poor brakes on our early 28 .

[Harry Lipki]

The brakes on our 28AA pepsi truck are hard to work . The shoes are new -- the linkages are free .. yet it takes 2 men and an army to apply the brake . mind you it stops easier with the brake lever (left hand ). I am new to this and do not know how to fix . Help me whoa her down ?

[spectria]

The brakes on our 28AA pepsi truck are hard to work . The shoes are new -- the linkages are free .. yet it takes 2 men and an army to apply the brake . mind you it stops easier with the brake lever (left hand ). I am new to this and do not know how to fix . Help me whoa her down ?

With mechanical brakes, it is a function of leverage. Obviously that huge long handle on the "E-Brake" (I know that's wrong somehow) is much greater than the leverage on the pedal. It would be simple to increase the leverage on the pedal by shortening the arms somewhere, but then you run the risk of running out of travel or breaking something.
I won't be trusting my existing brake rods due to their age.

Of course you will soon get input from others about how the brakes work very well when built/matched correctly, so I would first go with rechecking all the working parts to be sure Shoes and Drums are properly matched. Something about steel and woven, or cast and organic shoes... can not keep that straight in my head.

The arch of a brake shoe is very important, they must have a curve very close to curve of the drum.

I wonder if there is a leading/trailing shoe in the A/AA? Usually fixed pivot brakes have no leading/trailing shoe setup, but later brakes with moving pivots have a smaller leading shoe, and a larger trailing shoe due to the fact that the leading shoe grabs the drum and rotates to the rear, applying the trailing shoe and the leading shoe usually had a 1/3 more effectiveness than the trailing shoe, so the trailing shoe usually has at least a 1/3 more surface area.

You can feel this in most modern vehicles when you can back out of the driveway with the e-brake STILL applied, but then you can't go forward until you take the e-brake off.

[Harry Lipki]

I replaced the front woven shoes with organic . I never checked the arch . The front drums I do believe are steel . Did not need to do anything with the rear shoes or drums . They are woven on steel . Will installing woven shoes on the front help?

[REM]

I wonder if the brakes are set up so most of your braking with the pedal is occuring with the front brakes which being new and not yet contoured to the drums don't provide much stopping power while using the E-brake applys the rears which are larger and worn in to fit the drums.
Just a thought.

[Bob C]

Steel drums use woven linings. Are the tracks and rollers in good condition? The front
brake arms should be leaning forward 15 degrees from vertical. If you have a copy of the service bulletins
page 202 tells how to adjust the brakes. if you don't have a copy I suggest you get one as there
is a ton of information in them.

Bob

[Bob from Northport]

All the facts supplied about the drums and shoes are nice, but I don't think they are answering the question asked. If I hear him correctly, the pedal pressure is hard. Take the brake rod loose from the pedal under the floor, and see if it moves freely. A grease fitting can be installed on the bottom side if necessary. Check the angle on the front brake rod arms to see if it is close to a 15 degree outward position. Move each brake manually to see if they are working. Jack up each wheel and check each operation.
The shoes on a A or AA have NO trailing shoe. The shoes and linings are the same size. He is speaking of modern brakes. Lay under the truck and have someone work the pedal and watch the operation of the brake rods under the floorboards. Move the hand brake lever and see if it operates differenty. You will figure it out.

[spectria]

All the facts supplied about the drums and shoes are nice, but I don't think they are answering the question asked. If I hear him correctly, the pedal pressure is hard. Take the brake rod loose from the pedal under the floor, and see if it moves freely. A grease fitting can be installed on the bottom side if necessary. Check the angle on the front brake rod arms to see if it is close to a 15 degree outward position. Move each brake manually to see if they are working. Jack up each wheel and check each operation.
The shoes on a A or AA have NO trailing shoe. The shoes and linings are the same size. He is speaking of modern brakes. Lay under the truck and have someone work the pedal and watch the operation of the brake rods under the floorboards. Move the hand brake lever and see if it operates differenty. You will figure it out.

Harry, As Bob pointed out, I was making a comparison between A/AA brakes and modern brakes. Since Bob has cleared up the issue of all shoes per axle would be the same facing front or rear, I would go on rechecking all of the linkages as he suggested.
I also like the suggestion that the front brakes may not be seated and arched and since front brakes on all vehicles do at least 60% or more of the braking, if they aren't working well, it would have a larger impact than poorly operating rear assemblies.

Also, if the rear brakes are adjusted up tight, and the fronts have more clearance, you will run out of travel on the pedal before fully activating the fronts...

[Harry Lipki]

Well I had a quick look at my brakes this morning and noticed that the front brake levers are straight up and down and are not 15 degrees forward. I would have to asume tha is some how adjustable . I will be ordering the service bulletins for the truck today
all the other parts are free and move easily . Is there a short cut to making the arm forward ? I gues I will have to figure that one out

[Bob C]

You use what they call a pill that goes in the brake
wedge to shim it. See the link.
http://www.snydersantiqueauto.com/searc ... h&x=54&y=8

Bob

[farmerden]

I remember my Dad saying that if you had the brakes set up loaded [maybe overloaded!] then the truck wouldn't stop empty! I guess the brake rods were stretched under load and then had too much slack empty.Or maybe they had no brakes in the depression-They never had tires that's for sure -just rags!! Den

[Hardhatz]

I have experienced VERY poor brakes upon new shoe installation. One that sticks in my mind was a 66 Bonneville with normally touchy power brakes that would barely stop with all the strength of both my legs. It took some driving to scuff them in, including one run that buried the speedo followed by max brake application. After that, they were perfect.
That was when I was about 19, and I was irrational enough to do that.

Obviously the AA will not be running 120 MPH, but I'd rec some kind of break-in...

[vtwinsideways]

Obviously the AA will not be running 120 MPH, but I'd rec some kind of break-in...

It could, but it would take a jet powered tow truck!

[spectria]

Obviously the AA will not be running 120 MPH, but I'd rec some kind of break-in...

It could, but it would take a jet powered tow truck!

LOL

[mbailout2]

You can keep guessing and throwing Band-Aids on your truck, or you can get a proper publication/manual and do a complete Inspection of your braking systems. It appears you have compound problems which will keep you going in circles.

Mark

[Rosenkranswa]

I have to agree with Mark. I can slide the wheels on my AA with or without a load and without having to stand on the brakes. Properly adjusted, the Model A/AA brakes will work pretty well - but everything has to be correct. Get a good set of instructions and go through the system completely.

By the way, don't view the "Emergency" brake as really being an Emergency brake - its more of a parking brake. Braking surface area is considerably less, and its not set up to take that kind of use. Its possible to actually distort the parking brake plate in the rear hubs if you mistakenly leave the brake on and try to drive off (don't ask me how I know...).