Extra part while reassembling my portafilter.

Katheryn, that is the handle return spring... It fits between the portafilter housing and the plastic valve assembly. To get to it, separate the plastic portafilter handle by removing the three phillips head screws and their bushings. Carefully remove the heavy portafilter housing, and be sure to not lose the coiled valve spring. Next, remove the coiled valve spring and set it aside. Then hinge open the outlet valve pin so that you can see the center four pronged center hub of the plastic portafilter valve assemble. WIth a butter knife, carefully wedge up the plastic assembly until it clears the four retention prongs. Flip over the assembly, and you will see two distinct pin bumps that are integrated into the plastic assembly. The looped end of the c-shaped ring goes over the larger of the two pins. Place the looped end over the pin and press it against the plastic assembly body. Hold the wire fast to the assembly and then bend the wire around so that the bend around the other end is held tight against the other pin. I have enclosed a picture for your reference. When putting the assembly back together, insure that the larger of the two pins is placed into the round corresponding portafilter housing recess as you press the plastic assembly back onto the portafilter housing. Let me know how it goes. Leo