'33 Ford mechanical brake question

[Jersey Suede]

I am venturing into my first mechanical brake revamp and have a question. I notice that the front brake levers seem to have a lot of play in them, an inch or more, before there is any resistance against the brake shoes. Is this normal?

If not, my brain feels that the front brake shafts are too short and may be worn and should possibly be replaced, but it seems like an awful lot of wear to allow the brake levers to have that much free play. Then I read something about "pills" to take up the slack. Huh? I'm stumped.

I've attached a Photoshopped image of the arm to show the amount of play.

Any help is appreciated.

[DavidG]

There should be zero free play. Free play is eliminated by adjusting the clevises on the back end of the front brake rods.

[Jersey Suede]

I understand how the clevises on the brake rod will eliminate any play once they are attached to the brake levers, but it seems odd to have that much free play in the brake levers to begin with. The rear brake levers have zero play in them without the brake rods attached. I figured that is the way the front should be. Correct?

[Brian]

Yes, when you're pushing the lever forward, you will find that much play...but you need to pull the lever back, [towards centre of car],remove that slop and adjust clevises accordingly.
On the rear, you'll have return springs which are effectively holding the cam in correct place...if you push the lever [towards rear of car], against that spring action, you'll find play too.

[Jersey Suede]

Brian and DavidG, Thanks for that info. I will continue to work with these brakes and go from there. I appreciate all the info so far. It's fun to learn about these old Fords.

[DavidG]

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With respect, there are only two springs in the entirety of an original '33 passenger car/commercial vehicle brake system. One is the return spring for the pedal and the other on the cross shaft mounted on the center cross member. There were no return springs on the rear brakes. The spring on the cross shaft retracts both the front and rear brake rods equally.

Apart from the fact that the front brakes wear somewhat faster than the rear brakes, one other possible reason for a disparity between the free play between the front and rear brakes could be that your front brake rods were changed at some point in the past and they are now longer than the originals.

[Jersey Suede]

Originally Posted by DavidG

With respect, there are only two springs in the entirety of an original '33 passenger car/commercial vehicle brake system. One is the return spring for the pedal and the other on the cross shaft mounted on the center cross member. There were no return springs on the rear brakes. The spring on the cross shaft retracts both the front and rear brake rods equally.

Apart from the fact that the front brakes wear somewhat faster than the rear brakes, one other possible reason for a disparity between the free play between the front and rear brakes could be that your front brake rods were changed at some point in the past and they are now longer than the originals.

So can anyone tell me the length of the front brake rods on a stock 1933 Ford? Give or take an inch to account for the clevis adjustment?

[Jim in Wisconsin]

Mine are 53 inches pin to pin. The actual rod without the clevis is 52.

[FlatheadTed]

Often due to drum and lining ware the clevis will go past centre when pulling the rod and clevis together. With brakes adjusted at the top so the drum only just rotates the clevis should be about a 1" forward, if not the kingpin rod needs to be lengthened or thicker linings used .Ted

[DavidG]

Or the drums are worn to the point of being too thin to be safely usable.

[woodiewagon46]

I just finished a mechanical brake rebuild on a Model A. One suggestion I can give you is to not compromise on the rebuild. I replaced every component. Every shaft, bushing, cam, ETC was replaced. Every 1/32" to 1/16" of "slop" in the system will add up. I also replaced all the drums with cast iron drums. If all is tight and adjusted properly you should not have to use the brake rod clevis to account for slack in the system.

[woodiewagon46]

One other thing I can suggest is to try to use NOS parts, if possible. Most of the reproduction parts now available are junk. For example 6 of the 16 required brake shoe rollers were too tight for the pins to fit, I had to ream them. Also, the cad plating on one of the operating levers was also too thick and had to be sanded for a proper fit. If you mike up all the parts it's amazing how different they are from Ford. Oh, by the way the "pills" you mention have nothing to do with the brake rods. The "pills" go into the operating wedge, to take up slack of the brake operating pin.

[cas3]

you have turned the square adjusting shaft in to adjust the shoes first?

[G.M.]

You need to get the FORD service bulletin for adjusting 1933
brakes and follow the instructions step by step. With good drums
and linings all four wheels will slide on concrete at 45 MPH.
G.M.

[DavidG]

Pages 2 through 5 of the June, 1932 Service Bulletins (which apply equally to '33 and '34 brake systems). The complete 1932 Service Bulletins are widely available in reprint form for $15 or less.

[carguybill]

I found the same excessive forward movement of the brake lever with the rods not attached. in my case on my '34 it was about 3/4". I believe this extra movement is the way the system was designed, but I don't know why. My guess is that Henry had a good reason.

The rod that you are referring is the rod inside the brake assembly that pushes against the lower wedge. Tom said that this rod is 7 3/4" long and they can be lengthened if necessary by adding some weld to the end of them. He also advised that some of the new rods that are available are too short.

Ted also said that the front brake levers should be about 1" forward of the shackle when attached to the brake rods and should not go over center with the brakes applied. I hope this helps.

[DavidG]

With respect, you're risking life and limb if all four brakes do not engage at the same time. That's the inherent advantage of hydraulic brakes and why out-of-adjustment mechanical brakes lead some to believe that they are inferior.

[carguybill]

Originally Posted by DavidG

With respect, you're risking life and limb if all four brakes do not engage at the same time. That's the inherent advantage of hydraulic brakes and why out-of-adjustment mechanical brakes lead some to believe that they are inferior.

Back in the 50's when I was building hot rods for folks I would always discard the mechanical brakes and install the hydraulic brakes. It was easier to keep in adjustment, it was what people preferred, and it was easy to install.

That said, however I have never experienced a complete loss of brakes with the mechanical system but I have, a few times, found myself with no brakes at all with the hydraulic. Usually rusted lines on old cars but also master cylinder failure.

I also believe that a properly adjusted brake system will apply braking to the front wheels first in slow braking and the rears will come into play later with hard stops.

[DavidG]

Ford's adjustment instructions for its '32-'34 brakes included a road test to ensure that all four brakes locked at the same time. Having had sixty Fords with mechanical brakes over the years, I've found that to be good counsel.

[JSeery]

Dave, not sure about mechanicals, but with most brake systems you want the rear brakes to be delayed. This is normally accomplished with a pressure delay to the rear brakes. In a panic stop you would want all 4 brakes to lockup, but you would still want a slight delay (in pressure) to the rear brakes. But again, not sure they were that suffocated with the mechanical brakes.