19 replies to this topic

[surfblue]

I've found with a lot of modern shoes that the heels are too long or badly shaped - where the heel of the shoe sits in the wheel cylinder and the brake adjusters is subtly the wrong shape.

 

If you offer the shoes up to the drum they are probaby the correct diameter and round enough to work.  When they are sat on the hub they can effectively become an oval by being pressed out too far.
*If* you can wind the adjusters in far enough to get the drum on (not guaranteed) the the contact patch is tiny.
2 minutes with a file to dress them back to a more acceptable shape and you'll be fine.

 

First time I did this after working out the problem was a revelation.  Went from failing on brake efficiency to a handbrake-turn monster in half an hour.  Not had rear brakes so good since the late 90s...

My hand brake is really inefficient at the minute despite adjustment, I wonder if this is the issue. Can you stick on a picture to show where you file material off?

Thanks.

[Mrt88]

Hi all,
Thank you so much all the advice. I'm going to try and get these all back on tomorrow. I'll try everything you've all mentioned an give you all some feedback.
Thanks all!
Theo

[dklawson]

Consider the two pictures below (not mine... just found on the web), both showing a left, rear brake backplate assembly.  Look at the shoe friction material.  The friction material does not completely cover the metal shoe but is "cut back" an inch or so from one end.  The end that is relieved is the end that would touch the drum first when you think about what direction the drum is rotating.  Therefore... the right side would be the mirror image of the pictures below.  As Viper said, a number of the brake shoes available now have the friction material extending too far to the end of the metal backing.  If you file it down a bit (don't have to completely remove all of it) then the shoes contact more like they are supposed to and give a firmer pedal.

 

 

[Vipernoir]

Even with the extended lining shoes they are still the same diameter as the inside of the drum - i.e they are concentric circles.

The problem is that metal at points A, B, C & D is the wrong shape and instead of the shoes forming a circle when installed they form an oval - think of a US oval race track, the corner are the same at each end and would form a circle if the straights were removed.
If you carefully file off a bit at points A,B,C & D you can return the oval to a circle.

Attached Files

•  null-39.jpg   70.05K   23 downloads

[andyapanel]

I agree with Vipernoir. I had exactly the same trouble a few years back with replacement shoes from a reputable supplier. I eventually put the new ones on top of the old ones to check they were identical. There was way too much steel at the top and bottom contacts. I just ground them back to the correct size and everything was fine.

I hope you get back on the road soon.

 

by the way I always chamfer the edges a little.

Edited by andyapanel, 27 April 2014 - 11:57 AM.