I had the same problem and replaced the cable but that wasn't the problem. Check out this diagram: http://chevy.oldcarmanualproject.com/1929_54chevyparts/04/316.HTM. It turned out that the slot on my 5.150 (extension) was too deep so lever 5.149 would not move it when the brake was applied. I took the extension to a shop and they welded some metal into the slot to make the slot shallower so when the lever was moved (forward) the extension moved the front shoe onto the drum. I hope this makes sense.


It's a small world, but I wouldn't want to paint it.