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  1. This guide will take you through the entire process of how to disassemble the MK3S/MK2.5S/MMU2S extruder, replace the PTFE tube and assemble the extruder back. Note that the upper part of the MMU2S extruder is slightly different from the single material MK3S/MK2.5S, but the disassembly is the same as it focuses on the lower part.
    • This guide will take you through the entire process of how to disassemble the MK3S/MK2.5S/MMU2S extruder, replace the PTFE tube and assemble the extruder back.

    • Note that the upper part of the MMU2S extruder is slightly different from the single material MK3S/MK2.5S, but the disassembly is the same as it focuses on the lower part.

    • This guide doesn't work for the MK3/MK2.5 type of extruder!!! See the How to change a PTFE tube - MK3/MK2.5

    • To obtain the new PTFE tube, you have two options:

    • Buy cut and chamfered PTFE tubes from our eshop

    • Make your own PTFE tube using this guide: How to trim PTFE tube - Original Prusa i3 printers

  2. Please prepare the following tools for this chapter:
    • Please prepare the following tools for this chapter:

    • 2.5mm Allen key for M3 screws

    • Needle-nose pliers for zip ties (optional)

    • Pliers are not needed, but in some scenarios, you might need them to cut the zip ties.

    • Apart from the mentioned tools, it is recommended getting a bowl or a small box for the screws and parts you will remove during the disassembly, you will need them later.

  3. Before you start it is recommended to protect the heatbed! Use any cloth or piece of fabric, which is thick enough and cover the heatbed. This will ensure you won't damage (scratch) the surface during the disassembly.
    • Before you start it is recommended to protect the heatbed!

    • Use any cloth or piece of fabric, which is thick enough and cover the heatbed. This will ensure you won't damage (scratch) the surface during the disassembly.

    • Make sure that:

    • the filament is unloaded from the hotend (remove also the spool and the spool holder)

    • the printer is properly cooled down

    • the printer is unplugged from the socket

    • X-axis with the extruder is slightly above the middle of the height (Z-axis) of the printer.

  4. In this guide, we won't disassemble the extruder completely. Thanks to the new design it is enough to release the screws and move the plastic parts slightly apart. Release and remove the M3x14 screw from the hotend fan. Release and remove the M3x20 (M3x18) screw from the hotend fan. Note that the fan-shroud might fall off.
    • In this guide, we won't disassemble the extruder completely. Thanks to the new design it is enough to release the screws and move the plastic parts slightly apart.

    • Release and remove the M3x14 screw from the hotend fan.

    • Release and remove the M3x20 (M3x18) screw from the hotend fan. Note that the fan-shroud might fall off.

    • Leave the other two screws holding the hotend fan in place. No need to remove them.

    • Release both screws, but don't remove them. We will use them to hold the extruder parts together.

    • Release both screws, but don't remove them. Just make sure they won't block the motor from moving.

  5. Before you move any parts, make sure there is enough slack in the extruder motor cable!!! If not, you have to cut the zip ties on the textile sleeve, open the box with electronics and make sure the motor cable is free to move. Carefully move the extruder apart. First, pull the motor, then the lower part with the print fan.
    • Before you move any parts, make sure there is enough slack in the extruder motor cable!!!

    • If not, you have to cut the zip ties on the textile sleeve, open the box with electronics and make sure the motor cable is free to move.

    • Carefully move the extruder apart. First, pull the motor, then the lower part with the print fan.

    • Create a gap similar to the picture. Align the printed part holding the motor with the edge of the fan frame.

    • Reach for the hotend and incline its upper part towards the motor, it should slide out.

    • If the hotend is still stuck inside, release the screws more and increase the gap between the printed parts.

    • BE EXTRA CAUTIOUS with the hotend cables!!! You can break them! Use a small force to pull the hotend out. Don't bend the cables.

  6. For the following steps, please prepare:
    • For the following steps, please prepare:

    • PTFE tube for MK3S/MK2.5S/MMU2S (1x)

  7. No need to place the hotend in the horizontal position like in the picture. It is better to leave the hotend next to the extruder.
    • No need to place the hotend in the horizontal position like in the picture. It is better to leave the hotend next to the extruder.

    • Press the black plastic collet.

    • Remove the PTFE tube from the hotend.

    • Throw this old tube immediately to the nearest trash bin to avoid installing it back by accident ;)

  8. Now it is time to insert the new PTFE tube. Note, that each end of the tube is different. One end of the tube has "rounded" outer edge. This end must be inside the hotend.
    • Now it is time to insert the new PTFE tube. Note, that each end of the tube is different.

    • One end of the tube has "rounded" outer edge. This end must be inside the hotend.

    • Look at the other end, where the tube is drilled inside, the shape of the edge is "conical". This is the side, where filament enters the tube. This part must be outside the hotend.

    • Push the black collet in. Slide the tube all the way in and hold it!

    • Using the other hand pull the collet out and only then release the tube!!! THIS IS CRUCIAL for the hotend to work properly.

    • After you finish inserting the new PTFE tube, check all the parts are properly tightened and nothing got loose during the process.

  9. Place the hotend back inside the extruder. Ensure the orientation is the same as in the picture with cables on the left side. IT IS CRUCIAL to ensure the hotend fits to the extruder-body!!! The printed part is shaped according to the hotend. See the second and the third picture! IT IS CRUCIAL to ensure the hotend fits to the extruder-body!!! The printed part is shaped according to the hotend. See the second and the third picture!
    • Place the hotend back inside the extruder. Ensure the orientation is the same as in the picture with cables on the left side.

    • IT IS CRUCIAL to ensure the hotend fits to the extruder-body!!! The printed part is shaped according to the hotend. See the second and the third picture!

  10. Check once again the correct position of the hotend. Look from below the extruder. The heater block should be oriented, like in the picture. Take a look from the side of the extruder. The nozzle should be slightly below the printed fan-shroud.
    • Check once again the correct position of the hotend. Look from below the extruder. The heater block should be oriented, like in the picture.

    • Take a look from the side of the extruder. The nozzle should be slightly below the printed fan-shroud.

  11. Carefully and slowly push all the parts together. In case of any significant resistance STOP immediately and check, which part is blocking the movement .
    • Carefully and slowly push all the parts together. In case of any significant resistance STOP immediately and check, which part is blocking the movement .

  12. Tighten both screws, but ensure no cable is pinched on both sides of the extruder. Similar for the front side. Tighten both screws. Ensure no cable is pinched. Put back the M3x14 screw and tighten it.
    • Tighten both screws, but ensure no cable is pinched on both sides of the extruder.

    • Similar for the front side. Tighten both screws. Ensure no cable is pinched.

    • Put back the M3x14 screw and tighten it.

    • If you have removed the fan-shroud, put it back in. Then fix it in place with the M3x20 (M3x18) screw.

  13. Great job! You've just changed the PTFE tube in the extruder. Heat up the printer and try it out ;)
    • Great job! You've just changed the PTFE tube in the extruder.

    • Heat up the printer and try it out ;)

Finish Line

23 other people completed this guide.

Jakub Dolezal

Member since: 02/20/2017

225 Guides authored

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Prusa Research Member of Prusa Research

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6 Comments

Is there a guide like this for the MK3S?

Tim Graupmann - Reply

Hello Tim,

This is a guide for MK3S. For the MK3, it can be found here:

How to change a PTFE tube - MK3/MK2.5

Marcin M. - Official Prusa CS -

An excellent guide. Thank you for doing this. It was long overdue for the MK3S.

Doug Dobson - Reply

are the pre-cut / shaped PTFE tubes available for sale? I couldn’t find them in the shop

Derek Bosch - Reply

Hi Derek,

Yes, they are. You have to be logged in to be able to see them. If you have purchased your printer from a 3rd party, please contact us and we will enable access for your account.

Marcin M. - Official Prusa CS -

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