Adjusting brakes

Lawson Cox

Lawson Cox

Well-known member
Is it mandatory to have someone apply pressure to brake pedal when adjusting 39 style brakes. If so, how do you gauge 30 pounds of pressure on the pedal? Inquiring minds want to know. :D
 
get an object that weighs 30 LBS (rock, sack of cement etc.). Place a 3' 2x4 with one end on the pedal and the other under the front seat on the floor. Set the 30 LB object on the 2x4 nearest the pedal end. What do I win?
 
No photo, but "picture" this.
Place a flat piece of plywood vertically (with it's edge resting on the floor) in front of the lower portion of the front bench seat. This protects the seat and provides a flat, solid surface. In front of that place a bathroom scale vertically so it rests against the plywood.
Then wedge a piece of 2x4 (or something similar) between the surface of the bathroom scale and the brake pedal. Use a shim like a door stop to get a reading of pounds required.
Adjust the brakes as outlined in thread below.
I did install Speed Bleeders to make the job easier. I used the longer style to make wrench fit much easier.
http://www.fordbarn.com/forum/showthread.php?t=163928&highlight=adjust+40+ford+brakes
http://www.speedbleeder.com/
 
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39topless said:
get an object that weighs 30 LBS (rock, sack of cement etc.). Place a 3' 2x4 with one end on the pedal and the other under the front seat on the floor. Set the 30 LB object on the 2x4 nearest the pedal end. What do I win?
Click to expand...

Great idea. What does the end of the 2x4 that goes under the seat rest against?
 
Lawson, This is the procedure I always use.

Adjusting '39-'42 Brakes: This is from a collection of tips sent to me from "rumble seat"

I used to hate these brakes because of the adjustable double anchor when I was a mechanic in the mid fifties. Then a fellow mechanic showed me a Ford Service bulletin. Ever since then, I have preferred these to the '46-'48 units since I can get a better adjustment.

These are Lockheed brakes which use eccentric washers in conjunction with non-eccentric anchor pins to position the shoes. The top of the shoe is controlled by an eccentric cam (usually 11/16") located near the top of the shoe. The anchor pins, located at the bottom of the backing plate, control the shoe position by turning the eccentric washers at the bottom of the shoe. These anchor pins have locating on the elongated 1/4" adjuster. The locating marks may be a dot or an arrow, I'm assuming everything is in good condition and not rusty or frozen.

Step 1: Loosen the anchor pin large lock nuts (usually 3/4") on both shoes of one wheel just barley enough to permit turning the 1/4" anchor pin adjusters. Now, turn both of the 1/4" adjusters so the locator marks face directly towards each other. This next point is important .... All further adjustments are made by turning the anchor pins (1/4") and eccentric (11/16") downwards.

Step 2: Back off the upper eccentric cam adjusters on both shoes until the wheel rotates freely.

Step 3: Now turn one of the upper eccentric (11/16") until the wheel cannot be turned.

Step 4: Now turn it's 1/4" anchor pin adjuster downward until the wheel just turns freely. This lowers the shoe and moves the toe of the shoe away from the drum and results in fuller shoe contact.

Step 5: Now go back to Step 3 and do it and step 4 again to the same shoe. Repeat as necessary until turning the 1/4" anchor pin adjuster will no longer free up the wheel. Back off both anchor pin adjuster and upper eccentric just enough so the wheel has a slight drag. Tighten the anchor pin lock nut (3/4") without letting the anchor pin adjuster move. Now do the other shoe the same way.






If you've worn the shoes badly at the top, it'll take some time to wear the heel enough so you get full brake shoe contact.
When adjusting brakes, always turn the wheel in the same direction the wheel would turn when the car travels forward.

PS: The 1/4" anchor adjustment bolts require an offset open end wrench about 8 1/2" in length to get enough leverage to turn, I think it's a special Ford tool and hard to find. BillB
 
I use Kens method,time consuming but works great.Actually I believe it givs a better adjustment than the later fixed anchor type,but takes longer.Phil
 
Ken. Thanks, I have all of that info, I am just wondering if it is mandatory, for a good job, to apply pressure to the pedal while adjusting. That's all I am asking about.
 
Lawson Cox said:
Ken. Thanks, I have all of that info, I am just wondering if it is mandatory, for a good job, to apply pressure to the pedal while adjusting. That's all I am asking about.
Click to expand...

Lawson - I just have someone in the car apply what feels like 30 lbs. of pressure to the pedal ! Always has worked for me ..........:) - FF
 
Lawson, I doubt if it's mandatory, but I bet it saves time and effort as it pre-loads the brake pedal making it easier to get the right amount of fee -play in the pedal before the brakes are acutated.. Otherwise, it's all trial and error.
 
39topless said:
get an object that weighs 30 LBS (rock, sack of cement etc.). Place a 3' 2x4 with one end on the pedal and the other under the front seat on the floor. Set the 30 LB object on the 2x4 nearest the pedal end. What do I win?
Click to expand...

You can't get the full 30 pounds of downward force on the peddle with this method. Some of the force will travel down the 2x4 and against the seat. Someone who remembers their physics better than I do, could figure out the correct weight to use to end up with 30 pounds of force on the peddle.

I just ask my wife to push down on the peddle with 30 pounds of pressure and use whatever happens. It seems to work.
 
Lawson Cox said:
Ken. Thanks, I have all of that info, I am just wondering if it is mandatory, for a good job, to apply pressure to the pedal while adjusting. That's all I am asking about.
Click to expand...

I never heard of putting weight on the pedal. I must have missed
something close to 70 years ago when I started driving and working
on the A's and flatheads. Go by what the Ford service bulletins say.
G.M.
 
G.M. said:
I never heard of putting weight on the pedal. I must have missed
something close to 70 years ago when I started driving and working
on the A's and flatheads. Go by what the Ford service bulletins say.
G.M.
Click to expand...

G M - Its on page 188 of the "1939 - 1948 Ford & Mercury Service Manual for Passenger Cars & Trucks ". I only know this because I just did mine last week . :)
 
Lawson, Adjust them without pressure. All you are trying to do is center the shoe in the arc of the drum with the lower adjuster and push the shoe out with the upper adjuster.
Just turn the upper adjuster down until it drags heavily, then turn the lower adjuster until it frees up and then repeat this procedure until it doesn't free up anymore , now the shoe is centered in the drum. Now adjust the uppers to a very slight drag and your done. Pretty easy but time consuming.

Adding pedal pressure is pushing the shoe out against the drum, same effect as the upper adjuster. Bill
 
I use a 30 pd weight and hang it from the pedal under car ,to pr-load brake .

Follow the instructions that Ken posted

Looking at backing plate FROM BACK SIDE!!
FORWARD SHOE AJUSTMINT turns it clock wise ,
REARWARD SHOE turn it counter clock wise ,,on each wheel .
 
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rich b said:
The one toward the rear is clockwise and the one toward the front is counter-clockwise.
Click to expand...

19ED30 said:
Looking at backing plate FORWARD SHOE AJUSTMINT turns it clock wise ,
REARWARD SHOE turn it counter clock wise ,,on each wheel .
Click to expand...

There is some confusion about the direction of rotation of the lower anchor adjustment. Step 1 in Ken/Alabama's post says to turn both adjustments down. This depends on which direction the adjusting tool is facing. 19ED30's directions are correct according to the Motor's Manual. This would mean the adjusting handle of the top adjustment would point toward the OUTSIDE of the backing plate. The handle of the adjusting tool for the lower anchor points would point to and across the CENTER of the backing plate, necessitated by the "wall" of the indentation in the backing plate. I hope this doesn't further confuse the directions.
 
I'm coming into this one "cold" and have never heard of applying 30lbs weight to the pedal. I'm not worried about how to apply it, but could someone please tell me the reasoning why you would apply it and what it should achieve? What would be the downside of not doing it?

I've never done it so I would be interested to find out the reasoning behind it.

Mart.
 
I have found that using the 30 pound pressure on the pedal pre-loads the
pedal reducing the amount of free travel before the brakes engage.
 
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