Another brake question

[Keith Seymore]

One other thing to consider, since this sounds like a recent rebuild:

The rear shoes are "ground" such that the contact patch starts in the center (both side-to-side and lengthwise) and then increases as the shoes are seated.

If the contact starts at the ends then you will get a chatter and noise; starting the wear in the center keeps them quiet while they are breaking in.

Perhaps it is too recent and they are not fully seated yet.

K