Husqvarna 50 Workshop Manual page 9

Assemble the brake band and knee link. Insert the roll
pin into the brake band so the open side of the pin is up
as shown in photo.
Insert the linkage and band assembly into the cover.
Secure the knee link to the cover with the retaining pin.
Slide the brake spring over the linkage spring post.
Using a flat bladed screwdriver, depress the spring, then
carefully press the spring end into the cover.
Install the cover plate.