Brakes: Leading and Trailing Brake Shoes.

[Aussie Hawk]

I'm overhauling the rear brakes on my wife's VW van (I know a non-Stude question, sorry ;-). When I went to fit the new brake shoes I noted they were all long linings, I immeadiately thought they had supplied me four trailing shoes instead of two leading and two trailing. On futher examination of the old shoes I was replacing they were all the same length as well, even though the manual shows the normal shorter lining on the leading shoe and longer lining on the trailing shoe.
I called the supplier on Monday who said, 'yes that was right they are all the same length now, that's the way they come'. I also spoke to a local Stude parts supplier who said when he gets Stude brake shoes relined they come back all the same length. Which prompts me to ask the following questions;

1. Will it cause a problem if the leading and trailing shoe linings are the same length ? (The VW brakes with the old shoes at the same length lining worked fine, they are being changed because of being soaked with brake fluid due to a leaking cylinder)

2. If they work being the same length, why were they different lengths on the older shoes ?

[Studebakercenteroforegon]

Secondary brake shoe linings can be one of three things - longer, thicker, or harder.

[Aussie Hawk]

Secondary brake shoe linings can be one of three things - longer, thicker, or harder.

OK, but what about the Leading, (Primary) shoe, can it be the same length as the secondary ?

[StudeRich]

It seems that one of the few reliners that use the correct long & short linings is the one the Studebaker Wholesaler uses.
So at least some of the Studebaker Vendors have the right stuff, I check every set I get to be sure there are 2 and 2 of each in the box.

The Bendix style Wagner Brake system we have on most of our Studes. was designed to have the forward shoe "Apply" the braking action forcing the rear shoe to take most of the load.

I have installed same length linings on Disc Brake Rear Drum Studes. with no problem, but those brakes are a totally different design, designed not to self actuate and stop too hard on purpose.

[Aussie Hawk]

It seems that one of the few reliners that use the correct long & short linings is the one the Studebaker Wholesaler uses.
So at least some of the Studebaker Vendors have the right stuff, I check every set I get to be sure there are 2 and 2 of each in the box.

The Bendix style Wagner Brake system we have on most of our Studes. was designed to have the forward shoe "Apply" the braking action forcing the rear shoe to take most of the load.

I have installed same length linings on Disc Brake Rear Drum Studes. with no problem, but those brakes are a totally different design, designed not to self actuate and stop too hard on purpose.

Maybe that's the same idea on the VW Van, as it has disc brakes on the front/

[StudeRich]

Matt, that depends on if it has a Proportioning Valve or not, the reason Studebaker did that is they had no Valve to equalize the force.

[Bud]

The VW's I've worked on have had equal length brake linings. VW's don't use a self energizing brake system so the shoe length isn't critical, there isn't really a leading or trailing shoe. Bud

[Aussie Hawk]

The VW's I've worked on have had equal length brake linings. VW's don't use a self energizing brake system so the shoe length isn't critical, there isn't really a leading or trailing shoe. Bud

ts

Thanks Bud. What confused me was that the pic in the manual showed the shoe linings different lengh ?? Anyway, I'm putting the brakes together today after flushing the lines. How's this for a coincidense - I live in Hawthorne, Brisbane.

[RadioRoy]

I think that modern brake shoe reliners make them the same length for two reasons:

1. It's easier for them to make them all the same

2. Many back yard mechanics won't notice the difference and, if they are the same, then they cannot be installed reversed by mistake.

I think the shoes were originally different lengths to normalize the wear, so that both shoes wore out at the same time.

[Bud]

Back in the old days and if my memory serves me correctly, the primary and secondary shoes were lined with different composition friction material. I believe that is why the linings were originally different lengths. Bud

[DEEPNHOCK]

In order for a self energizing drum brake setup to work, you have to have a floating lower pivot.
The pressure applied to the wheel cylinder pushes the shoes outward.
Since there is less surface area on the leading shoe, there is a higher psi loading on it.
This pushes the floating link connection at the bottom and applies more force to the rear shoe.

If you had a fixed lower end, then it would not matter about shoe length.

Since the braking effort, front wheel to rear wheel, makes the rear brakes do less of the work load, then a brake supplier might skimp and make all the lining the same length on the rear.
Cost control more than anything.

T'were it me, I'd be trying to replace what the brake manufacturer designed, or put something better than OE on there.
HTIH
Jeff