How to Restring a Dewalt Weed Eater

Dewalt weed eaters feature trimmer heads that use nylon lines to cut weeds and grass in hard-to-reach areas around a lawn or landscape. They are light-weight and ergonomic, with features like the QuickLoad spool head that allows for fast and easy reload of the cutting line without disassembly. Other models like the Dewalt 40V weed eater has the Quick Feed spool feature which allows for fast and easy reloading of line with a twist of the cap.

With time, your weed eater string will need to be replaced. This is because the cutting line on the trimmer breaks down as you use it. The string will cut down weeds and grass, and it breaks just a little bit every time it strikes something on the lawn. You could run out of string at any time.

Restringing a weed eater is not hard, contrary to what some people might believe. You just need to know a few basics and you would be good to go.

How you replace the line on your Dewalt weed eater can vary depending on your model. For example, while some Dewalt trimmers have the traditional bump, others like the DCST920, DCST970, and DCST991 feature the new QuickLoad spool head that allows you to reload the cutting line fast and easy without disassembly.

You can easily differentiate the head type by looking at the spool itself. The QuickLoad has a flat bottom while the traditional bump has a traditional bump knob.

Signs That Your Dewalt Weed Eater String is Old and Needs Replacement

It is normal for the cutting line to wear down as you use it, but the trimmer line can wear faster than you expect if you are cutting tough or thick weeds, if you are cutting against hard surfaces such as rocks and walls, or if the line is spinning too fast.

The old cutting line can become brittle and prone to breaking. If your line is over 5 years old and breaks often, replace it.

Another sign is when the cutting line advances too much. Each automatic feed and bump feed string trimmer has a small blade set into its guard that prevents the cutting line from getting too long. That blade eventually gets dull, and it can sometimes break off. In either case, the line feeds out farther than you expect, possibly slicing into fences or flowerbeds. Fortunately, replacing a dull or broken cutting blade is not hard.

Start by checking your string supply. If there is very little left, this is a sign that you should have it replaced. If you have quite a lot of string left, you may still want to take it out and restring it if it has come loose or been damaged.

Next, make sure you are choosing the right string. String trimmer line comes in a range of thicknesses. For light work, such as trimming grass, 0.065 inches to 0.085 inches should be sufficient. For thicker grass and weeds, a line in the 0.085 inches to 0.110 inches range will get the job done, and for thicker underbrush, anything thicker than 0.110 inches will work.

Most importantly, be sure to use the manufacturer-recommended weed eater string size. The size can vary depending on the brand and model. Using other sizes may degrade performance or damage the trimmer.

How Often Should You Restring Your Dewalt Weed Eater?

There are things that can affect how long a weed eater string lasts, and consequently the frequency of restringing:

Trimming Techniques

Using a weed eater properly is the number one way to preserve your string and make it last longer.

Following some simple weed whacking techniques will greatly increase the length of time your string will last.

Remember to always keep the string parallel to the ground, especially when tapping the spool to feed more string. This way the string is not hitting dirt or rocks, just nice soft grass.

Spool Size

Not all trimmer line spool sizes are the same, and this can really make a difference in how long the trimmer line will go without being replaced.

String Size

To make your string last longer you need to consider the size of your string, the style, brand, and string length.

Many string trimmer heads can hold different sizes of string, but most no more than .095. When choosing the string size, go for the manufacturer size for your model.

What Size String Does a Dewalt Weed Eater Use?

The Dewalt 20-volt, battery string trimmer uses dual 0.080-inch cutting lines on a 13-inch diameter head. It has a straight shaft and weighs 8.5 lbs. 

When threading a Dewalt weed eater, it is important you know the right string size. Using any other line with the trimmer can degrade performance and/or cause damage to the trimmer.

How to Remove the String on a Dewalt Weed Eater

To remove the string on a Dewalt weed eater you will first need to disassemble the head to be able to access it.

To take apart 20V weed eater head, follow these instructions:

  • Insert the rod through the hole in the string trimmer drive washer (small) and into the hole in the motor housing. 
  • Turn the spool housing clockwise. 
  • Remove the spool housing and the drive washer from the trimmer.

The string is wrapped on the spool. To remove, unwind the string in the opposite direction of the arrow on the bottom of the spool. Remove the end from the retaining hole.

How to String a Dewalt Weed Eater

Before installing the string or making any adjustments, it is advisable turning the tool off and disconnect the battery packs to avoid injury that can be caused by an accidental start-up.

To install more line on a Dewalt trimmer with a QuickLoad Spool Head:

  1. Cut a maximum 25 foot (8 m) length of trimmer line.
  2. Align spool housing eyelets with the arrow on the spool head.
  3. Thread one end of the trimmer line through an eyelet. Guide the line through to the second eyelet and continue to pull the line through until there are equal lengths of string on each side of the spool housing.
  4. Secure the spool cap from moving with one hand. Using your other hand, wind the string onto the spool by rotating the spool head counter clockwise. Continue winding until 5 inches (127 mm) of string remain on each side of the spool housing.

Some models, however, might come with the traditional head. The following are the instructions for loading the twine on a Dewalt weed eater with a dual-sided spool:

  1. Turn spool clockwise to unlock. The white nub inside the spool will rotate away from the spool window to indicate it is unlocked.
  2. Pull the spool straight out to remove.
  3. Remove any dirt and grass from the spool and housing.
  4. First, wind new line in the channel of the spool closest to the holding slots.
  5. Place the end of the cutting line into the retaining hole.
  6. Wind the cutting line onto the spool in the direction of the arrow on the bottom of the spool. Make sure to wind the line on neatly and in layers. Do not crisscross.
  7. When the wound cutting line reaches the beginning of the holding slots, cut the line approximately 4 inches (106 mm).
  8. Push the line in the holding slots on one side of the spool to hold the first line while you wind the second line.
  9. Repeat the above procedure for the second cutting line on the lower section of the spool.
  10. Once both lines are wrapped around the spool, place your thumb and finger on the holding slots to further secure the string and feed the end of each line through the two holes on either side of the head in the spool housing.
  11. Line up the white nubs inside the spool housing with the recesses of the spool. Align the holding slots with the two holes as close as possible.
  12. Push the spool into the spool housing and turn counter clockwise to lock the spool in place. Ensure the white nub appears in the spool window. Make sure the line does not unravel and wrap around the shaft below the spool.
  13. Pull both ends of the cutting line to release them from the holding slots. If the line extends past the cutting blade on the guard cut the line so it just reaches the blade.

How to Extend String on Dewalt Weed Eater

The Dewalt trimmer uses 2.032 mm diameter string. The Cutting line will wear faster and require more feeding if the cutting is done along sidewalks or other abrasive surfaces or heavier weeds are being cut. 

Check this too: Ryobi Weed Eater How to and Troubleshooting Guide

As you use the trimmer, the string will get shorter due to wear. To extend the string, gently bump the trimmer on the ground while running at normal speed and the line will feed. 

Note that extending the string beyond the 330 mm swath will negatively affect performance, runtime, and the life of the trimmer due to the potential of damaging the motor. Doing so may void the warranty

Oscar

In his spare time, Oscar loves tinkering with electronics. Solar panels, wiring, old TVs and sometimes DIY powerwalls. When he is not busy trying not to electrocute himself, you can find him in the garden tending to his vegetables and chickens.

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