Brake shoe thicker lining
After having rear brake cylinders, shoes and pipework fitted to my 2001 Ford Focus, one side has developed a squeal on braking. Rather than take it back and lose it for a day, I removed the drum with the intention of chamfering off the new shoes and making sure there was no wear ridge left on the drum. Then I noticed that one shoe lining was thicker than the other – the garage I used says this is how they come and that the thicker one goes on the leading shoe. However, the Haynes manual makes no mention of this and, if you were renewing them yourself, the old ones would be too worn down to be able to tell. Can you tell me if this is true and, if so, how you'd know? M Hopkins The garage is perfectly correct. The new brake shoes have a thicker brake lining on the leading shoe. As the majority of braking action is done by the leading shoe, it is this shoe which wears more quickly. The reason for this is that the shoe which throws out against the direction of rotation will be dragged into the drum by the rotational force, causing higher friction, whereas the shoe on the trailing side will be pushed back. Old brake shoes will normally be slightly unbalanced in terms of friction material, but less so as the wear will balance out by the end of the brake shoe’s life.
A new set of brake shoes showing the variance in size between the leading and trailing shoe.