brake adjustment tool--UPDATED

[Sam Buchanan]

In a previous thread I showed how I made a brake adjustment tool using a length of steel tubing, some all-thread and a piece of angle. The tool worked fairly well but had some inherent imprecision due to the tubing not being a real tight fit on the axle threads. This was really obvious on the rear axles due to the threads being worn.

 

I've modified the tool and it now works very nicely and accurately. Instead of the all-thread being welded to steel tube, it is welded to a 3/4"-16 nut. This removes any significant play in the indicator. Before removing the wheel drum, one minor cam adjuster is tightened enough to create noticeable drag on the drum. The drum is then removed and the brake tool is threaded onto the axle. 

 

 

 

 

 

The pointer is located over the portion of the shoe that contacted the drum which indicates the ID of the drum and adjusted for a snug fit on the shoe. If you want to get really fancy a 0.006" feeler gauge can be inserted between the pointer and shoe. I tried chalking the shoe to assist with indicating the high point during the initial adjustment but didn't find it to be of any advantage. Notice how these brand new shoes have not yet worn enough to have full contact with the drum. I'll readjust the brakes after some miles have accumulated on the shoes.

 

Once the pointer is adjusted to match the high point of the shoe that was adjusted against the drum, the tool is swept over each shoe so the major and minor cam adjustments can be set so each shoe is concentric with the drum. Hopefully this will remove some of the mystery of adjusting the brakes and provide visual confirmation of proper adjustment.

 

Edited April 4, 2023 by Sam Buchanan

[casper50]

Nice ingenuity and tutorial Sam.

[chrysler1941]

Very nice but is this a new nut? If so from where and size?

[Sam Buchanan]

8 minutes ago, chrysler1941 said:

Very nice but is this a new nut? If so from where and size?

 

Yes, new and purchased from an Amazon vendor, also available at McMaster Carr. It is 3/4"-16, you might find one at a good auto supply house or in the axle nut junk box of a gearhead. If using an experienced axle nut be sure the threads are still tight. The big-box stores will probably only have the course-thread 3/4"-10.

Edited May 16, 2019 by Sam Buchanan

[chrysler1941]

3 minutes ago, Sam Buchanan said:

 

Yes, new and purchased from an Amazon vendor, also available at McMaster Carr. It is 3/4"-16, you might find one at a good auto supply house or in the axle nut junk box of a gearhead. The big-box stores will probably only have the course-thread 3/4"-10.

Thank you ?

[leadheavy52]

Excellent idea! Thanks for sharing! I will be tackling my brakes very soon.

 

-Austin

[51_Meadowbrook]

Great tool. What are your plans for adjusting the rear brakes? They don’t have a shaft to screw onto right?

[Sam Buchanan]

1 hour ago, 51_Meadowbrook said:

Great tool. What are your plans for adjusting the rear brakes? They don’t have a shaft to screw onto right?

 

The nut will thread onto the rear axle just as it does on the front.

[JSabah]

Great idea... thank you. Picked up a nut at a specialty store while getting some other items for $2.03. Had the rest in my junk bin ( I hate to call it junk ‘cause it often saves the day or at least a trip). After about 20 minutes I was under way adjusting.... thanks for the tutorial 

 

 

[Dave Gregson]

Hi Sam, great information. I have a semi assembled car and starting from scratch with the brakes. Do you have a approximate starting position (measurement)? I’ll fab up one of your adjustment tools today. 
Cheers from Australia, Dave 

[Booger]

I dig it but have never made major adjustment everything works fine for minor adjustment from back of drum

Until I go discs

['41 Fat Bottom Girl]

Just in case this helps...Here is a great alternative if you have trouble fabricating a gauge-

A few years back I originally made a gauge (thanx, forum members, for the tips on how to construct one) but I had trouble getting the play out to get an accurate feeler gauge setting.  I don't have proper tooling to make a more accurate one, so I was getting frustrated.. then talking with a buddy, he sent this to me and the procedure worked really well. As per the attached Instruction, I cut slots in the back of the hex adjusters with a hacksaw (parallel to the hex adjuster flats) so I could use a screwdriver to turn them in and out from the back of the backing plates with the drums on. 

Not difficult to do at all, you just need to take the hex adjusters out to cut the slots, and then fully reassemble the brakes and and do a rough adjustment of the adjusters to allow the drums to be installed. Adjustments can then be done from the back of the backing plate.

This got me really close, and after the brake shoes seated a bit I just readjusted the minor cams at the top of the shoes.

I have great brakes, no pulling on hard braking, and I didn't need a special tool.

 

Good Luck & Happy Motoring!

Bruce

Early Mopar Brake Adjustment.pdf

[TodFitch]

39 minutes ago, '41 Fat Bottom Girl said:

Just in case this helps...Here is a great alternative if you have trouble fabricating a gauge-

A few years back I originally made a gauge (thanx, forum members, for the tips on how to construct one) but I had trouble getting the play out to get an accurate feeler gauge setting.  I don't have proper tooling to make a more accurate one, so I was getting frustrated.. then talking with a buddy, he sent this to me and the procedure worked really well. As per the attached Instruction, I cut slots in the back of the hex adjusters with a hacksaw (parallel to the hex adjuster flats) so I could use a screwdriver to turn them in and out from the back of the backing plates with the drums on. 

Not difficult to do at all, you just need to take the hex adjusters out to cut the slots, and then fully reassemble the brakes and and do a rough adjustment of the adjusters to allow the drums to be installed. Adjustments can then be done from the back of the backing plate.

This got me really close, and after the brake shoes seated a bit I just readjusted the minor cams at the top of the shoes.

I have great brakes, no pulling on hard braking, and I didn't need a special tool.

 

Good Luck & Happy Motoring!

Bruce

Early Mopar Brake Adjustment.pdf 250.6 kB · 13 downloads

Instead of the PDF printed from my web site you could have just linked to it.

 

https://www.ply33.com/Repair/brakes

[RobertKB]

2 hours ago, TodFitch said:

3 hours ago, '41 Fat Bottom Girl said:

Not difficult to do at all, you just need to take the hex adjusters out to cut the slots, and then fully reassemble the brakes and and do a rough adjustment of the adjusters to allow the drums to be installed. Adjustments can then be done from the back of the backing plate.

This got me really close, and after the brake shoes seated a bit I just readjusted the minor cams at the top of the shoes.

I have great brakes, no pulling on hard braking, and I didn't need a special tool.

 

Early Mopar Brake Adjustment.pdf 250.6 kB · 16 downloads

 

I’ve done that on all my old Mopars. It works well and all my cars have good brakes.

I locked the brakes up on my ‘51 when an idiot in a semi turned right in front of me so I know they work well!!

Edited July 4, 2021 by RobertKB

['41 Fat Bottom Girl]

Thanx, Todd-

I didn't know where this had originally had come from. Thanx for letting me know, credit always MUST to be given where credit is due. No plagiarism intended, I got it from an article sent to me, not from your site. Please accept my apology- and many thanx for the valuable info! 

Good lesson to be careful to verify one's sources when possible. Regards,

Bruce 

[TodFitch]

No problem. You mentioned it was emailed to you. And looking at the PDF, whoever created it stripped off the information about the original source so there was no way for you to know.

[Ernie Baily]

Hello,  I just made the tool. My question is how do I start the measurement? My brakes are squealing and pulling. I presume my drums are already turned out probly to far. So I guess I would just use some emery cloth to clean up the drums and find someone to true the linings. Any tips and advice would be a great help.

 

 

Thanks

Ernie Baily

[Eneto-55]

21 hours ago, TodFitch said:

Instead of the PDF printed from my web site you could have just linked to it.

 

https://www.ply33.com/Repair/brakes

I think I may also have that PDF someplace on my computer (or as a guy on another forum calls it, "the confuser"), but I don't know if I got it from someone else (as this poster did), or if I was pointed to your site.  I went there now, and I see the copyright notice on the header of your website, but I'd suggest you make that source note & copyright notice a part of the download itself.  That would help innocent users to remember where it came from, and give the proper credit.  We all copy lots of stuff that seems like it might be something we will need at some point, but our memories don't always serve us well when it come to recalling where it came from.  I often copy material directly from websites (where there is no PDF download option available), and have learned that if I ever hope to find the source again, or tell someone else where it came from or how to find it themselves, I MUST make all of that a part of the document I am creating. 

Just the other day I found an excerpt from an old periodical, and it was already a scan, but not a PDF I could download.  I haven't done it yet, but I plan to type out the text, and insert the figures (which I captured with the Windows Snip tool as .jpg files) into the retyped text.  The on-screen version was so small and fuzzy that I couldn't read it easily, so hoping that by enlarging it, I can make it all out.  But I DID note the name of the periodical, the volume number, and the pages where the article originally appeared.  I've learned that just because something is on the internet now does not mean that it will be later, or even tomorrow.  (A good example of this is all of the photos that Don Coatney posted links to, links that are now broken because those photos are no longer on the site where he was hosting them from.)

 

AND, my thanks as well for making this information available.

Edited July 5, 2021 by Eneto-55

[TodFitch]

2 hours ago, Eneto-55 said:

I think I may also have that PDF someplace on my computer (or as a guy on another forum calls it, "the confuser"), but I don't know if I got it from someone else (as this poster did), or if I was pointed to your site.  I went there now, and I see the copyright notice on the header of your website, but I'd suggest you make that source note & copyright notice a part of the download itself.  That would help innocent users to remember where it came from, and give the proper credit. . .

Actually if you print that page (or print it to PDF) you will get the attribution and copyright information in the file. I think the PDF that is circulating was created by someone copy and pasting rather than downloading. Not much that I can do if they decide to not copy and paste the attribution and copyright.

I suspect they did the copy and paste because if you print or print to PDF you get the thumbnails rather than the full images. It has been a while since I looked into the formatting (via CSS) to see if the print style can use different image links than the display style. That might be worth looking into.

['41 Fat Bottom Girl]

Hi Ernie-

Finding somebody that has an arc machine these days can be difficult depending on where you are.

And turned drums or replacements can have different inside diameters, so it is important to arc each front and rear shoe pairs to match the drum in which they will be installed. 

Regarding arcing the brake shoes- I could not find one of the threads from a few years back that described an alternative, but FYI...Let me paraphrase:

There is another method you can easily do yourself without the need for finding somebody that has a machine, and/ or sending the drums and shoes out to have it done. This method will size your shoes pretty close to the drum diameters, and after running in the shoes for a while, they will match the drum almost perfectly (if you do your initial clearance adjustment carefully) and then do another follow-up adjustment again after the shoes run-in a while. 

Do Not Inhale Brake Shoe Dust- Wear a mask when sanding!

 

1) Identify a front and rear shoe pair that will be used for each drum. They will be drum specific as previously mentioned.

2) Clean the shoe contact diameter of the drum free of grease, dirt or oil.

3) Cut strips of sandpaper a bit wider than the shoes and longer than the shoe lining length and adhere them to the inside the drums using thin double-faced adhesive tape. The adhesive or tape should cover the full back surface of the sandpaper strips. Ensure the sandpaper is flat and even to the drum surface, no wrinkles. 

( I use 150 grit so the caliper over the paper and adhesive isn't any thicker than necessary, which would make a smaller radius on the shoe than desirable. If you find there is a lot of shoe lining material to remove in order to match the drum, I have used a coarser grit to get started, and the finer grit sandpaper to finish the arcing and to better match the drum).

4) On each brake shoe lining face, with a permanent marker, draw lines across the width of the shoe lining, heel and toe and across the middle, so you can check when you start sanding that you are keeping even pressure across the width of the shoe. 

This will also give you an indication of the high spots where pad material will be removed.

5) Put a mask over your nose and mouth. Place a brake shoe inside the drum against the sandpaper, and keeping even pressure on the shoe, sand it back and forth inside the drum diameter until you can see enough material removed along the length and width of the shoe lining to match the drum curvature. Then do the opposite shoe.

6) Remove the sandpaper that was affixed to the drum, and clean the drum surface free of any adhesive.

7) Finally, if in the process of removing material from a lining you see that this has also removed the chamfers, file about a 3/32" chamfer along the leading and trailing ends of the shoe lining. This aids the shoes engagement with the drum and is easier on the lining ends while braking.

? Install the shoes and parts into the wheel backing plate and ensure that the spring is fully retracting the shoes and all looks good.  

9) Using the adjustment tool described earlier in this thread, adjust the shoes for the proper clearances (on my '41 shop manual it shows .006 at the heel (bottom) of the shoes, and .012 at the toe (top) of the shoes).

Or, if you don't have, or cannot fabricate such a tool, install the drum and use the "drag" method of Major and Minor adjustments described by Todfitch in this thread above.

(tip: Using that method, note that there are arrows on the hex adjusting nuts inside faces- When cutting the screwdriver slots on the back of those eccentric hex adjusting nuts, I cut similar arrows there too. This helped me know where the eccentric positions are after the drums went on. Your shop manual will show you the direction that the arrows should face before installing the drum and making those shoe adjustments. Rears and fronts are different. For example, on my '41 the arrows on the hex adjusting nuts are shown facing each other before the drum went on and before "drag" adjustments were made. Fronts are a different configuration. Shop manual will show you the shoes tightening and loosening rotation directions).

 

Hope this helps and the description is ok, please ask questions if something isn't clear.

Happy Motoring!

 

 

  

[plymjim]

  Coincidentally, I ran across this document today regarding brakes.

Looks like a service bulletin from 1946. Sorry it's not in better shape

(especially page 1) but if anyone can use it, here you go.

[Tooljunkie]

12 hours ago, '41 Fat Bottom Girl said:

Hi Ernie-

Finding somebody that has an arc machine these days can be difficult depending on where you are.

And turned drums or replacements can have different inside diameters, so it is important to arc each front and rear shoe pairs to match the drum in which they will be installed. 

Regarding arcing the brake shoes- I could not find one of the threads from a few years back that described an alternative, but FYI...Let me paraphrase:

There is another method you can easily do yourself without the need for finding somebody that has a machine, and/ or sending the drums and shoes out to have it done. This method will size your shoes pretty close to the drum diameters, and after running in the shoes for a while, they will match the drum almost perfectly (if you do your initial clearance adjustment carefully) and then do another follow-up adjustment again after the shoes run-in a while. 

Do Not Inhale Brake Shoe Dust- Wear a mask when sanding!

 

1) Identify a front and rear shoe pair that will be used for each drum. They will be drum specific as previously mentioned.

2) Clean the shoe contact diameter of the drum free of grease, dirt or oil.

3) Cut strips of sandpaper a bit wider than the shoes and longer than the shoe lining length and adhere them to the inside the drums using thin double-faced adhesive tape. The adhesive or tape should cover the full back surface of the sandpaper strips. Ensure the sandpaper is flat and even to the drum surface, no wrinkles. 

( I use 150 grit so the caliper over the paper and adhesive isn't any thicker than necessary, which would make a smaller radius on the shoe than desirable. If you find there is a lot of shoe lining material to remove in order to match the drum, I have used a coarser grit to get started, and the finer grit sandpaper to finish the arcing and to better match the drum).

4) On each brake shoe lining face, with a permanent marker, draw lines across the width of the shoe lining, heel and toe and across the middle, so you can check when you start sanding that you are keeping even pressure across the width of the shoe. 

This will also give you an indication of the high spots where pad material will be removed.

5) Put a mask over your nose and mouth. Place a brake shoe inside the drum against the sandpaper, and keeping even pressure on the shoe, sand it back and forth inside the drum diameter until you can see enough material removed along the length and width of the shoe lining to match the drum curvature. Then do the opposite shoe.

6) Remove the sandpaper that was affixed to the drum, and clean the drum surface free of any adhesive.

7) Finally, if in the process of removing material from a lining you see that this has also removed the chamfers, file about a 3/32" chamfer along the leading and trailing ends of the shoe lining. This aids the shoes engagement with the drum and is easier on the lining ends while braking.

? Install the shoes and parts into the wheel backing plate and ensure that the spring is fully retracting the shoes and all looks good.  

9) Using the adjustment tool described earlier in this thread, adjust the shoes for the proper clearances (on my '41 shop manual it shows .006 at the heel (bottom) of the shoes, and .012 at the toe (top) of the shoes).

Or, if you don't have, or cannot fabricate such a tool, install the drum and use the "drag" method of Major and Minor adjustments described by Todfitch in this thread above.

(tip: Using that method, note that there are arrows on the hex adjusting nuts inside faces- When cutting the screwdriver slots on the back of those eccentric hex adjusting nuts, I cut similar arrows there too. This helped me know where the eccentric positions are after the drums went on. Your shop manual will show you the direction that the arrows should face before installing the drum and making those shoe adjustments. Rears and fronts are different. For example, on my '41 the arrows on the hex adjusting nuts are shown facing each other before the drum went on and before "drag" adjustments were made. Fronts are a different configuration. Shop manual will show you the shoes tightening and loosening rotation directions).

 

Hope this helps and the description is ok, please ask questions if something isn't clear.

Happy Motoring!

 

 

  

I did this, fortunately my drums arent badly worn. I use adhesive sanding strips found at body shop supplier. 
i have the paper as i do dabble in bodywork as well. Could go to body shop and buy a couple feet off a roll.