I had to specially order some front brake shoes the other day and I was wondering why there are two different sizes for the 68 F100? They asked me if it was 11x2" or 11x3". And they weren't even sure as to why the difference. I was too lazy to take the drum off to see what size it was before I ordered them so I just took a lucky guess and ordered. My luck, it won't be the right size, oh well.

 

no clue. maybe those are the different sizes for front or back?
but i do know one shoe will have more pad on it than the other one. on the front of the truck the big shoes go in the front and on the back of the truck the little shoes go in the front. because of the way the brakes engage their is a leading shoe and a trailing shoe. this gives you the best stopping power and shoe life.

 

Correction to what Danger_Dave said.

The short shoe will ALWAYS go to the front.

 

why? the reason the short shoe goes on the front on the back wheels is because when you go in reverse down a hill or reverse period that becomes your front of the vehicle and your 70% stopping power. the shoes remain stationary and only pivot at the bottom, the top is where they separate and the force is applied from the wheel cylinder. why does the front shoe always wear out the fastest? because it is the leading shoe and is where all the force goes. it bites, while the trailing shoe drags, why would you want to put the small shoe in the front on the front of the vehicle? why do they make one shoe smaller than the other? for this reason. on the front of the vehicle alot more force will be exerted on the leading shoe than the trailing shoe, it is the bread and butter of your stopping power.

 

You put the primary (short) shoe forward to help with the self-energizing action of the brakes. Having less lining there allows the edge to bite in and push down, pushing the secondary shoe into the drum harder, assisting the brake pedal effort.
Check out this page:
http://www.tpub.com/content/construc.../14273_257.htm
Having the primary shoe to the rear will cause reduced brake effectiveness. I don't know your driving habits, but I don't have much need to stop quickly in reverse, even if I did there is still the matter of the proportioning valve reducing pressure to the rear brakes. When you are loaded down, you will want the rear brakes to slow you properly.

 

sorry but i still dont understand and that link didnt really explain much about where to put the larger shoe and why

 

Well, don't blame me when you rear-end someone because your brakes didn't work right.
They say to do it that way for a reason, I saw a reason in that, but you didn't so do it your own way.
BTW, in that accident, you will be found 100% at fault for having incorrectly installed your brakes.

 

Danger_Dave, I've done brake jobs for the last 45 years.

You do it your way, and I'll do it mine.

Not something worth arguing about, until you have to stop suddenly.

Then there will only be one of us around to discuss it...

 

i have been running mine this way for the last 6 months and theyve never felt better, and i've had to stop suddenly several times here in jersey because of the way people drive. i dont mean to argue, but the tons of research i have done on the internet is 50/50 on whats right and whats wrong. my uncle has been doing brakes for 30 years, and my friend who owns his own shop about 20 years, and me, well i'm just a do it yourselfer, but i have seen my fair share of people who do things for a living or have been doing them for a number of years yet they still do them the wrong way. if you are so sure i would like to know exactly WHY that way i can stop rambling and maybe even switch my shoes back around, but i've yet to find a good enough reason when they work so much better this way and with the way drum brakes work.

 

Drum brakes with a floating adjuster (like the ones on our trucks) are "self-energizing."

When the vehicle is going forward and you apply the brakes, the wheel cylinder pushes both shoes out to contact the drum. When the front shoe contacts the drum, it tends to rotate with the drum. The rotational force is transferred through the adjuster link to the rear shoe. So now the rear shoe is being forced against the drum by the wheel cylinder and the front shoe. On properly-adjusted brakes, the rear shoe will have a tendency to be "pushed" against the anchor because of this rotational force.

Because the rear shoe is doing more "work", it needs to be longer because it is doing a larger percent of the stopping. It also evens out the wear, as the rear shoe would wear out quicker if it were the same size since it is doing more braking than the front shoe.

Moving in reverse, the exact opposite happens. As the rear (secondary) shoe is "pulled" by the rotation of the drum, it also pulls the cable or link in the self-adjusting mechanism, activating the self-adjuster lever, thereby activating the lever against the star wheel on the adjuster. If this travel is great enough, the lever will move far enough to engage in the star wheel, and when the brakes are released, the star wheel will be moved.

Satisfied?

 

Ditto to what 70_Ranger XLT said. The smaller shoe ALWAYS goes in the front. If you guys would just swap to disc brakes you wouldn;t have to argue about it so much!

 

70_RangerXLT, jhooch, Ford_Six are all correct. I was an ASE brake tech many years ago and the primary shoe ALWAYS went in front regardless of front or rear brakes.

 

If the brake shoes are reversed...does that mean that the brakes will not adjust correctly?? What other dangers are possible??

 

They will adjust just fine.

The shoes are identical, primary or secondary.

Issues you will encounter are reduced braking force and excessive wear. With the way they are designed, having the majority of the braking done by the secondary shoe, if they are reversed the "short" shoe will wear more quickly.

 

well thanks for the explanation, thats interesting stuff. i'll give it a shot and switch them around and see how they feel.