working on our 54 ford victoria...installing brake shoes on the rear. The new shoes have linings that are different in length..one longer than the other. Anyone know wnhich is primary and secondary? primary faces front end. The linings on the original shoes are both the same length. Thanks...
Not sure what a '54 has but my guess is they are "self energizing" and the the front is the longer shoe. Posting some pic's will help. Welcome to the HAMB
All drum brakes are self energizing to a point, but the Bendix brakes Ford starting using in '49 for cars are Duo-Servo, and this design always has the shorter or primary shoe forward, just the oposite of the pre-'49 Lockheed non-servo design. Shop manuals show the brakes in detail, although sometimes the shoe length difference can be hard to see.
Cosmo's got it right. The short shoe is the primary, and it mounts forward. The secondary shoe has longer lining as it does most of the work, somewhere between 60 and 70%, the shop manuals say. They also say you should install the primary spring to the anchor first, and then the secondary. I've never heard the reason for that. Anybody know why?
There can sometimes be a clearance issue with the return springs and wheel cylinder. This "rule" changed throughout the years on some 9, 10 and 11" brakes, and whether they were auto adjusting or not. If the return springs are the same, it should not make any difference, but if they are different, it can. Generally, install the primary first and check the clearance to the cylinder.