Front Brake Drum
 

My Model A car club had a spring tuneup day Saturday. On my left front the adjuster is almost all the way in. There is probably less than a thousand miles since I redid the complete brake system on the car. I did not change any of the brake drums as they all measured well within tolerances. I was careful in measuring. That was about the only thing I did not change except I put new linings on the original shoes. This is the only wheel I have this problem. I asked one of the 'experts' who just from looking at the adjuster said the drum must be too thin. He did not look at anything further other than seeing that with the brake pedal pressed that one wheel does lock.

Does this mean automatically the drum is too thin and needs to be replaced? I never used a centering tool and never tried bending the roller tracks which had been suggested previously by someone else but some people say should never be done.
Appreciate any suggestions. Thanks!

Re: Front Brake Drum
 

the drum is only to thin after cking it with a drum gauge/// inside micrometer...

are you talking front or rear brakes;;;;;

you can search through the barn specifically look for purdy swoft posts regarding setting up the brake rods etc...

Re: Front Brake Drum
 

here i did the search for you read post #5

http://fordbarn.com/forum/showthread.php?t=158410

Re: Front Brake Drum
 

Thanks.
When I did the brake job I measured with a micrometer and all the drums were well within tolerances. It is the front (left) brakes.

I looked at the post you provided a link to. I am now confused. What does the rods have to do with the adjuster wedge being all the way in?

Re: Front Brake Drum
 

Maybe the brake adjusting shafts (A-2042) are too short. About the only way that would happen is if someone ground on them, but it has happened. Other parts that can cause you problem is the wedge that pushes the rollers has been ground on, or the rollers are too small a diameter. As far as one wheel not locking before the other front wheel, make sure the push rod is the correct length also. The brake rods are adjusted after all the parts are made correct inside the brake drum. As Mitch said start by measuring the drum inside diameter.

Re: Front Brake Drum
 

Maybe my first post was not clear. I never said the one wheel locks before the other wheels. Only that, that specific one wheel (and no others) was checked and did lock when the brake pedal was pressed. So there is most definitely contact between the pads and the drum and not something completely messed up in the wheel.

And again I am confused on the focus on the rods. Isn't it true that normally on a new brake system, that you could completely disconnect the rods from the wheel and tighten the adjuster wedge and at some point the wheel will lock when the pads & drum make contact?

Re: Front Brake Drum
 

Oh. Once again:
When I did the brake job I measured with a micrometer and all the drums were well within tolerances. This wedge adjuster was like this since I did the brake job and measured the drum thickness.

Re: Front Brake Drum
 

When you say the drums were well within tolerances did you measure the drum diameter or the thickness of the drum material??

Bob

Re: Front Brake Drum
 

Thickness measured with a micrometer

Re: Front Brake Drum
 

I have never seen a "thickness" number from a source that I trusted. I always go by inside diameter.

Charlie Stephens

Re: Front Brake Drum
 

Then the drum could still be oversize, you need to measure
the diameter with a drum mike.

Bob

Re: Front Brake Drum
 

I have a Drum Micrometer same as the one pictured above. IF you are in So Cal I can measure your Drums for free.

Re: Front Brake Drum
 

i have a few of those also .....

Re: Front Brake Drum
 

I am in North Carolina.

Re: Front Brake Drum
 

Take your drum to a brake shop they will give you a measurement.

Re: Front Brake Drum
 

The long and short of it is that there is some element of the mechanics of the brake that is taking up the adjustment of the brake. Look at the wedge, the roller track and the pin. Compare these parts with parts that are known to be within spec. The answer could be as simple as inserting a pill in the wedge or as complex as worn bushings in the brake shaft. Work backwards from the thickness of the brake shoes and drum to the point of something not fitting correctly or being worn beyond use.

Re: Front Brake Drum
 

When you adjusted the front brakes did you use the adjuster and screw it in until the wheel locked, then back it out a few clicks until the wheel turned with just a slight drag? After doing that to both front wheels, you then lightly push the brake lever towards the rear while you pull the long brake rods lightly toward the front. This takes out the freeplay, and you then adjust the clevis so the pin just slips into place. Done this way you should have good front brakes. Do the same for the rear brakes.

Re: Front Brake Drum
 

You could try swapping the drums left---right, if the right drum fits on the left without backing out the adjuster look for a problem in the shoes/hardware/backing plate, if you have to back it off a lot look closer at the drum

Re: Front Brake Drum
 

What kind of micrometer did you use? Unless you use one with round ball shaped ends you will not get a true reading of the thickness because of the circumference of the drum. Plus add into that the thickness of paint, rust etc. Take the drum to a brake shop and have them check it.
Someone correct me if this is wrong but I think the number is 11.060 inches wear max, 11 inch new.

Re: Front Brake Drum
 

Deleted. I stand corrected. See next post.