Cold Pulls

Cold pulls are a fast way to clear partial nozzle clogs: heat to melt and flush, cool into a “rubbery” window, then pull the filament so it drags burnt plastic and dust out of the melt zone. Done correctly, the pulled tip shows a sharp nozzle-shaped imprint and extrusion returns to smooth, steady flow.

TL;DR

If you have under-extrusion or extruder clicking from a partial clog, do a cold pull: flush at print temp, cool to the pull-temp window, then pull in one smooth motion and repeat until the tip comes out clean.

Cold PullsTopic-specific diagram for the concept, checks, and tradeoffs in this lesson.Heat to print tempExtrude 20–50 mmCool to pull tempPLA ~90C, PETG ~120CSteady pullOne smooth motionInspect tipNozzle shape, specks?RepeatUntil cleanReheat & extrudeConfirm smooth flow
A step-by-step diagram helps learners hit the correct temperature window and sequence (heat, flush, cool, pull, inspect, repeat) without requiring motion.

What a Cold Pull Fixes (and What It Doesn’t)

Cold pulls work best for partial clogs and contamination in the melt zone: charred plastic, pigment bits, dust, or residue after a small jam. They usually will not fix a fully blocked nozzle, a kinked Bowden tube, a loose/worn drive gear, incorrect extruder tension, a failing hotend fan (heat creep), or a gap/leak in the hotend assembly.

What You Need

  • Pull filament: nylon is ideal; clean PLA often works
  • Side cutters to make a clean, square filament end
  • Printer controls to heat and manually extrude/retract
  • Optional: tweezers or a brass brush to clean the outside of the nozzle

Pick the Right Pull Temperature Window

The goal is a semi-solid “rubbery” plug that grips debris but still releases from the nozzle. Start with these ranges and adjust in small steps if needed: PLA 85–100 C, PETG 110–130 C, Nylon 130–160 C. If it won’t budge, you’re too cold; if it stretches like taffy and leaves strings, you’re too hot.

Cold Pull Procedure (Direct-Drive)

  1. Cut a fresh, clean tip on the pull filament. If the current filament is dusty/brittle, unload it first.
  2. Heat to the normal printing temperature for the pull filament and manually extrude 20–50 mm to flush melted plastic through the nozzle.
  3. Cool down to your pull-temperature target and wait until the hotend stabilizes there.
  4. Apply straight, steady upward tension on the filament. If it will not move, increase temperature by 5–10 C and try again.
  5. When it releases, pull in one smooth motion. You want the plug to come out as one piece.
  6. Inspect the tip. A good pull shows a sharp nozzle-shaped imprint; dark specks or streaks mean you removed debris.
  7. Repeat until the plug comes out consistently clean (often 2–5 pulls).
  8. Reheat to normal printing temperature, extrude 20–50 mm, and confirm the flow is steady. Then reload your normal filament.

Bowden Setup Notes

  • Release the extruder idler or disable the extruder motor so you’re not fighting the drive gears while pulling.
  • If the tube grips filament or the path has too much friction, disconnect the Bowden tube at the hotend and pull directly.
  • When reconnecting, fully seat the tube against the nozzle/heatbreak interface (depending on your hotend design). A poorly seated tube can create a gap that traps molten plastic and causes recurring jams.

If It Doesn’t Work

Filament snaps during the pull

Likely cause: Too cold; brittle filament; tight bends/friction in the path

Fix: Raise pull temp 5–15 C; switch to nylon or fresh PLA; straighten the path or pull with the tube disconnected

Filament will not release at all

Likely cause: Too cold, or a severe/solid blockage

Fix: Increase temperature in 5–10 C steps; if still stuck, remove the nozzle for cleaning/replacement and inspect for heatbreak plugs

Pull comes out clean but extrusion is still weak

Likely cause: Extruder issue, heat creep, or a restriction above the melt zone

Fix: Clean the drive gear, verify idler tension, confirm the hotend fan is running, and try another flush + pull

Debris returns quickly after a successful pull

Likely cause: Dirty/wet filament, printing too hot, or burnt residue after earlier jams

Fix: Dry and clean filament, reduce print temperature slightly, and perform additional pulls until plugs stay clean