How Do You Advance A Trimmer Line?


The trimmer line is the part of the trimmer that does the main work of cutting grass and weeds. After winding it into the spool, you must properly advance it so that it can do its job. So how do you effortlessly advance your trimmer line and use it for cleaning up your yard? 

How you advance your trimmer line depends on what feed mechanism your trimmer has: 

  • If it has a bump-feed mechanism, you can advance the line by gently bumping the trimmer head on the ground. 
  • If it has an automatic feed system, you don’t really have to do anything because the trimmer will dispense more line whenever it gets too short.
  • If it has a fixed-line trimmer head, it uses pre-cut lines that must be reloaded manually after the old one runs out.

If you are struggling to advance your trimmer line, or want to know more about it, keep reading. I’ve covered all the details about advancing trimmer lines and winding in a new line after the previous one wears out. 

Advancing Trimmer Lines for Different Trimmers

Trimmer lines are wound into the spool within the trimmer head. You must constantly advance it from the spool into the cutting head to use it for trimming your yard. 

Trimmer lines are advanced in three different ways, which are described down below: 

1) Bumping the Trimmer Head 

The bump feed trimmer heads must be bumped or tapped on the ground to advance the line. They make use of a spring mechanism that uses a centrifugal system to feed out the line each time the head is bumped. 

Once the line is advanced, a blade on the trimmer head’s safeguard cuts it to an appropriate length and prevents it from being too long. A cutting line that is too long can get stuck in fences and flowerbeds, wearing it down quickly. 

The bump feed system is a straightforward method of advancing the line. It gives you complete control of your line and allows you to use it more efficiently. 

However, you must be cautious while bumping the trimmer head as you may damage the spool or spring if you tap it too hard. 

2) Automatically Advancing Line 

The automatic feed trimmer head uses a sensor to detect the line length in the cutting head. Once it falls below a certain level, it automatically advances the line into the cutting head. 

The trimmer head also has a blade for cutting extra dispensed wire and reducing it to an appropriate size.

An automatically advancing line offers several advantages. You can focus on getting a perfect trim instead of constantly worrying about bumping new line. It also speeds up the process, and you don’t need to take frequent pauses to advance the line.

However, trimmer heads with automatic feeding are generally more expensive, and they tend to use more line over the same period of time compared to their bump-feed siblings. 

3) Fixed Line Feeding

Pre-cut lines are threaded into the fixed-line feed trimmer heads. 

Instead of winding a line into the spool, you can put pre-cut lines that are easy to load. 

The pre-cut lines feed out and cut wild weeds and long grass until they wear down. Then, they must be replaced with new pre-cut lines.

You can use thicker diameter, resilient trimmer strings with a fixed line feed. You must turn off the trimmer each time the line runs out, and put a new one in. It can make yard cleanup more time-consuming.

Putting Fresh Line Into String Trimmers [Three Methods]

The trimmer head won’t feed out the line if the spool is empty. So, each time the line in the spool runs out, you must wind in a new line! 

Putting a fresh line into a trimmer head is different depending on which feed system your trimmer uses. Let’s look at how each of them works: 

1) Putting New Line in a Bump Feed Trimmer Head 

Before beginning the winding process, purchase a durable, high-quality, thick line that is compatible with your trimmer.

Below are the steps for putting a new line into a bump feed trimmer head: 

  1. Unscrew the bump knob and remove the spring to open the trimmer head. 
  2. Pull out any leftover line and throw it out. The old line becomes brittle and breaks easily. So, get rid of your line if it’s been in the trimmer for some time.
  3. Take a 20” line and fold it in half. The center point of the halved line (which forms a small loop) will be your beginning point. Insert it into one of the two holes on the top surface of the inner reel. Pull it through the hole until only a few inches remain. 
  4. Loop the short ends into the other hole of the reel. Then, pull the longer ends and close the loop. 
  5. Wind the line around the reel in the right direction. The reel will often have an arrow showing the path. Stop spooling the line when only a couple of inches are left. 
  6. Insert the two parts of the doubled line into separate holding slots. 
  7. Put the spring back in its place.
  8. The spool head will have two eyelets. Locate them and feed one line through each of them. 
  9. Place the reel into the spool head. Make sure to align the holding slots and the eyelets. 
  10.  Push the reel down to compress the string and put the bump knob back in its place. 
  11.  Screw the bump knob onto the top of the trimmer head to reassemble it. 
  12.  Finally, gently pull both lines, and you can then begin trimming your yard. 

Remember to tap the head against the ground to advance the line and effortlessly complete your tasks. 

2) Putting New Line in an Automatic Feed Trimmer Head

Automatic feed trimmer heads often require pre-wound spools

Since they are already wound, you don’t need to do much. Here are the steps for putting a pre-wound spool into a trimmer head: 

  1. Open the head of the trimmer. 
  2. Remove the tape holding the new line in place on the spool and unwind a few inches of it. 
  3. Insert the unwinded line into the eyelet of the head. 
  4. Place the spool on the shaft of the trimmer head and push it down. 
  5. Then, put the cap back onto the head and snap it into its appropriate place. 

Your automatic feed head will automatically feed the trimmer line as the previous part of it wears down. 

3) Putting New Line in a Fixed Line Trimmer Head

Fixed-line trimmer heads use pre-cut lines. Simply fold the line into half and insert its two ends into the eyelet of the trimmer head to load the line! 

You must repeat the process each time the old line wears out, and you need to replace it with a new one. 

Peter Toth

Hi! I'm Peter, the owner of BackyardGadget. Working around the house has always been a big part of my life. I've created this site to share my experience, and to help people choose the right tools for the job. Thank you for stopping by!

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