Brake Adjustment

Purdy Swoft said:
Brake adjustment is mentioned in two places in the bulletins . one for the early and another in a different page for the later more common model A brakes . . Without copying the bulletin I'll tell how I do mine . I first disconnect the brake rods at the adjustable clevis end so they will be free and ready to adjust when the time comes . I then move on to the service brake cross shaft adjustment . I disconnect the pedal rod and adjust it so that the plunger at the rear of the pedal rod is 1/16 of an inch from the inside rear of the center cross member where the plunger meets the brake light switch on the 30-31 models . This adjustment is the easy way to set the cross shaft levers pointing straight up and down as Larry Sheppard mentions in a previous post . I then prop the brake pedal at the top of its travel . I adjust the clevis on the pedal rod so that the clevis pin will just enter the brake pedal and hold it at the top of its travel . I then adjust the brakes at the adjustment wedges on the backing plates . I pull back any slack at the front brake levers and adjust the clevises on the front brake rods so that the clevis pins will just enter the front brake levers . I then move to the rear and adjust the rear service brake rods. I pull forward on the rear brake levers to remove slack . I adjust the clevises on the rear brake rods so that the clevis pins will just enter the brake levers. This setup will have all slack in the system removed and the brakes will be ready to activate when the pedal is depressed. If the inner brake parts are in usable condition the brakes will be good .[/QUOTE


Well said and explained Purdy. When you get your drag or wheel individual clevis’s adjusted at that point it’s important to get things pretty even so you don’t have a pull to one way or the other. Even a half turn can make the difference. Road test the car and break them in a little and then adjust as necessary.

Purdy, I’m doing a brake seminar at the 2018 Marc meet. Sure wish you could be there.
All the best !
Larry
Click to expand...
 
Thanks Larry for the kind words . I agree that the brakes should be tested for final adjustment at the wheels. I like to test mine in a dirt drive so I can compare skid marks .

Larry , Thanks for the invite to your seminar , I'm sure it will be very good !!!
 
An interesting point is that in the Bulletins and in Les Andrews, the initial setting of the brake rods of some precise length of 51-7/16 to 51-1/2 is mentioned as if that is some kind of precise measurement after all is said and done. I think they should point out that this is simply a beginning point and not have it down to the 16th of an inch. It leads one (at least a beginner) to think that is a final measurement. But, it was written 90 years ago, so it ain't going to change.

With all new components, I took great care to measure my brake rods only to adjust them by quite a bit in the step where you take up the slack after adjusting each individual wheel. Hopefully people don't measure their brake rods and not adjust the clevises when taking up the slack.
 
Magicbox51 said:
An interesting point is that in the Bulletins and in Les Andrews, the initial setting of the brake rods of some precise length of 51-7/16 to 51-1/2 is mentioned...
Click to expand...

The Service Bulletin on page 259 is about the redesign of the rods to a solid non adjustable type. They are the lengths specified by Andrews. :confused:
 
Actually there is REALLY NO need in measuring the brake rods at all !!!!!!! Just install the brake rods and adjust the brake rod clevis so that the clevis pin will just enter the brake levers . Because of the confusion caused by mention of brake rod length it is sometimes impossible to get this fact over to some people .
 
There was a difference in the early brake rod setup that doesn't apply to the later much more common model A's . Because of the confusion that mostly can't be overcome, many will continue to have brakes that leave a lot to be desired .
 
Purdy Swoft said:
Actually there is REALLY NO need in measuring the brake rods at all !!!!!!! Just install the brake rods and adjust the brake rod clevis so that the clevis pin will just enter the brake levers . Because of the confusion caused by mention of brake rod length it is sometimes impossible to get this fact over to some people .
Click to expand...


Yup!
 
The proper setup for leverage at the service brake cross shaft and the elimination of any slack at the brake rod connections is most important for good brakes.
 
daveymc29 said:
Went for a drive in the rain this AM and since it is the first rain in eight months or so the streets are slick as can be. Car stops real well on dry roads but the back end wanted to get to the intersection first today. Let up a bit and stopped five feet past the line instead of five feet before it. I might just put the 32 drums and brakes back on the front. They give a little more shoe contact than the 31's. 12 inch verses 11 inch. If I had a lathe I'd make some discs for the front and be done with it. Too old to start now.
Click to expand...

The Brakes and how they function and how well they stop the car, also relate to the surface area of tire to pavement.
Talking about this subject of a rain after much dry time, I too had to make a stop rather quickly. Not much surface area, a bit of slick on the road mixed oil and water and stopping without sliding was a challenge. What I learned from this was something about "not overdriving my brakes and tires!" Sadly at my age, when I get in the old girl to drive, memory of this at times escapes me! Dry pavement is one thing, but as you have pointed out, on a road where there has been no rain in a long time, the road is not your friend for quick stops no matter how good your brakes are.
 
Up here w/ice and snow on the roads for a good part of the year it's normal to feather the brakes a lot so that you're slowing down, not sliding. I don't like hearing that clk clk clk clk of the anti-lock brakes on the modern vehicles, it tells me that I'm braking too hard.
 
AL in NY said:
When I redid my brakes earlier this year, I used the "Brake Buddy" and a modified Les Andrews procedure so both front and rear brakes are applied the same
Click to expand...

Ya know, I was wondering when I adjusted mine about why the rears were set up to grab first. I did it per the Les Andrews procedure, yet, I don't know why other than it was a published procedure. I would be interested in knowing how adjusting the fronts and backs the same has worked out. I am contemplating, as a test, to adjust the fronts to engage a bit before the rears and see what kind of difference it makes. As I try and think why Henry had the rears grab first, I wonder if it had anything to do with horse drawn devices of the day only having brakes (crude) on rear wagon wheels? Just wondering! Henry probably had a more valid reason!
 
DHZIEMAN said:
Ya know, I was wondering when I adjusted mine about why the rears were set up to grab first. I did it per the Les Andrews procedure, yet, I don't know why other than it was a published procedure. I would be interested in knowing how adjusting the fronts and backs the same has worked out. I am contemplating, as a test, to adjust the fronts to engage a bit before the rears and see what kind of difference it makes. As I try and think why Henry had the rears grab first, I wonder if it had anything to do with horse drawn devices of the day only having brakes (crude) on rear wagon wheels? Just wondering! Henry probably had a more valid reason!
Click to expand...


Venturing a guess
In the day, most previous cars were rear only including the T. Pumping the Brakes was probably not an ingrained habit for stopping, most only knew about braking with rear only brakes.


Perhaps Henry was concerned about safety when braking on dirt, gravel, snow, etc.? People not knowing how to stop the quickest.
 
Dick Steinkamp said:
The upside of having the rear brakes lock first in gravel is that you will be able to steer. The downsides are that it will take a lot longer to stop and the rear of the car will likely pass you during the attempted stop. :eek:

How often will we experience a panic stop in gravel vs on pavement?

All cars since the mid 1930's have the braking proportioned so that the fronts do 75% of the braking and will lock first in a panic stop. Was Henry right with the Model A and everyone since wrong? Was Henry right with the 2 wheel brakes on the Model T?
Click to expand...


I too think the roads is the key. On gravel roads, braking the rear wheels first will help maintain control. On asphalt rods braking the front first will result in better braking as the nose tends to dive into the front axle.


When Henry built these cars they were primarily on gravel or dirt roads, not the case anymore.
 
whirnot said:
I too think the roads is the key. On gravel roads, braking the rear wheels first will help maintain control.
Click to expand...

There is no perfect front/rear bias for emergency braking on gravel roads or other slick/semi slick surfaces (other than an anti-lock brake system).

Rear brake bias on gravel roads will cause the car to change ends in an emergency stop. Front brake bias will cause severe understeer in an emergency stop on gravel roads.
 
First time I saw a car spin was a 32 tudor on the road to our ranch. The road was dry as a bone, covered in anything from fine sand to gravel a tad larger than pea gravel. This was about 1943 and the v8 began to heat so the driver had us get out and he drove to the top of the hill to await us there. He hit the brakes and the back end went to the front position and the whole car shuddered to a stop. He then drove past us and told us to wait, he'd get his dads 35 chevy pickup and take us all home, which he did without incident. I think that the engine may have also seized along with the grabbing of the brakes to stop the rear wheels and the car made an impressive about face. The young driver, probably 14 gave us a sheepish look as he rolled down the hill past us. Never saw him drive a Ford again until he was plowing one day with a 27 Fordson tractor. That is another story found in my book, http://bit.ly/FromtheShadows
Dave the Ace author
 
You must log in or register to reply here.
Back
Top