up Nozzle > 30C.
5) Once the temperature reports a reading of 30C please reassemble the printhead assembly.
6) With the hotend reassembled, please press the white bowden tube installed in Step 1 as far down as it will go so that it is able to mate with the top of the Teflon sleeve insert. You may need to twist the tube while applying a light downward force to help guide it deeper in. It is critical that the bottom of the bowden tube mates with the top of the newly installed Teflon sleeve as it will secure it in place and prevent print defects from a shifting Teflon sleeve.
Please Note: 90% of reported performance issues with this 1.75mm adaptor relates back to step 6 above. If the bowden tube is not seated firmly to mate with the hotend sleeve, the system will not work properly. Please double check that step 6 above has been completed properly.