Brake shoes for dummies

[fng]

Awsome post! I'm right here in this point of the game too. I'm dropping off my brake shoes for relining tomorrow, meanwhile I need a new inner seal to install.

[FrankyD]

The principle used with the M715 brake configuration is what they call "Duo-Servo", basically, that is why there is no lower shoe anchor. The ending result is that there is more pressure applied to the rear shoe ( when moving forward, of course) and is considered self-energizing. Shorter pad goes in front, more surface for the back shoe...

[brute4c]

The Quirks Manual, see Manuals link up top, says all the info needed for proper servicing:

GIVE ‘EM A BREAK
Brake shoes on your 5-quarter are different from what you’ll find on other tactical wheeled vehicles — the front, or primary, shoe in each wheel has a shorter lining than’s on the rear shoe. Make sure you install ‘em that way— and they’ll give you a brake.

And if you happen to have that brake shoe self-center anchor block off the backing plate, make sure you put it back with the arrow pointing toward the front of your 5-quarter. Otherwise, your brake shoes won’t fit against the drums like they’re supposed to — and you’ll get quite a surprise when you want to stop quick!

There is a drawing showing the arrow as well.

[robsgp]

Like you I was directed to the quirks (who'd have thought) manual when I asked, only mine was even more messed up. No two wheels were alike! I even had two shorts on one and two longs on another. When they came back from reline they were all the same.

[Jbush]

On M715 I had my drum turned and while adjusting the brakes I hear a grinding sound. Do I have to replace the shoes or what?

[67U20]

Like Dave says. Short to the front and long on the back. On the right side the star wheel is next to the secondary shoe (long shoe). On the left side the star wheel is towards the primary shoe (short shoe). Also make sure the arrow on the brake self-centering anchor block points to the front of the vehicle.

For those who have relined shoes, the linings are usually the same length so position doesn't matter.

When mine came back from relining, same length for all the shoes.

[jeepdan]

When mine came back from relining, same length for all the shoes.

I almost ended up with the same problem.

When the brake relining shop called me, to get payment before shipping them back.
I'm glad that I thought to ask, if they relined the short shoes to the original lenght.
They said, "did you want them left shorter? Nobody does that anymore"
Anyhow, they redid them with no complaints.
Mine also came back with the friction material bonded to the shoes instead of rivited, not sure if that is good or bad.

[Don Cavey]

The shoes that were on my truck when I got it were all the same length. Because some of the wheel cylinders had leaked, there were at least four shoes damaged. I got a rebuilt set from AB Linn and they had the short and long linings on the shoes. Those shoes went on the front brakes and the all-the-same-length shoes went on the rear. I didn't know that it was a common thing with our brakes...

[67U20]

...Mine also came back with the friction material bonded to the shoes instead of rivited, not sure if that is good or bad.

Bonded linings have been around for quite awhile. In one respect they are better than rivets. Rivets, generally speaking, function on a shear plane. So the actual strength is localized to the rivet shank, where bonding has the entire shoe to lining area in a shear plane. Plus rivets can work loose and I've yet to see any real de-bonding of bonded shoe/lining.