Small Engine Troubleshooting Problems? Ask a Mechanic Now.
Welcome to JUST ANSWER small engines, let me try to help you !! I don't know it all, but maybe together we can get you a satisfactory answer!
# 3 in the above link are the brakes for the spindle pulleys, each one should move and contact the pulley when deck is shut off. You need to free up the stuck parts! This only affects the blade brake, and has nothing to do with the transmission brake for the tractor.
I see question is still open, did you see my links and find what you needed?