How to Replace the Spring on a Black and Decker String Trimmer

The trimmer-head spring applies pressure to the spool. When the spool is tapped to the ground, the spring compresses, allowing the spool to contact the hub, which feeds line. The spring then pushes the spool back out. After years of use, the spring can lose some of its tension. This can cause the spool to not retract, causing line to continue feeding from the head.

Let's get started.

REMOVING THE SPRING   1. Remove the bump cap.

a. Depress the two locking tabs on the sides of the bump cap.

b. Remove the bump cap from the trimmer head.

  2. Remove the spool.

a. Pull the spool assembly away from the trimmer head.

  3. Remove the spring.

a. Remove the spring from the trimmer head.

INSTALLING THE NEW SPRING

  4. Install the spring.

a. Install the new spring onto the trimmer head.

b. Press/compress the spring firmly to seat it on the spindle.

REASSEMBLING THE UNIT

  5. Reinstall the spool.

a. Unwind approximately 6 inches of line from the spool. b. Secure the trimmer line in the lock-notch on the spool (to prevent the line from unraveling further).

c. Thread the trimmer line (from inside to outside) through the eyelet on the trimmer head assembly.

d. Install the spool assembly onto the trimmer head.

e. Pull the exposed trimmer line to disengage the line from the lock-notch on the spool.

  6. Reinstall the bump cap.

a. Position the bump cap over the spool.

b. Align the locking tabs on the bump cap with the slots on the hub.

c. Press firmly on the bump cap to engage the locking tabs.