Can't get front brake shoes to go in so drum will fit on 48 DeSoto.

[James_Douglas]

2 hours ago, desoto1939 said:

Here is another ammco more detail instruction manual.

 

Rich Hartung

desoto1939@aol.com

AMMCO Brake Arcing Tool 8000.pdf 2.31 MB · 2 downloads

Make note that the note on page 8 in this booklet and go see my earlier post on the addendum...some of the earlier machines DID NOT HAVE THE CLEARANCE BUILT INTO THE MACHINE. On the earlier machines you had to add the clearance before you set the caliper dial. I have also seen people add the clearance on the newer machines when they should not.

 

Just one of those little things that can bite you in the ass.

 

James

 

 

[James_Douglas]

Rich, Thanks for the downloads, yours are much more clear than the ones I have.  James

[Dodgeb4ya]

Another way of centering/fitting shoes to each drum after first making sure each shoe lining arc matches each brake drum.

This if you don't have shoe adjusting tooling..... ammco 1750 or Miller MT-19. Just another.old time way.

Feeler gauge is used at toe and heel of each brake shoe...

Cut a slot in each anchor bolt in line with anchor arrow...mark arrow at correct end of cut slot to match direction of factory arrow.

Use screw driver to rotate shoe anchor bolts and cams to center shoes to drum and set toe and heel clearance. Do not over loosen anchor nut. 

After adjustment pull drum to hold anchor bolt to tighten .nuts

Yellow front anchor bolt arrow is shown set to move brake shoe heel furthest from the drum....arrow is to be  pointed  thru centerline of front wheel cylinders.

This is also the original factory front anchor bolt setting.

Rear brake lower brake anchors should point at each other but just angled downward the slightest bit.

This setting pulls the rear brake shoe heels in from the drums the maximum amount.

This is also the original  factory rear anchor bolt setting.

Adjust to your liking.. your cam and anchors.

 

 

Edited February 28, 2022 by Dodgeb4ya

[MarcDeSoto]

Ok, here's the skinny.  After adjusting each of my front brake shoes in as far as they would go, the right front brake drum will just barely go on, but will not revolve.  The left front brake drum will go on and turn, but with heavy shoe contact.  I have marked my drums and shoes as being LF or RF.  Should I tell the brake guy to take about .030 more off of each shoe?  I will ask him to measure the drums and give the specs.  I'm going tomorrow.  Marc.

[Plymouthy Adams]

10 hours ago, Dodgeb4ya said:

Another way of centering/fitting shoes to each drum after first making sure each shoe lining arc matches each brake drum.

This if you don't have shoe adjusting tooling..... ammco 1750 or Miller MT-19. Just another.old time way.

Feeler gauge is used at toe and heel of each brake shoe...

Cut a slot in each anchor bolt in line with anchor arrow...mark arrow at correct end of cut slot to match direction of factory arrow.

Use screw driver to rotate shoe anchor bolts and cams to center shoes to drum and set toe and heel clearance. Do not over loosen anchor nut. 

After adjustment pull drum to hold anchor bolt to tighten .nuts

Yellow front anchor bolt arrow is shown set to move brake shoe heel furthest from the drum....arrow is to be  pointed  thru centerline of front wheel cylinders.

This is also the original factory front anchor bolt setting.

Rear brake lower brake anchors should point at each other but just angled downward the slightest bit.

This setting pulls the rear brake shoe heels in from the drums the maximum amount.

This is also the original  factory rear anchor bolt setting.

Adjust to your liking.. your cam and anchors.

 

 

 

Thanks for posting the pictures Rob, this will show what I tried to explain above as written in the repair manual also...

[desoto1939]

On my 39 desoto the two eccentric pins have the arrows stapped into each one so you when the are pointing directly at eachuther they are then set back to the base adjustment.

 

Mine have the built in flat spots so that if I remember correctly either a 3/8 or larger box wrend with fit on each pin.

 

So after loosening the castle nut on the back of the backing plate you can then manually  rotate each eccentric pin so as to get the proper adjustment for each shoe..  After all adjustments have been completed then you need to use a toque wrench and set the ft lbs to between 55-70 Ft lbs to tighten the castle nut.  Hold the eccentric pin in position with your box wren and tighten the castle nut on the back of the backing plate.

 

Retest that the hoses have not moved out of adjustment.

 

 

Also in the instruction sheet that came from the Ammco brake safe arc instruction note that it also talks about the.030 automatic adjustemnt that is built into the tool.  I think this is for all of their mode but the document refered to so specific model that were referred to inthe instruction manual.

 

After reading the instruction I think the fixed anchor shoes do not need the various  anchor sdjusters becase these i think were used when doin  the Bendix type of brakes and not the Lockheed brakes.

 

Anyone have any input on this part of the discussion.

 

Rich Hartung

desoto1939@aol.com

[Dodgeb4ya]

I use the 8000 universal series ammco machines with out the built in toe heel clearance. No adjusting plates or bushings to deal with.

And I always go by eye for the toe/heel grind clearance. 

I want to grind shoe lining with just a tiny amount of clearance at the ends.

You learn what works for different type shoes/brake types over the years.

The 8000 is the later/last style arcing machine they made...epa rules shut it down.

Not that many here care as few have this equipment.

I used the Ammco ,Barrett and other brands...like the Ammco 8000 the best.

 

[MarcDeSoto]

Took my drums and shoes back to the shop today.  I asked him to mike the drums.  Turns out my drums were undersize by .020" and my shoes were oversize at 1/4" originally.  So I was facing a double whammy when I tried to put the front axle brakes together!    I haven't assembled them yet, but hoping this time will do the trick.  I don't want to have to drive back to Long Beach again where I'm surrounded by speeding 3 axle semis bumper to bumper!  

[Dodgeb4ya]

.250" linings are way too thick even with drums turned to twenty over.

3/16" = .180"....this is the maximum spec thickness of your linings.

Measure them accurately...I hope they ground them to that spec so you/we can be done with the drums fitting over the shoes problem.

Then back on to adjusting the shoes?

Edited April 30, 2023 by Dodgeb4ya
Tech data mistake

[MarcDeSoto]

Yes, I think I have enough for a book now.  Maybe it will become a best seller like Zen and the Art of Motorcycle Maintenance.

[desoto1939]

that is strange that your drums were undersized by .20. Most drums during their lifetime would have been cut at least one time, but being under seem odd to me but who knows what mother MoPar might have done over the years.

 

Keep us posted on how the shoes and drums go on the car.

 

Rich Hartung

[James_Douglas]

Marc,

 

To be clear, your 11 inch drums measured 10.80 inch ?

 

James

[MarcDeSoto]

Wait, I think I said they were .020 undersize, not .20" undersize.  I told the man my drums are supposed to be 11".  then he miked them and said they were .020 undersize.  .20" would be 1/5 of an inch, right?  No they are not 10.80"

[Dodgeb4ya]

At twenty undersize=.020" /turned .020" over

The drum will be @ 11.020"

Edited April 30, 2023 by Dodgeb4ya

[MarcDeSoto]

Oh.  I think he said the drums were .020 undersized, so Dodge must be right.  If the drums were exactly 11" and were turned by .020, they would be a greater diameter INSIDE DIAMETER and would need theoretically a thicker shoe lining.  So my drums might have been turned once in the past.  

[Dodgeb4ya]

11.020" is not much of a oversize drum....actually it's a .010" cut on the lathe. ..a quick clean up cut.

.060" is the maximum oversize on most drums.

[James_Douglas]

Ok,

 

So your drums are twenty thousands of and inch OVERSIZED as they are 11.020 inches. The maximum by the book says one can go to 11.060.

 

Now what I am going to say everyone will have to take with a grain of salt. Years ago I ran across a man who was an engineer at MOPAR who designed the brake systems back in the 1950's and 1960's. We talked about drums.

 

He said that the 0.060 max was one half of the "engineering tolerance" that they built in. The legal folks made them take the .120 and cut it in half. His take was that for a car that was used only on weekend and not driven hard he would feel fine driving on drums up to 0.100 inch over. For cars driven hard he would feel fine going to 0.080. 

 

Of course one should evaluate ones own risk on having a drum crack and take the above for what it is worth.

 

Now back to Marc's problem. My Wagner Brake Catalog showed linings as follows:

 

For Drums that measured standard size, in this case 11.000 one would order a 3/16 lining.

 

For Drums that were between zero 0.030 inch one would order the lining at 3/16 inch PLUS 0.015 or 0.2025 inch thick.

 

For Drums that were between 0.030 and 0.060 inch one would order the 3/16 inch plus 0.030 or 0.2175 inch thick.

 

Then one would arc the above shoe in a machine using the drum diameter and the 0.030 cam grind.

 

So as long as Marc's shoe lining is 0.2025 thick and they arc it with the .030 cam grind his shoes should fit.  If not, then either the drum is not round (offset turned), the pins are not right, the wheel cylinder distance from the mounting hole to the pin boss is longer than original or something is wrong with the minor adjuster.

 

James

 

PS. Remember that the machine performs a "cam grind" not a perfect circle less some amount like the drum. The machine's cam grind makes the ends of the shoes have a .008 inch clearance on the heels and toes of the shoe so someone does not have to do it with a file or a block of sandpaper. It is built into the "Cam Grind".

 

Edited March 1, 2022 by James_Douglas

[Crisjr14]

OK gentlemen I'm jumping in this on as I also am having trouble with my 53 dodge meadowbrook brakes long story short guy was supposed to fix my brakes but flaked on me I never watched how he took apart so I am in same situation as to trying to put everything back together so dodgeb4ya on your pictures that you posted can you be more specific and maybe show better pictures of where you made those slots to put the feeler gauge please so I've also heard that if the plates and spring that hold the shoes have to be turned a certain way as and also the anchor bolts with the arrows have to be facing a certain way well  so I went to have my drums cleaned and surfaced and the tech told me one of them is badly warp and bent any help from anyone would be greatly appreciated thank you 

[Sam Buchanan]

21 minutes ago, Crisjr14 said:

so I've also heard that if the plates and spring that hold the shoes have to be turned a certain way as and also the anchor bolts with the arrows have to be facing a certain way well 

 

 

The first step is to educate yourself on how these brakes assemble, adjust and function, otherwise you are lost. It looks like you either don't have a shop manual or haven't studied it. If you need a shop manual here is a link:

 

https://www.rockauto.com/en/moreinfo.php?pk=12781173&cc=1331727&pt=10335&jsn=494

 

While you are waiting on the manual to arrive, here is a tech article from the Tech section of our forum:

 

https://p15-d24.com/page/p15d24/tech/brakes.html/

 

One other little item......please punctuate your posts with some periods. 

 

Stick with it, once you understand these old brakes it is easier to maintain them.

[Bingster]

I have a '48 Desoto and am facing the very same brake problems. These brakes are notorious for being somewhat of a bear to adjust. I'm not looking forward to that. And I hear that the aren't as reliable as some.

 

But I must say. I always thought that converting to disc must be a very involved and expensive job till I saw somebody do it on a YouTube video. It seemed pretty straightforward with the kits you can buy. And discs are I guess the bees knees.

 

I still can't justify the cost of converting, especially as I have the shoes and such. But it's tempting. Of course, that blows the historically accurate brake system. 

[desoto1939]

2 hours ago, Crisjr14 said:

OK gentlemen I'm jumping in this on as I also am having trouble with my 53 dodge meadowbrook brakes long story short guy was supposed to fix my brakes but flaked on me I never watched how he took apart so I am in same situation as to trying to put everything back together so dodgeb4ya on your pictures that you posted can you be more specific and maybe show better pictures of where you made those slots to put the feeler gauge please so I've also heard that if the plates and spring that hold the shoes have to be turned a certain way as and also the anchor bolts with the arrows have to be facing a certain way well  so I went to have my drums cleaned and surfaced and the tech told me one of them is badly warp and bent any help from anyone would be greatly appreciated thank you 

You stated that the tech told you the drum is warped and bent. Did he show you the location of the two defects?

 

Also when and if you have your drums turned the mechanic should also be asking that you bring along either the lug nuts and or the lug bolts when they get ready to cut the drums.  The reason is that our drums and and the associated hubs are rivited to each other. To insure that you get a perfect cut there is no way that the mechanic can determine if there isa ny loosness in the two parts. If there isa ny loosness then this will cause the cutting of the drum to get some slight uneven cutting.  My mechanic did my 1939 Desoto drums and used my lug bolts all 5 of them to tighten down the drum and hub and then cut each front hub.  Also you will need to cut both either the front and or rears hubs as a pair to insure that they are not going to pull.

 

If you mechanic does not understand these basic principals then seek out another mechanic.

 

Here is another good story. A friend took his old car into his trusted mechanic to have a petronics ignition installed. They could not get the car to run smoothly. I spoke to the mechanic and asked what plugs they were using and he stated the regular plugs. I told him that they should be using the resistor plugs as per all of the reading that I did on the petronics system. The mechanic then stated what is a resistor plug.  I told my friend that he needs to go to another mechanic.

 

So ask a lot of questions when you are getting repairs done on your older cars.  The new guys only Know the new stuff but promise you they can fix everything.  Just making note of having knowledge is so important.

 

Rich Hartung

Desoto1939@aol.com

[keithb7]

Cris, did you watch the videos I made, that someone posted on your AACA post about your brakes?

 

You need a service manual to read and grasp the concepts. Then a tool to get them set up concentric, and right.  A You Tube search will all net you several brake related videos that I created and share there. 

Edited April 28, 2023 by keithb7

[Crisjr14]

Thanks all of you for your information 

[Crisjr14]

OK so when I was going to try everything to put everything back on and do the adjustments like you all said and going by all the links you all shared I noticed the spindle looks VERY VERY worn down like it was rubbing against something any suggestions before I try and put it back together please

[kencombs]

If you are speaking about the rough finish on the long taper, that is normal.   Many parts are left that way on non-contact surfaces in production