Your photo shows a yellow spring and the related hardware that retains the actuator and the shoe to the backing plate. The back side of the retainer has a sleeve that goes through the actuator and the brake shoe. It may be possible that the hole in the shoe is too small or it has some sort of coating on it and could be binding and causing the tang to not set on the star wheel. My reference materials show a straight spring on some and others a beehive type design. The book I have calls it a return spring. I don't think it matters much except both are considerably smaller and weaker springs that would apply less pressure. My suggestion would be to do a test and remove the return spring and see where the actuator sets relative to the star.
Fred

Something I learned during my 50 years of working on this stuff. Don't throw anything away until you are finished and it works.

Last edited by rfs56trk; 12/31/2019 10:50 PM.

1956 3100 Pickup/Red/350/3sp OD/PS/Disc Brakes
1957 Bel Air Sport Coupe/Red/355/TH350/PS/Disc Brakes
2017 Silverado LT Single Cab SB/Black/5.3/6 Speed Trans
1947 Willys CJ2A w/F-Head engine