Symptoms
- Bumping the head does nothing
- Line breaks off short and doesn't come back out
- Line is tangled or welded together inside the head
- Head rattles but no new line appears
Likely causes
- CommonLine tangled or crossed on the spoolImproper winding causes the line to bind against itself inside the spool.
- CommonLine fused from heatFriction heat can melt nylon line together into a clump.
- PossibleDirt or grass packed in the bump headDebris jams the spring-loaded bump mechanism.
- PossibleWorn or broken eyeletsCracked eyelets snag the line as it tries to feed out.
- Less commonLine too thick for the headUsing oversized line for the trimmer model prevents proper feeding.
What to do
- Shut off the trimmer and let it cool before touching the head.
- Remove the spool and check for tangled, crossed, or melted line and remove any clumps.
- Clean out grass and dirt packed around the spring and eyelets.
- Rewind fresh line following the arrows molded into the spool, keeping wraps tight and in the correct direction.
- Feed the line ends through the eyelets before reinstalling the spool cover.
- Confirm the spring moves freely and the cover locks in place with an audible click.
- Test by bumping the head on the ground while the trimmer runs at full throttle.
Tools and parts
- Replacement trimmer line (correct diameter)
- Small screwdriver
Trimmer line spoolSearch: “trimmer line replacement spool”
Trimmer head eyeletsSearch: “trimmer head eyelet replacement”
When to call a pro
If the bump mechanism itself is broken or cracked, replace the whole trimmer head rather than repairing it.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.