Jaffa, what's the engine model number?
As mark's diagram shows, the wide end of the brake spring should bear directly against the retainer [aka dog plate].
Plastic/nylon washers belong in two places. That is, between the retainer plate and pulley, and sometimes between the pulley and housing as well.
Definitely not against either end of the brake spring. That should have metal against both ends.
As its name implies, that's there to provide drag on the retainer, so that it spins slower than the pulley, when the cord is pulled. The lugs on the retainer will then push the pawls/dogs outwards, if the retainer is correctly installed.
