I'm sorry guys, I know there have been a few recent and many old threads about drum brakes. I have read all I could find, but still have a question about primary and secondary shoes. Which has the longer lining, the primary or the secondary ( I think there is often conflicting thoughts on terminology as to which is which) , and which goes towards the front of the truck (longer or shorter linings)? My 48 F1 is now stock front brakes, and the rear has a 70 F150 9" with self adjusters and E brakes. I was finally healthy enough to work on it but when I popped the drums well parts fell out, so I'm screwed up somewhere. Which is very typical for Me,but It feels good to get my hands dirty again.

 

If memory serves! Forget it. My memory left with my good looks! Follow the pics below and Doug's advice




Something like this.

 

The shorter shoe is the primary and the longer shoe is the secondary. The primary shoe goes on the front and the secondary shoe is on the rear. If you look at the picture above , you will see what I am saying. This is true for both front and rear axles.

 

Post deleted

 

In that diagram Denny the forward shoe shows the shorter one, the arrow points that way..

 

You are absolutely right! Geez, maybe I should try to find some of those old cars and tell the current owners I screwed up! I was taugt how to rebuild brakes, way back in 66 when I worked an an apprentice mechanic one summer. I have been doing it that way ever since. Still have the very snap-on brake tools they pushed me in to buying.
My apologies to Jim and Cougar. I will, if I can, delete my P poor posts.

 

Thanks' guys. After reading many threads spanning over a decade, it became apparent that there was some confusion over this issue. There was definitely confusion on my end. I just ordered a new drum to replace the new drum I sacrificed in the name of learning the hard way. "ANY HOO" I always appreciate the quick help that I always get rite here on FTE. Rockin on slow but sure, have a great weekend everyone.

 

Just don't do what I have been doing for years. Assume the pictures are of the drivers side!

 

in the image above, this prospective has to be from the passenger side view. Note the orientation arrows.
if you look from the rear of the picture, then you'd have the driver's side view.

it is all in the arrows.

 

I have always just remembered 'Long shoe last'. As in toward the rear. Don't know where I heard that many years ago but it stuck.

 

Correct. This is because, when stopping with the truck moving forward, the primary shoe is self-energizing while the trailing shoe is self-disengaging. Since both have the stationary pivot at the bottom, the primary shoe leading edge contacts the drum first while the trailing shoe trailing edge makes initial contact. Thus the braking action on the primary shoe tends to pull it tighter into engagement, while the trailing shoe does the opposite. The trailing shoe has more braking surface to try to equalize the braking effort on both shoes. This is true for all single dual piston wheel cylinder designs.