Squeaky Brakes on 47

[Old Henry]

My front breaks have been squeaking more and more over the last few week. I thought maybe the shoes were worn out and the rivets were rubbing on the drums so took a peek and this is what I found.

Shoes still with a lot of wear left on them and no rivets showing through.



Brake drum smooth as glass.



The squeaking started with the left wheel (which these picture are of) with a little grabbing but now both front wheel brakes are squeaking about the same. Only squeaks when brakes applied.

Why and what to do about it?