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

[MarcDeSoto]

I ground down my push rods with a bastard file in the middle of the fork, but still can't get the  drums back on.  So I guess I'll try sanding the shoes down.  I don't know if they are asbestos or other material, so I will put on a painter's mask and gloves to avoid breathing in the asbestos.  Should I use a block sander or use a jitterbug?  

[James_Douglas]

Marc, Something does not sound right. Can you post a set of detailed photos of:

 

1. One of the shoes.
2. The wheel cylinders.

3. The anchor bolts.

4. The adjuster cam.

 

You really cannot had sand the shoes and get them correct. You will just make a mess. Call around and see if anyone has and will arc the shoes for you. If not, then try calling Moose Motors Obsolete Brake Parts at 707-792-9985. Jeff, if he is still in business, can sell you a set that he will arc for the drum size you give him.

 

James

[MarcDeSoto]

Most brake shops that I called said "What is arcing the shoes?".  Others said "Oh, that hasn't been done since the 80s".  I'll take some pics.  Why do so many say to sand the shoes down?  

[Dodgeb4ya]

I thought Jeff didn't like teaching new customers how to do brake work or even accepting Diy'ers.?

 

[MarcDeSoto]

[MarcDeSoto]

[MarcDeSoto]

[joecoozie]

Don't know if this has been mentioned but the arrows on the anchor bolts should face towards the wheel cylinders when assembled.

[harmony]

Have you given any thought to having weak return springs?  I'm not sure if there is a way to test them unless you have a new one to compare it to. I think you said earlier that you don't have any fluid in the lines and cylinders, right?  So when you have everything assembled and you're about to put the drum on, is the end of the shoe closest to the wheel cylinder right up against the rubber boot, and the piston is pretty much all hidden?

If the return springs are healthy, they should pull the shoes in pretty tight against the boot if there is no fluid in the cylinder.

[MarcDeSoto]

Good suggestion.  They are the old springs, so you might have a point there.  I still need to use brake spring pliers to put them on and take them off.  

I think Moose Motors is permanently closed now.  Not sure of this, but saw it online listed as closed.  

Yes, I know about the arrows on the anchor bolts facing the wheel cylinders.  One thing I wonder about though is if the anchor bolts are meant to turn to adjust them, but you have to point them to the cylinder, then how can you adjust them?  

Edited February 22, 2022 by MarcDeSoto

[Wes Flippen]

If you end up needing to sand them yourself, I sanded on a bench sander using 100 grit until the drum would just slide on. After that, I used double sided tape and taped 100 grit sandpaper to the inside of the drum and rotated the drum on the brake shoe to match the arc to the drum. May not be the best way to do it, but it worked for me. 

[61spit]

I believe you only start with the anchor bolt arrows pointed to the wheel cylinder. You do turn them to adjust but they are at the lowest point when pointed to the wheel cylinder - the starting point. Seems that if you measured the inside of the brake drum with the MT-19 tool and adjusted the tool to that diameter and then adjusted the brake shoes with the tool there isn't any way the shoes are set too large to get the drum on. Something must have moved/slipped after you set the tool to adjust the brake shoes and they ended up being set too far out.

[Kilgore47]

I used the attached procedure to adjust the brakes on the P15.  It works and I didn't have to track down all the special tools.  Also used the sand paper on the inside of the drum method to arc the shoes to the drums.  Only I found a roll of two inch wide sand paper with an adhesive back.  

Don't get me wrong - I believe in having the right tool to do the job.  But sometimes the right tool can be a different way to do it.

Brake Adjustment.pdf

[harmony]

As you have probably noticed MarcDeSoto, the last photo in the pdf that Kilgore47 added, it indicates that the two nuts/studs on the bottom are for the major adjustment.  When actually it's only the longest one that you adjust on your car.

Yes It sounds like a good idea to put a slot in the end of the major anchor bolt so you can adjust it from the back with the drum still on.  But in reality it's almost a waist of time.  The nut has to be tightened to 55-75 ft. lbs.  There is no way in the world that you can turn that adjuster with just a screwdriver.  Actually on all the adjusters you can't even get a screwdriver in the slot that you would have to cut into the end of the threaded stud.  Make the slot wide and deep.  I think the slot I made was about 1/8" to match the piece of flat stock steel that I had.  So you have to make a special tool for that.  I welded a piece of flat steel to the end of a socket.  But there is only enough room for a small shortened 1/4" drive socket and a 1/4" drive ratchet on some of them.  Then it's still impossible to get enough arm strength on the ratchet to move that adjuster.  Plus you can't put any pressure on the end to keep the tool from slipping out.  I made the slot about 3/16" deep.  Perhaps if I made it 1/4" deep or deeper I would have had better luck.  At one point I used a pry bar wedged in between the tool and the control arm.  In that case I actually twisted the flat stock that I welded on the socket and it actually tore the steel part way off.  So I welded it some more.  So you need an offset box end wrench over the 7/8" nut first.  Then put the home made tool in the slot. Then try to turn them both at the same time, just a tiny bit.  (perhaps it's easier if you have the car up on a hoist and you're not crawling around on the floor trying to position both arms just so, followed by grunts and groans and scraped knuckles) Which is way harder than you think since you probably only want to adjust it a smidge.  It's actually easier and faster to pull the drum off, loosen the nut, make the adjustment, then torque it down again.  I even tried to turn the head of the adjuster with a long 9/16" open end wrench, without loosening the nut on the back ( once I had the drum off).  It's pretty much impossible when that nut is torqued to even 55 ft. lbs. let alone 75 ft. lbs. Keeping in mind that you're only wanting it to turn ever so little. 

I know, getting ahead of ourselves here, but it will be something you'll be scratching your head over down the road, once you actually get the drums on.  I can add pics of the tools that I made if you want later on. 

Edited February 22, 2022 by harmony

[harmony]

1 hour ago, Kilgore47 said:

I used the attached procedure to adjust the brakes on the P15.  It works and I didn't have to track down all the special tools.  Also used the sand paper on the inside of the drum method to arc the shoes to the drums.  Only I found a roll of two inch wide sand paper with an adhesive back.  

Don't get me wrong - I believe in having the right tool to do the job.  But sometimes the right tool can be a different way to do it.

Brake Adjustment.pdf 461.48 kB · 2 downloads

What grit sandpaper did you find to be the most useful?  I'd also recommend running squiggly pencil marks all over the lining so you can see the high and low spots, if you use this method.

[keithb7]

Half way up the shoe, is the toe adjuster cam. Used for the "minor adjustment". Adjusting it moves the upper half of the shoes in our out. With the shoes and return springs properly installed go to the rear of the backing plate. Get a wrench and turn the quite large bolt head (1 1/16" wrench) towards the center of the spindle. This will turn the cam inward, allowing the shoes to retract in, toward the brake cylinders.  Turning it out forces the shoes out toward the drum.  Both the shoes have their own minor cam adjustment.  Each one turning the bolt head in opposite directions for adjustment. Start there at the minor adjustment.  Then head down to the two eccentric shoulder bolts at the bottom on the shoes. Turn the arrows pointed toward the cylinder as mentioned. With the shoes on, try twisting these lower bolts, and observe shoe movement. This is the heel of the shoe. Move the bolts so the shoes are in as close as possible to the spindle centre.  Now with the major and minor cams all the way in, the shoes and springs in place, try sliding your drums on. 

 

You aren't done yet, but the drum should at least side over the shoes. Next you proceed to set up the shoes concentric. This is where the fancy tool comes in to use. 

 

You can see a quick minor adjustment here:

 

 

Edited February 22, 2022 by keithb7

[keithb7]

Lots of good info here: 

 

[MarcDeSoto]

I have a 48 DeSoto, so my anchor bolts are not both at the bottom.  I've already done my rear axle, so on my post war car, I have two wheel cylinders in each brake drum.  I saw a good video on how to arc your own brake shoes.  My shoes perfectly fit the drum, so I don't really need to arc them, but I think I do need to take some lining off.  I'm planning on buying a HF 4" belt sander to do that.  

 

 

[desoto1939]

Marc Prior to sanding away any of the lining please take a measurement of just the thickness of the lining. Do not include the metal backing.

 

According to al of my Brake catalogs the thickness of the lining is 3/16 If is bigger than this thicknee then the put on the wrong brake lining.

 

Were these same linings that you are showing were they ever on the car or are they old shoes with linings that you had in your stock pile

 

from your above picture they seem to be thicker than 3/16.

 

Rich Hartung

[harmony]

2 hours ago, MarcDeSoto said:

I have a 48 DeSoto, so my anchor bolts are not both at the bottom.  I've already done my rear axle, so on my post war car, I have two wheel cylinders in each brake drum.  I saw a good video on how to arc your own brake shoes.  My shoes perfectly fit the drum, so I don't really need to arc them, but I think I do need to take some lining off.  I'm planning on buying a HF 4" belt sander to do that.  

 

 

Personally I prefer kilgore47's suggestion of using peel and stick sandpaper.  It's almost impossible to screw it up that way.  Just keep your air compressor handy to blow off the shoe/sandpaper regularly.  I wouldn't start of with like 24 grit because it's

 

2 hours ago, desoto1939 said:

Marc Prior to sanding away any of the lining please take a measurement of just the thickness of the lining. Do not include the metal backing.

 

According to al of my Brake catalogs the thickness of the lining is 3/16 If is bigger than this thicknee then the put on the wrong brake lining.

 

Were these same linings that you are showing were they ever on the car or are they old shoes with linings that you had in your stock pile

 

from your above picture they seem to be thicker than 3/16.

 

Rich Hartung

Is 3/16"specific to Desoto, or all Chrysler cars with 11" drums of that vintage?

[harmony]

At the end of the Master Tech video that Keith added, It talks about diagonal grooves in bonded linings.  However then they go on to put longitudinal grooves in the bonded lining.  I thought that was kinda confusing.

Anyways my bonded linings don't have any groves in them at all.  I'm guessing that they are about 50% worn.  I'm curious if anyone thinks I should add groves at this point?  I noticed that Marc's linings have offset diagonal groves.  They look pretty wide and pretty deep.  I'm guessing groves are there to get rid of the lining particles as they wear down.  

I would think that diagonal grooves would be more efficient than one longitudinal groove.

[MarcDeSoto]

I think 3/16" is right.  My 1948 shop manual says the lining is 13/64".  3/16" is 12/64" so close enough.  My linings measure about 1/4" which comes out to 16/64" which makes them a bit too thick.  Yes, these shoes have not been on the car before and have been just sitting on a shelf for all these years.  As far as the stick sand paper to the drums method, if I can't get the drums on without sandpaper, how am I going to get the drums on with sandpaper?

Edited February 23, 2022 by MarcDeSoto

[desoto1939]

So if the lining is close to a 1/4 on each shoe then you are now over by 1/8 inch in shoes thickness when both shoes are on the backing playe. So I think this is your problem. The lining is too thick and the drum can not clear the shoes.

 

Rich Hartung

[harmony]

1 hour ago, MarcDeSoto said:

I think 3/16" is right.  My 1948 shop manual says the lining is 13/64".  3/16" is 12/64" so close enough.  My linings measure about 1/4" which comes out to 16/64" which makes them a bit too thick.  Yes, these shoes have not been on the car before and have been just sitting on a shelf for all these years.  As far as the stick sand paper to the drums method, if I can't get the drums on without sandpaper, how am I going to get the drums on with sandpaper?

As for using sandpaper, do the job unassembled.  Put the drum on the bench or better yet rig up something so it stands upright.  Maybe a piece of 3/4" plywood, with holes drilled in it to match the bolt pattern, then bolt on the drum and then put the plywood in a vise.  Something like that.  Then after cleaning the inside of the drum with brake cleaner stick the sandpaper to the area where the shoes ride.  Then manually set the shoe in the drum and rock it back and forth like around 180 degrees or so.  Just keep checking it and marking it with a pencil.  Then when you get close to the right thickness, grab the next shoe.  If it's possible do it outside with a mask on since you're not sure if its asbestos or not.

[joecoozie]

On 2/18/2022 at 10:37 PM, joecoozie said:

Are the shoes new?

If so, the lining may be a little too thick and not allow the drums to slide on.

I have had this happen to me several times and I just had a very, very small amount of the lining skimmed off and the drums went on - no problem.

You may even try to skim off some of the lining yourself. I have done it using emery cloth working evenly along the shoe.

 

All good suggestions here BUT why don't you just grind/sand some of the lining off and that may be the "simple" solution to your problem.

If not then approach it from a different angle. But from your own measurements it looks like the shoe lining is too thick.