6 Reasons Your Filament’s Leaking During Automatic Bed Leveling

Professionals and amateurs create models, prototypes, novelty objects, and toys using 3D printers. They construct the model gradually by adding layers of molten or melted filament to a print bed. Since it began being widely used, this technology has advanced significantly, yet it still has problems, such as leaking nozzles.

Due to improper assembly or an excessively high extrusion temperature, 3D printer nozzles may begin to leak. Additionally, faulty adjustments, damaged hardware, and a dirty nozzle may result in leaks. 

In this article, we’ll dive more deeply into some of the causes of leaking filament.

Common Causes & their Fixes

Incorrectly Assembled Nozzle

The wrong assembly of the nozzle is among the most common causes of a filament leak. Unfortunately, inexperienced 3D printer hobbyists who may not be as familiar with the setup frequently experience this issue.

The nozzle is likely to blame for leaks if you put the printer together without following any of the instructions or, if it was pre-built and you neglected to verify everything.

Many 3D print users struggle with the same challenges, so it’s not just amateurs who have this difficulty.

Related: How to Upgrade Your Ender 3 Nozzle?

You should detach and reinstall the nozzle if you believe that it is the source of the issue. Just keep in mind to be careful, as several internal components are fragile and prone to breaking.

A 3D printer nozzle can be taken out and reinstalled as shown in the steps below:

  • Remove the tip and the heat break from the heat block to separate the nozzle.
  • Ensure that everything is in working order by inspecting it for damage or cracks.
  • Insert the short end of the heat break into the heat block since most heat breaks will have a space along the tube.
  • Avoid tightening the heat break into the heat block too much.
  • A small space should be left between your nozzle and the opposite end of the heat block as you insert it.
  • The heat break must be tightened into the heat block until it comes in contact with the nozzle from the inside.

High Extruder Temperature

High extrusion temperatures are another common reason your 3D printer may be leaking filament.

Different materials heat up at varying temperatures. Therefore, you might need to tweak your settings for the proper level of heat based on the type of material you’re printing.

Leaky nozzles and stringy models are both symptoms of high heat.

Firstly, check that everything matches up by checking the recommended nozzle extrusion temperature of your selected material. Additionally, don’t forget to adjust the temperature whenever you change materials.

Examining the temperature graphs in the console of your choice is another thing you can do to diagnose the problem. You might have a heating issue if the charts are crooked or unequal, which would result in leakage and stringy prints.

Nozzle Unable to Retract the Filament

Stringing is a common leaking issue that frequently arises when using a 3D printer. This occurs as the nozzle moves from one print spot to the next while extruding plastic. Normally, filament should not be extruded during this operation otherwise, the print will appear to have strings or webs on it.

In order to avoid dripping or stringing, the nozzle will often retract a small amount of the melted plastic as it passes from one place to another. You’ll probably see leaks at the nozzle if your 3D printer is not configured to retract.

Fortunately, there are several solutions if you run into stringing issues. Even though you might assume that deactivating the extruder will do the job, that is more likely to make things worse. Therefore, you might want to double-check the retraction parameters and modifications before proceeding with your print.

Stringing is a likely result of not using retraction when you start to print. As a result, applying only a modest amount of retraction should result in a smoother and stringless design. Melted material doesn’t always return to the nozzle during retraction. Instead, it releases pressure from your nozzle, keeping the plastic from leaking out while it readjusts.

Related: How Often Should You Change Your Nozzle?

  • Review the file to find out what it says about retracting, as the splicing software should set retraction automatically. If the box is not checked, the leak is probably due to that.
  • Retraction should always be set to “yes” or “on.”
  • Check to see how much material the nozzle is retreating if retraction is on and you’re still encountering leaks or stringing.
  • For instance, adjust the setting to 4 or 5 mm if the retractor leaks between moves when it is set to 3 mm. Generally speaking, 5 mm is a great place to start. From there, make adjustments just 1 mm at a time until you achieve the desired results.
  • Check your filament to be sure; some filaments can even require 7 mm of retraction.

Preheated Nozzle

The start of your print may show an odd amount of leakage in your model, but once it starts going, it prints normally thereafter. That may occur as a result of the nozzle becoming clogged with extra extrusion.

Due to advancements in technology, that might not be an issue for more recent models, but with some older 3D printers, you might need to prime or pre-heat your machine.

Nozzles frequently contain a small quantity of extra plastic. However, if your print starts to leak before your model even starts, you probably need to prime the nozzle.

You may prevent leaks by priming or preheating your nozzle before you start printing. When selecting what temperature and for how long to prime your printer, you might need to verify the datasheet and model of the 3D printer.

When adjusting temperatures, always read your instructions and make sure your heat box or nozzle isn’t getting too hot.

Alternatively, to use up any unused filament, simply print a broader bed or skirt around your model. When the design is finished and cooled, this is snapped off.

Dirty Nozzle

Your prints will stay sharp and smooth if your 3D printer nozzle is cleaned on a regular basis.

A dirty nozzle is likely to cause a variety of issues, such as leakage or clogging. You might also notice that the nozzle is not taking up materials or that there are missing layers.

Your prints may appear uneven or sloppy because too much or too little material may slip out.

Of course, having a smooth pattern is crucial if your models are for PPE medical purposes. However, even amateur printers want their prints to look excellent.

You might encounter these issues and potentially harm your machine if you don’t remove your nozzle and clean it.

The good news is that you can clean your nozzle in a number of different methods, including:

By manually inserting a piece of filament into your extruder, you can clear the obstruction.

Use a tiny needle to remove the obstruction.

With a fresh filament, try a cold pull.

Related: Are 3D Printer Nozzles Universal?

In order to perform a cold pull:

  • If your extruder has a Bowden tube, take it out.
  • Heat the nozzle to the highest the printer will allow it to be heated, or at the very minimum hot enough to melt the two filaments (the clogged filament and the material you’ll be using to push it out).
  • Put one end of a strip of nylon or similar filament into the heated nozzle.
  • Bring the temperature down to zero after you notice filament spilling out.
  • Push the substance until it stops dripping.
  • Allow the filament and nozzle to cool.
  • Reheat the nozzle before removing the nylon or filament, which should be stuck to any clogged residue.
  • Repetition may be required.

Coaster Adjustment Issues

3D printers are fairly tricky to use. These high-tech machines can produce some fascinating and significant models. However, if you use one of these printers, you may have some configuration tweaks that are causing some spillage.

Before dismantling your device, make sure you check your owner’s manual to confirm that your temperatures and retraction are set correctly. If it is simply a minor configuration adjustment, it can save a lot of time and effort.

The coaster adjustment is one of the options. It can be used to repair issues, including stringing or leakage. It can also make the model’s surface smoother.

The first step is learning how to use the function. Then, run a test print to avoid errors and verify the appropriate settings. 

  • Set the coaster to 0.064 and run a few test prints to try these values before deciding on what volume to go with. 
  • Make sure the minimum coasting level is set at 0.08. One great thing about 3d printing troubleshooting is the fact that you can customize it according to your requirements.  

Frequently Asked Questions

What is the Best Nozzle Temperature for PLA?

Although it is quite adaptable and can function effectively anywhere between 180 and 230°C (356 and 446°F) PLA prints best at about 210 °C (410°F).

What is the Best Retraction Speed for PLA?

On direct drive extruders, materials like ABS and PLA will perform well at speeds of 40 to 60 mm/s and retraction distances of 0.5 to 1.0 mm.

What Happens with Too Much Retraction?

Little gaps or even blobs develop from excessive retraction because of air pockets inside the print head.


3D printers are an effective method for producing prints and models, and a number of companies are already utilizing them to build personal protective equipment (PPE) for medical purposes.

It is a rapidly evolving technology that is being embraced by the masses for all sorts of utilities, from mechanical equipment to decoration pieces.

Nevertheless, rapid advancements in 3D printing come with their own set of issues, one of which is a leaking filament.

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