The picture below shows an exploded view of Austin-Healey 100 rear brakes. This image is from the Moss Motors website. The same drawing is in my 3000 shop manual. The pertinent info is in both drawings: Direction of Forward Rotation on both drawings is indicated. The fact that the direction of rotation is indicated leads me to believe its important.
when I pulled my rear brake drums, both sides had broken front return springs, and BOTH SIDES HAD THE BRAKE CYLINDER (# 15)AT THE FRONT which is opposite to the depictions.
It would appear whoever rebuilt these brakes prior to my ownership put the backing plates on upside down. It looks like I can take the bolts out of the backing plate and rotate them 180 degrees, which means I will have to reroute the brake lines to the rear of the axle..
my question is, does anyone know if and why the cylinder should be on the rear of the backing plate to operate properly? Could the improper setup be why the two return springs were both broken at the same spot, between the lower hook and the spiral?
Shouldn’t make any difference where the cylinder in. On a Land Rover I’m restoring,it seems to be standard practice to rotate the front back plate by one set of bolt holes, making the adjusters more accessible. Is it possible that the springs were broken during the forced drum removal ?
I could see part of one of the springs laying at the bottom of the drum as soon as a gap opened up between drum and backing plate, so I believe they had broken at some time in the past. Being the spring at the cylinder end of the shoes, they were probably not retracted when the car was put on my lift, TWENTY years ago! That gave the brake linings plenty of time to adhere to the drums!
Here’s another question for you. My brakes are basically a reverse of the sketch above, with the operating cylinder now at the “front”. Should the empty (unlined) portion of the shoes move to the front also? I believe the were not when I disassembled them, maybe the were grabbing because the fully lined part of the shoe hit the drum first?
I agree. Basically I’m setting things up as if the shoes, wheel cylinder, and adjuster setup are just rotated 180 degrees on the parts sketch above. Put the first side together today with new cylinder, spring, Everything went together fine. Will take pics tomorrow.