Angle of Brake Arms

RawhideKid

RawhideKid

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After reading waaaaay too many postings on brake adjustment, and the Service Bulletin Nov 1928 pg. 298, 299, 300, I am a bit confused.

From all the postings and advice I have determined that the Front arms need to be set at a 15° angle, but I am not sure what the rear brake arm angle is to be before adjusting the rods to length. According to the Service Bulletin, it says nothing about a starting angle of the arms before starting the brake rod adjustment.

While I am at it, what about the E-brake arms?

Thanks.
 
On the rear brakes and e-brake you just take up the slack and then adjust the clevis yoke so the pin just slips into place...it's tough to tell when the slack is taken up if the anti-rattlers are in place.....I set mine initially with the drums off so I could see when the shoes and band started to move...

At least that is what I have read.
 
I am close to diving in on my brake adjustments as well. I got them set so they work pretty good, getting a few miles on them first. I easily have 15 degrees on the fronts, I adjusted up the back rods until they just started to pull hard. I'm waiting for a day that I can spend going through the procedure.
 
OK, FWIW.
I have read and read and since I am not into working with wood, this is how I think I will approach this.

First, get all the brakes installed and the service brake arms set at 15°, front and back and the cross bar set so it can NOT return to hit the cross member with the pedal returned to top position, since the rod from pedal to cross bar is adjustable too.

Now, since Randy Gross doesn't install brakes, he has no thoughts on hos to adjust them. So, I will bring the adjusters up until the brakes lock the wheel from turning, then back off 2 clicks or until the wheel rolls free, no more than 3 clicks.

I really think this should work since I do NOT want the rear to lock up before the fronts, but have equal braking on all wheels.

If I find, after driving and braking, from easy to hard, that one wheel works harder or heats up, readjust to get all wheels doing the same work.

But as a starting point, just lock up, and back off to turn freely.
 
RawhideKid said:
After reading waaaaay too many postings on brake adjustment, and the Service Bulletin Nov 1928 pg. 298, 299, 300, I am a bit confused.

From all the postings and advice I have determined that the Front arms need to be set at a 15° angle, but I am not sure what the rear brake arm angle is to be before adjusting the rods to length. According to the Service Bulletin, it says nothing about a starting angle of the arms before starting the brake rod adjustment.

While I am at it, what about the E-brake arms?

Thanks.
Click to expand...

I see a fatal flaw in your post and I hope it is just because you wanted to be concise. The 15° angle is the angle you are left with when all the slack removed in the assembly. You pull the lever by hand as if the brakes are going to be applied and when you start to move the shoe the angle should be 15°.
 
"I see a fatal flaw in your post and I hope it is just because you wanted to be concise. The 15° angle is the angle you are left with when all the slack removed in the assembly. You pull the lever by hand as if the brakes are going to be applied and when you start to move the shoe the angle should be 15°."

Ok, so you are saying that when I have the cross shaft and rod correct, I should wind up with a 15° angle at the beginning of the brake shoe movement?

This sounds possibly wrong. Not to argue.

The way I read the Service Bulletins and forum postings, the angle should be the relaxed setting on the wheel brake to "start the braking process". With this it gives the cross shaft 15° travel and pedal enough travel to lock up all the brakes without bottoming out or running out of pedal.

Now, I could be wrong, but this is how I read it.
 
When you get the front brakes apart i think you will see that Mike is correct.

With the original operating wedge and operating pin the cam on the actuating arm will not even begin to move the operating pin until the lever is near 15° or even vertical...

The "pills" that fit into the wedge help you set this angle by effectively adding length to the operating pin
 

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Mike is absolutely correct. The wedge must be actually operating the shoes, all slack out, when the arm is still tipped forward 15*. The solution is to lengthen the operating pin.

I really don't like the pills. They are too coarse of an adjustment. "1 is not enough, 2 is too much" sort of thing. Also, they put the pin end up pretty high in the wedge hole. I'd hate for that pin to somehow jump out! It is better to weld up the end of the pins to get the desired angle of the arm. Weld up and then grind down to a nice round ball ends. Then the pin sits deep in the hole on top of the wedge, as Henry designed it.

YMMV.

:D
 
Jim/TX/GA said:
Mike is absolutely correct. The wedge must be actually operating the shoes, all slack out, when the arm is still tipped forward 15°. The solution is to lengthen the operating pin.

I really don't like the pills. They are too coarse of an adjustment. "1 is not enough, 2 is too much" sort of thing.
:D
Click to expand...

I agree, the brake shims (pills) from the vendors are pretty thick. I got some shims from a club member that are ~1/2 the thickness of the ones from the vendors. In Flathead Ted's video he shows how to 'make' your own shims so you should be able to make them any thickness you want (within reason... :rolleyes:)

Make sure your operating pins are not worn also. I just installed new ones from Bratton's and was able to use just one thin shim.

Mike is right, on the front with all free play out the angle should be ~15° toward the front of the car.
 
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I needed 2 pills on one of my brakes. Did not want to put 2 pills on the bottom for the reason expressed in post #8. I put one on the bottom of the pin and one on the top of the pin. Seemed to work for me. I don't know what some of you experts think of this but I am willing to learn. Maybe this was a bad idea.
 
SeaSlugs said:
its not only the push rods that are worn but both the pockets they sit in as well. that pin acts like an air hammer as you drive and engine vibrations especially on worn out brake systems that dont keep pressure on the rods/arms.
Click to expand...

Haha, I can relate to that! :p:p But if all the free play is adjusted out and everything lubed up nicely, there shouldn't be too much Jack Hammerin' going on. ;)
 
Seems to me the critical angle is not the 15* but the angle when the brake is on real hard. It should be 90* to the brake rod there by giving maximum leverage. JMO.
 
wmws said:
Seems to me the critical angle is not the 15* but the angle when the brake is on real hard. It should be 90* to the brake rod there by giving maximum leverage. JMO.
Click to expand...





Thats correct. Beyond 90/0º leverage is lost. The 15º spec is good to keep the arm within the 'leverage' range.
 
This brake system is non-energizing. The rear brakes should lock just before the fronts.

The service bulletins says how they should be adjusted. I'm a fan of a brake adjustment board however.
 
After getting everything set according to the book and "feel" would fine tuning with an infrared temp sensor be of any benefit?

John
 
I only use the temp sensor to check to see if any brake is dragging. Not much use for fine tuning.
 
You could use your temp gun if you like, probably wouldn't hurt anything.

I think a dragging brake can be felt, heard when spinning the wheels or even rolling the car.

I 'fine tune' the brakes just by testing them. I don't want it to shuck or jive and I like both rears to lock at the same time and both fronts to drag and lock slightly after the rears and stop the same. I adjust till they do. But, maybe thats just me.
 
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