Adjusting Brakes for a 39 – 41 Ford

[gvgehrig]

Need help; can’t seem to get it right. First, both lower cams must be turned in wrong direction approximately 45 degrees to get the hub to mount, and they have very little movement either way before locking the drum. Second, the instructions and theory on how to adjust is straight forward – adjust the bottom then the top, then repeat until the shoe is centered. When I do it, I have to turn the bottom cams in the wrong direction to get the drum to spin and the top cam does not seem to adjust much at all, requiring a large amount of turning. Worse the sweet spot seems to keep changing. I can adjust the top cam until the drum stops, back off, then try to return to the same position to stop the rotation, but I must go to another position to stop the rotation. For some reason, the rear brakes seem to be working properly, but the front brakes do not hold their adjustment. After doing the best I can and taking it out for a test drive, the front brakes need adjusting again, putting me back to square one, i.e. I am not making any progress. I’ve pulled the whole thing apart, studied how it works, verified all parts are serviceable, and I can not determine why I can’t get a predictable outcome when making adjustments. Any ideas? Thanks

[19Fordy]

Are the lower brass cam adjusters installed correctly? Are they worn out? Did the brakes hold adjustment before this? Were the shoes installed correctly? Also, I have read other threads where some of the replacement brake shoes being made today DO NOT have the lower holes for the lower adjuster correctly located. Compare your new news with your old to see.
Also, read all this info.
https://www.google.com/search?q=1940...hrome&ie=UTF-8

According to the instructions above what you say here is incorrect. "Second, the instructions and theory on how to adjust is straight forward – adjust the bottom then the top, then repeat until the shoe is centered".

STEP 1 Directions say to adjust the top cam first, then the bottom.

Here's how I always adjusted my 40 brakes. I used a bathroom scale, a short piece of 2 x4 between the brake pedal and a piece of plywood against the front of the seat bottom to achieve poundage required.
Just for the heck of it, very carefully run through the adjustment procedure with the drum removed and see what is actually happening, GO SLOW and WATCH CLOSELY. Make sure emergency brake is released. Hope this helps.

[KGS]

The late Paul Garrigan authored "Rumbleseats Flathead Tips".
What follows is his way of adjusting the "Lockheed" brakes for 1940 Fords.
Hope this helps'
Ken


************* ADJUSTING BRAKES **************
ADJUSTING ANCHORS ON ’39-‘41 FORD/MERC BRAKES: These are Ford Lockheed
(not Bendix) brakes and use special brass washers in conjunction with
eccentric anchor bolts to position the shoe. The top of the shoes are
controlled by eccentric cams. The anchor bolts at the bottom of the
backing plate control the shoe position by rotating eccentric washers at
the bottom of the shoes. Before starting to adjust, verify all anchor
bolts turn freely.
The ’39-‘4 use anchor bolts which have locating marks (either a dot or an arrow
for position reference) indented on the elongated ¼” head of the bottom adjusting
bolt. These anchor bolts extend through the backing plates from the drum side
and are adjusted externally after loosening their large external lock nuts.
After adjusting the shoes, the adjustor lock nuts are tightened without
permitting rotation of the anchor pin adjusters.
(1) Always rotate the wheel in the same direction the wheel turns as when the
car moves forward.
(2) Begin by backing all the way off, the two 11/16” eccentric adjusters at the
top of the backing plate until the wheel turns freely. Then slightly loosening
both bottom anchor bolt lock nuts (3/4”) on the back of on backing plate. Turn
all of the two elongated locator marks (either an arrow or a dot) on the 1/4"
adjusters so they face each other.
(3) Further adjustments are made by turning the anchor bolt adjusters in a
SPECIFIC direction.....
(a) Driver’s side. The front shoe anchor ¼” adjuster bolts (with
the dot or arrow) on the both the front and rear wheels are rotated
counter-clockwise when looking at the back of the backing plate. The rear
shoe anchor ¼” adjuster bolts (with the dot or arrow) on both the front
and rear wheels are rotated clockwise. This is VERY important.
(b) Passenger side. The front shoe anchor ¼” adjuster bolts (with
the dot or arrow) on both the front and rear wheels are rotated clockwise
when looking at the back of the backing plate. The rear shoe anchor ¼”
adjuster bolts (with the dot or arrow) on both the front and rear wheels
are rotated counter-clockwise. This is VERY important.
(4) Now turn one of the upper adjusting 11/16" eccentric cams until the wheel
cannot be turned. Adjust its 1/4" anchor bolt in the correct direction until the
wheel just does turn. This lowers the shoe and moves the toe of the shoe away
from the drum, which will result in fuller shoe contact.
(5) Repeat step (4) over and over on the same shoe until turning the anchor bolt
will not free-up the wheel.
(6) Back off the upper anchor pin very slightly until the wheel will just barely
turn. Tighten the anchor pin lock nut (3/4”) and then adjust to the other shoe
on that wheel.
(7) Thereafter, it’s common to never needing to adjust anything other than the
top eccentric cam.
TIP: If you’re installing new shoes, which have been arc-ground to fit the
drum, you normally will not have to go through the preceding exercise. Turn the
dots/arrows until they’re facing towards each other and tighten the ¾” anchor pin
nuts. This correctly positions the brake shoes and you don’t have to go through
the anchor pin adjusting..... just adjust the upper 11/16" cam adjusters.
ADJUSTING ’42-’48 BRAKES: The anchor pins are different than the ‘39-
’41 Lockheed brakes, but do not have any reference marks on the backside
of the anchor bolts. And they adjust differently. Instead they have one
flat side ground on their large round shallow bolt heads. The flat sides
are turned so they face each other. This is usually al the adjustment
needed due to the semi-floating design of the anchors. Tighten the large
nuts (which are on the inside of the brake drum)and put on the brake drum.
Adjust the upper eccentric cams and you’re through.

[gvgehrig]

Thanks. I read those instructions and compared with another set which said the same except but did not say to apply brake pressure. I did chose to use the other instructions. I'll try it with brake pressure. I cannot set the anchor pin marks facing each other and get the drum on; they must be turned up about 40 degrees. If drilled incorrectly, this would seemed to be an issue. Unfortunately, I gave away the old shoes, so I can't compare. Item six is one of my main issues. I can't back off and free the drum with a "slight" adjustment. This critical point seems to move on me. I know it doesn't seem to make sense, but it is what is confusing me. Thanks for the documentation. I'll try it this morning and report back.

[gvgehrig]

Thanks KGS. These are the instructions I used. Item 2 will not work for me; in this position, I cannot get the drum on. Once on, I cannot turn to this position as there is not enough movement in the cam. From reading the instructions (both), I get the impression there should be a firm "feel" for setting the shoe in the drum. Adjusting the top does not get the response indicated in the instructions. I cannot "back off a bit" to free the drum. Also, 3(a) says the direction of the turn is "VERY" important. This has me very concerned because I cannot maintain just that direction and get the shoe to set. Thanks. I know it sounds simple, and it may be simple once I figure it out. Right now, it's just not working for me as described.

[19Fordy]

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I remember reading in a tech manual a long time ago that stock 1940 Ford brake shoe linings were .18 in thick. Are your linings oversize?

[Charlie Stephens]

Originally Posted by gvgehrig

Thanks KGS. These are the instructions I used. Item 2 will not work for me; in this position, I cannot get the drum on. Once on, I cannot turn to this position as there is not enough movement in the cam. From reading the instructions (both), I get the impression there should be a firm "feel" for setting the shoe in the drum. Adjusting the top does not get the response indicated in the instructions. I cannot "back off a bit" to free the drum. Also, 3(a) says the direction of the turn is "VERY" important. This has me very concerned because I cannot maintain just that direction and get the shoe to set. Thanks. I know it sounds simple, and it may be simple once I figure it out. Right now, it's just not working for me as described.

Did you have the shoes arced to fit the drums? I once bought a set of relined shoes. They drums wouldn't go on. The problem was I had NOS drums and all of the companies doing relining assumed everyone would have drums out at least .030. I sent the shoes back and they arced them, after which it worked fine. May not be your problem but consider it if the drums won't go on.

Charlie Stephens

[philipswanson]

I had the same problems as you adjusting my rear brakes on the 40 wagon. On the front, I went with the Bendix and never looked back. They are great. On the rear I just ignored all the printed directions from everybody because they never worked the way they all said they worked. I ended up just setting them so they would spin and not drag. And yes I had the rears relined with original linings and arced. My advice is just ignore ALL the instructions and adjust them with minimum drag. And go to Bendix (Lincoln) brakes up front.

[hope]

Originally Posted by gvgehrig

Need help; can’t seem to get it right. First, both lower cams must be turned in wrong direction approximately 45 degrees to get the hub to mount, and they have very little movement either way before locking the drum. Second, the instructions and theory on how to adjust is straight forward – adjust the bottom then the top, then repeat until the shoe is centered. When I do it, I have to turn the bottom cams in the wrong direction to get the drum to spin and the top cam does not seem to adjust much at all, requiring a large amount of turning. Worse the sweet spot seems to keep changing. I can adjust the top cam until the drum stops, back off, then try to return to the same position to stop the rotation, but I must go to another position to stop the rotation. For some reason, the rear brakes seem to be working properly, but the front brakes do not hold their adjustment. After doing the best I can and taking it out for a test drive, the front brakes need adjusting again, putting me back to square one, i.e. I am not making any progress. I’ve pulled the whole thing apart, studied how it works, verified all parts are serviceable, and I can not determine why I can’t get a predictable outcome when making adjustments. Any ideas? Thanks

Ben having the same problem, getting so frustrated after trying and trying' that i have to step away for sometime!!!!!!!


Hope

[gvgehrig]

Well, just discovered the problem. Wheel cylinder is holding hydraulic pressure. Whole new set of problems. Thanks for the help

[19Fordy]

There were some threads on Fordbarn last year about off shore wheel cylinders that were
not properly made. Could that be your problem?

[V8COOPMAN]

Originally Posted by gvgehrig

Well, just discovered the problem. Wheel cylinder is holding hydraulic pressure. Whole new set of problems. Thanks for the help

I didn't catch whether it was fronts or rears that you're working on, but a lot of times when a wheel cylinder won't relieve pressure like that, the flexible hose between that wheel cylinder and the MASTER cylinder has collapsed internally, causing a check-valve type of situation. DD

[philipswanson]

Run Bendix brakes up front. You won't regret it.

[V8COOPMAN]

A lotta wanna-be types in some of these threads throwing-around some well-worn internet "buzz-words" instead of offering some legitimate, experienced information to maybe help a guy find a REAL answer to his immediate question. That beats the hell out of throwing-around some alternative, updated replacement system as a fix-all! Just sayin'....! DD

[flatheadmurre]

Originally Posted by V8COOPMAN

I didn't catch whether it was fronts or rears that you're working on, but a lot of times when a wheel cylinder won't relieve pressure like that, the flexible hose between that wheel cylinder and the MASTER cylinder has collapsed internally, causing a check-valve type of situation. DD

Or the mastercylinder has been adjusted so it don´t return all the way back to unloaded postion...have been called out to tow people for that reason.
After a bit of crawling under the car they can drive home again !

[V8COOPMAN]

Originally Posted by flatheadmurre

Or the mastercylinder has been adjusted so it don´t return all the way back to unloaded postion...have been called out to tow people for that reason.
After a bit of crawling under the car they can drive home again !

Now we're gettin' somewhere. Another great thought, murre! DD

[gvgehrig]

Thought I'd give those kind enough to help an update. Couldn't locate the issue, so I decided to do a complete rebuild. In the process, I learned I had a multitude of issues. The cam washers on the anchor pins were .015 undersize of the shoe metal. Tightening the anchor pins inconsistently was causing mixed reactions when trying to locate what I thought was a single problem. I made washers .025 that prevents the shoes from locking the shoes based on the pressure of the anchor pins. Also, the shoes were not arched. In fact, they were way out due to too many turning of the drums. I cut off a grade 8, 5/16" bolt to a total length of a little over 1/2". With a hydraulic press, it was easy to press dimples along the inside edge of the brake shoe to stretch the shoe to an almost perfect position. Light sanding of the liners made a perfect arching of the drum. Total cost for this fix was less than $1.50 and about 5 minutes per shoe. I purchased a remanufactured master cylinder to install. Mine was, in fact, sticking and not releasing the pressure properly. In the for-what-it's-department, the yellow instructions are the best. With properly arched shoes, adjusting the anchor pins and cams is much simpler when adding hydraulic pressure. Time will tell if I have really solved all my problems. The best advice I got was to pull everything apart, study how every part works until it is fully understood, then mic everything to make sure all parts are compatible. It's been a project. Thought it was going to be a simple adjustment. Wow, was I wrong. Thanks again for all the help. It was definitely appreciated.

[V8COOPMAN]

Originally Posted by gvgehrig

Thought I'd give those kind enough to help an update. Thanks again for all the help. It was definitely appreciated.

Now THAT Sir is an UPDATE! It's too often that several here on the forum go out of the way to help someone work their way through a tough problem, only never to hear back from the guy as to the final resolve, or what it took to get him back on the road. I can tell ya that several of us appreciate this detailed update. If nothing else, it helps others to troubleshoot future problems of a similar nature. DD

[tubman]

I agree completely. Thanks for the detailed information.

[19Fordy]

Just one more point. I find Speed Bleeders to be very helpful. They do work.
Get the long ones to make it even easier.
Read post #12 here:
https://www.fordbarn.com/forum/showt...speed+bleeders