Drum brake shoes, small one forward?

[Bradsp8]

Front brakes, stock D44 on a '75 Sport with drum brakes. Which do you guys put toward the front of the truck, the shoe with larger brake surface or smaller brake surface? Is the "primary" the larger or smaller? It seems it depends on who you ask and I wonder if there is a right/wrong answer.

 

[suthernboy]

My '76 Ford Truck Service Manual specifies (and illustrates) the shoe with the smaller brake lining surface as primary and positioned forward.

 

[Bradsp8]

Ok, good, that's what I thought. Thanks!

 

[Broncobowsher]

Small primary shoe toward front of vehicle.

When applying the brakes that one drags and puts extra force on the larger secondary shoe. The secondary shoe is stopped by the anchor pin at the top of the backing plate. The wheel cylinder is double ended so you have some braking in reverse, otherwise it could simply be a single piston (like trailer brakes that do allow you to back them while they are applied). The primary brake putting force on the secondary shoe is known as self energizing. The secondary shoe does more work since the primary is applying force to it. So the secondary shoe has more material so it will wear at the same rate. This applies for any drum brake system with a single anchor pin at the top, above the wheel cylinder. Some other stuff doesn't work the same, but generally anything from the 60's until disk brakes works this way. 50's and before, Toyota FJ40s, they are different.

So you are correct, small shoe toward the front.

 

[Bradsp8]

Thanks for the full explanation broncobowsher. Makes more sense now. The weird thing is that the pair of old shoes I'm taking off have the same size brake surface as each other where the new pair have one larger than the other. I checked the passenger side and it's the same way. At first I thought the PO had screwed up but wherever and whatever shoe he put on was certainly different that what I just purchased.

 

[bteutsch]

Short shoe to the front

 

[DirtDonk]

...At first I thought the PO had screwed up but wherever and whatever shoe he put on was certainly different that what I just purchased.

Did you make sure that all four were the same length too? I've seen people put the two short ones on the same side, and the two long ones on the other.
But I've also seen the wrong shoes come in boxes as well, so there's always that.
However, I've also known of some that purposely got the sets mixed up (sometimes by buying two sets) just because they figured they knew better and would re-engineer the wheel so to speak.

So you just never know about them pesky PO's anymore!

Paul

 

[Bradsp8]

Drum Brakes, small shoe forward? Hub concerns now....

Yes, both sides were the same. Both were set up with shoes consisting of the same size braking surface. All four of the old shoes appeared to be the same. Almost like they selected and installed four primary shoes when they last did a front brake job.

It sure is a lot of work pulling the hub apart then the drum off just to do a brake job. Crazy amount of work and about as greasy as I've ever been. Basically had to take everything apart so while in it knee deep I dove all the way in. I repacked bearings and put in new grease seals and new wheel cylinders and even replaced the soft brake lines. The old hoses were cracking on both sides and the wheel cylinder on passenger side was a mess and leaking everywhere. Gravity bled last night by myself and tonight with my assistant, wife or kid, I will try to bleed and adjust and test drive.

I'm worried about the hubs though, had a hell of a time gettting the selector back in correctly or what I think is correct. Then something clicked and reminded me to install it in the "locked" position and that worked. I say seemed to as I will have to test drive to see if the front wheels can be engaged. What is the best way to test this if I don't have mud or trails or gravel roads nearby? Can I lift all four tires off the ground and test 4WD engagement w/o a load?

 

[suthernboy]

Jack it up, lock the hubs, spin the tire, look and see if your axles are turning, if so, you're good.

 

[Bradsp8]

Suthern, thanks. I did lock hubs and when turn the wheel the axle turns so all looks good.

 

[DirtDonk]

I've done dozens of Bronco brake jobs over the years and not once have I ever separated a drum from a hub.
Never needed to. Just had the local shop put it up on the brake lathe as is and turn it as an assembly. And when I did need to change a drum, the hub-and-drum assemblies were readily available and not that expensive.

But then, things like prices do tend to change. I used to be able to buy a hub/drum for $40 to $45 bucks or so. And the drums were still USA stuff too!
I'm guessing it's not quite that easy any more?

Paul