Ok these rear brake will not go willingly...
Some time after the auto-adjusters in the rear drums tightened themselves up, I started noticing the rear brakes (mainly the left one) being very grabby again both when applying the footbrake and when pulling on the handbrake, so I know its definitely the rear brakes.
So much so that I'm having to modulate the brake pedal very delicately when pulling to a stop to avoid an abrupt, over dramatic stop as though I'd slammed the brakes on.
So I'm trying to figure out why it has come back and what is causing it. All of the leading and trailing shoe edges have been carefully chamfered, everything is cleaned and lubricated, the only thing I can think of that might be causing it to grab is that the shoes may still be snagging slightly on a groove on the ears on the backing plate.
People may recall I mentioned the whole backing plate seems to have a hard black coating of enamel paint (?) or something similar, including the raised ears, and some of the ears - mainly the ones near the top (cylinder) side that move the most have a grove worn right through this "paint" to the metal, creating a groove that the edge of shoe may snag on. Here is one example:
I put plenty of copper grease on the ears and it seemed to help a lot but I can only assume the shoes are still snagging slightly on these grooves in the paint, thus allowing the shoes to get stuck so the leading shoe is sometimes doing all the work, thus grabbing. The grabbing isn't always there so it makes me wonder if when the shoes move over a bit to be more centralised it stops grabbing.
So my question is - should I be wire brushing all the paint off the raised ears back to bare metal and then applying a new layer of copper grease so that there are no lumps/groves for the shoes to catch on ? Are the shoes temporarily being biased towards the leading shoe instead of equalising all that it would take to cause the brakes to become grabby and oversensitive at low speeds ?
I can't think what else it could be as everything else is clean and well lubricated and the shoes are in perfect condition, no problems with the cylinder, self adjuster etc...