Drums lock up when I torque anchor bolt nuts on 48 Desoto

[MarcDeSoto]

I found out today that when I torque the anchor bolts to spec, then the brake drums tighten up so you can't even turn them.  I found that even if you just tighten the anchor nut a little bit it tightens up the drum.  Lockheed brakes have a deserved reputation for being difficult.  I think it's time to take it a brake expert like C. H. Topping for adjustment.  

Edited March 10, 2022 by MarcDeSoto

[James_Douglas]

This can only happen for two reasons that I am aware of:

 

1. The cam is turning when you tighten them.

 

2. The metal brake shoe is bent so that when you tighten the bolt it causes the main shoe spine to cock and one edge or the other of the friction material move out at an angle and meets the drum face and locks it.

 

James

[keithb7]

Look at little flat spot at the end of the bolt threads. Thread your nut past this. Grab your pliers or vice grips. Grab on this point to hold the bolt still. Then torque the nut down.

[harmony]

On my car the pivot bolt doesn't protrude past the nut except for one which has a castle nut on it for a cotter pin for some strange reason.  Even that one was too short to grab with vise grips. More about that one at the end of my spiel. 

 

So I put a wide slot in the end of the pivot bolt.  Then I made up a special tool from a small metric socket and welded a piece of angle steel on the end of it.  I used a quarter inch drive socket/ratchet because there just isn't enough room for a 3/8" socket/ratchet.  

Then I set the torque with my crowsfoot wrench while holding the pivot bolt from turning with the special tool.

 

So now, if the pivot bolt needs adjusting I slip on a offset 7/8" box end wrench on the nut first, then my special tool in the slot, then move the ratchet so it lines up with the wrench, then I move both at the same time in either direction.

 

Here's a strange footnote that you might encounter Marc. For the pivot bolts on the front brakes ( lower)  There is a castle nut. ( at least on my Chrysler) As you know the torque setting is 55-75 ft lb.  There are only 3 turrets on these nuts. So on my car that full range of torque setting ends up with the hole for the cotter pin right in line with one of the turrets.  So I dug through my stash of washers and I was fortunate enough to find a pair of washers the right size that were very thin.  They were just right to get the torque at 55 and have the hole accessible for the cotter pin. 

[MarcDeSoto]

Keith has 1938 MoPars and a 53 Chrysler which I think he sold.  Maybe those anchor bolts are different on out postwar cars?   Harmony, that's an ingenious device!  I was thinking.  Wouldn't it be easier to just do the brake adjustment with the drum off.  The torque the nuts before mounting the drums, making sure you don't turn the anchor bolt cams?  Or is doing the torque job before mounting the drums not possible?  

[keithb7]

My ‘38 is seen here. I’m not convinced they improved upon this later. As seem in Harmony’s photos. 
 

 

 

Edited March 11, 2022 by keithb7

[MarcDeSoto]

That design looks far superior!  Harmony had to do a lot of work to get something that worked.  

[kencombs]

6 minutes ago, MarcDeSoto said:

That design looks far superior!  Harmony had to do a lot of work to get something that worked.  

Cutting the slot is a great idea.  However, it is not necessary to create a custom tool.  Socket bits in many screwdriver sizes are readily available for many tool vendors.

[harmony]

49 minutes ago, MarcDeSoto said:

Keith has 1938 MoPars and a 53 Chrysler which I think he sold.  Maybe those anchor bolts are different on out postwar cars?   Harmony, that's an ingenious device!  I was thinking.  Wouldn't it be easier to just do the brake adjustment with the drum off.  The torque the nuts before mounting the drums, making sure you don't turn the anchor bolt cams?  Or is doing the torque job before mounting the drums not possible?  

You're quite right Marc.  I got them as close as possible before sliding on the drum.  But to be sure I didn't torque them.  Then I discovered that I could still make the heel of the shoe a little tighter.  I was trying for around 9 th.  

In the end I got them almost to the torque setting, Then once the drum was on I went ever so slightly more.  Then torqued them to 55 ft. lbs once the drum was on using the method I mentioned earlier. A lot of screwing around. 

I really dislike this style of brake shoe adjustment of these years.  

[harmony]

38 minutes ago, kencombs said:

Cutting the slot is a great idea.  However, it is not necessary to create a custom tool.  Socket bits in many screwdriver sizes are readily available for many tool vendors.

Trust me you need a huge amount of effort to hold that tool in place while trying to get 55 ft lbs applied.  The issue is you are not applying pressure straight on.  So the tool keeps trying to jump out.  I'm not sure if I took a picture of the tool the first time I built it, but the force of 55 ft lbs on the piece of steel on that custom tool I made actually tore the end 50 % right off.  So I had to mig weld it back on.  You can see the extra mig welding done on the tool.  At first I thought I'd try one of those right angle slot screw drivers.  No way I could keep it in the slot.  At least with the ratchet, I could sort of get my fingers close to the end and push hard, while working the torque wrench with the other hand.

The other problem is that the slot needs to be quite wide or any tool will just twist.  I used bed frame material.  You know those "budget" bed frame that hold a box frame mattress.  Basically 4 pieces of angle steel  bolted together.  I think it's about 1/8" thick.  That stuff comes in handy for all kinds of tools and jigs.  Most people throw them out so they are constantly on the side of the road with a free sign on them.

If I was ever to build the tool again for another car, I'd go with even a wider slot. For more strength

As Keith mentioned, his earlier pivot pins are far superior. 

Edited March 11, 2022 by harmony

[harmony]

There was one pivot bolt where there wasn't enough room for the head of my torque wrench and the head of the 1/4" drive ratchet.  Since they are so close together.  So I had to build another tool that took up less room.  But this tool doesn't have the option of adjusting the handle to line up with the box end wrench later on for adjusting both nut and pivot pin at the same time.

In this case since the tool was a little flimsy and lacked weight.  I had to wedge a block of wood from the back side of it to the king pin I think, I can't remember right now.

I used one of those adapters to go from a 1/4" hex - 1/4" socket recess.  Then I JB welded on a 1/4" box end wrench.  Then I cut off the excess.  Then I got a thin piece of oak and made a wedge out of it to apply pressure ( between back side of tool and king pin)on the tool to keep it from jumping out of the slot.  

Edited March 11, 2022 by harmony

[harmony]

1 hour ago, keithb7 said:

My ‘38 is seen here. I’m not convinced they improved upon this later. As seem in Harmony’s photos. 
 

 

 

The other thing I'm noticing ( besides the superior pin design) is the number of turrets as opposed to my '48 castle nut.  As I mentioned there are only 3 turrets on my nuts, So once you get the cotter pin in, in theory the nut can loosen almost an eighth of a turn.  I'll see if I can find a good picture of the nut.

[harmony]

I found a picture of what I've been talking about with my castle nut only having 3 turrets.  You can see just how much movement the nut could have before the cotter pin stopped it.

[harmony]

Just now, harmony said:

I found a picture of what I've been talking about with my castle nut only having 3 turrets.  You can see just how much movement the nut could have before the cotter pin stopped it.

Yes, I know in the picture, the torque wrench is not at 90 degrees to the crowsfoot.  This picture was taken just to document the procedure and then after the picture,  I ratcheted it up to 90 degrees before I applied the torque.  At this point I think I was using my knee to hold the torque wrench.  While I shot the picture.

[MarcDeSoto]

Tomorrow, I'm going to try to adjust the shoes and then torque the anchor bolt nuts with the drums off, so I can hold the nut from rotating with a wrench.  Do you think that is a better way to do it?  

[Doug&Deb]

I believe you’re supposed to torque everything down with the drum off. If you have the correct adjustment tool it’s easy. Otherwise it’s hit or miss. The good news is once you get everything adjusted properly they’re good brakes and easy to maintain.

[Sniper]

4 hours ago, MarcDeSoto said:

Tomorrow, I'm going to try to adjust the shoes and then torque the anchor bolt nuts with the drums off, so I can hold the nut from rotating with a wrench.  Do you think that is a better way to do it?  

 

 

That is how you are supposed to do it.

 

You've spent more time here trying to get advice on how to undo the goat rope you've created than you would have spent had you just followed the manual  Get the manual read it, follow it, ask questions if the manual is unclear.  Don't wing it, don't think you know better.  I don't mind helping someone out but geez, you've shot yourself in the foot so many time by winging it that Long John Silver is thinking about loaning you his spare peg leg.

 

you had best find a deserted place with plenty of coasting room to come to a halt when you test these brakes.

[kencombs]

7 hours ago, harmony said:

Trust me you need a huge amount of effort to hold that tool in place while trying to get 55 ft lbs applied.  The issue is you are not applying pressure straight on.  So the tool keeps trying to jump out.  I'm not sure if I took a picture of the tool the first time I built it, but the force of 55 ft lbs on the piece of steel on that custom tool I made actually tore the end 50 % right off.  So I had to mig weld it back on.  You can see the extra mig welding done on the tool.  At first I thought I'd try one of those right angle slot screw drivers.  No way I could keep it in the slot.  At least with the ratchet, I could sort of get my fingers close to the end and push hard, while working the torque wrench with the other hand.

The other problem is that the slot needs to be quite wide or any tool will just twist.  I used bed frame material.  You know those "budget" bed frame that hold a box frame mattress.  Basically 4 pieces of angle steel  bolted together.  I think it's about 1/8" thick.  That stuff comes in handy for all kinds of tools and jigs.  Most people throw them out so they are constantly on the side of the road with a free sign on them.

If I was ever to build the tool again for another car, I'd go with even a wider slot. For more strength

As Keith mentioned, his earlier pivot pins are far superior. 

I understand the need for a good fit in the slot and a nice square engagement.  I'd cut the slot with  an .040 cutoff wheel and multiple passes if needed so it would fit a bit made of tool steel.  Then use a tool similar to this:

Just to avoid spending time toolmaking and not working on the car/truck.

edit to add:  I've used similar tools to remove and install slotted guide studs for heads and transmissions for years.  Somewhere I have the huge version used to adjust the old style, spring loaded drag link ends use on a lot of trucks in the 40s/50s.   That would be a good start to make a custom sized, heavy duty driver.

Edited March 11, 2022 by kencombs

[harmony]

1 hour ago, kencombs said:

I understand the need for a good fit in the slot and a nice square engagement.  I'd cut the slot with  an .040 cutoff wheel and multiple passes if needed so it would fit a bit made of tool steel.  Then use a tool similar to this:

Just to avoid spending time toolmaking and not working on the car/truck.

edit to add:  I've used similar tools to remove and install slotted guide studs for heads and transmissions for years.  Somewhere I have the huge version used to adjust the old style, spring loaded drag link ends use on a lot of trucks in the 40s/50s.   That would be a good start to make a custom sized, heavy duty driver.

If my shop was right next door to a major tool supplier, I would still spend an hour or two building a custom tool for a particular job, even if I only used it once.  It's who I am, it's what I love to do.  My father was a very successful inventor and made many of the thing that people still use every day.  It's in my blood.  If I finish the day without grease under my fingernails, or my coveralls aren't dirty, I feel that something went wrong, I feel like I have let myself down. 

 

As for the snap on tool you suggested.  I have the same bit in my hand held impact tool.  The blade isn't nearly wide enough.  Plus the one point I was making was the tool needs to be very compact. even by using 1/4" drive for one pivot pin it was too long ( distance out past the end of the slot I made)  which is why I made the more compact version.

8 hours ago, harmony said:

I found a picture of what I've been talking about with my castle nut only having 3 turrets.  You can see just how much movement the nut could have before the cotter pin stopped it.

Yes, I know in the picture, the torque wrench is not at 90 degrees to the crowsfoot.  This picture was taken just to document the procedure and then after the picture,  I ratcheted it up to 90 degrees before I applied the torque.  At this point I think I was using my knee to hold the torque wrench.  While I shot the picture.

[harmony]

Many times I have been puzzled with a particular task at hand and pulled out the service manual, and after reading what is there in print, I'm still not informed.  I believe the manual is made for the Chrysler Mechanics as an assistant or reference to go to after the schooling that they have already had that makes them a certified mechanic.  There has been countless times that I couldn't even find anything in the manual at all, that was in reference to what repairs I was making on the car.   The tech tips videos and literature supplied by imperial are a lot more informative.  

 

I personally think that if someone has a question about anything, no matter how simple or complicated the solution might seem to me, I have no problem offering my suggestions or any past experience I might have with the same issue.  If weeks later someone else has the same issue, I have absolutely no problem repeating myself. 

 

Sometimes the more an issue or problem is discussed, often a solution is found by coming at it in a different way or sometimes a particular persons explanation just hits home.  

 

As a well known person named Confucius once said.  The only stupid question is the one not asked

Edited March 11, 2022 by harmony

[harmony]

8 hours ago, MarcDeSoto said:

Tomorrow, I'm going to try to adjust the shoes and then torque the anchor bolt nuts with the drums off, so I can hold the nut from rotating with a wrench.  Do you think that is a better way to do it?  

I'd go that route too.  Try to get the clearance as tight as possible without the drum dragging as you slip it on and give it a spin.  

Edited March 11, 2022 by harmony

[desoto1939]

Marc: Yes get the shoes and drums setup so that they are at the proper distance from each side of the drum. The eccentrics should have a flat spot so that a 3/8 or 9/16 box end wrench can hold the eccentric from pivoting. So put the wrench on the eccentric and then use your torque wrench set at 50-55 ft lbs and then tighen the castle nut fromthe back of the brake backing plate.  Then installthe cotter pin.

 

Rich Hartung

Desoto1939@aol.com

[MarcDeSoto]

To Sniper: You sound like you are the one who doesn't read the shop manual.  If you had read it, you would know it doesn't answer my questions. I always have the shop manual and the Parts Book at my elbow when I am doing this work.    All the shop manual gives you is the torque spec, not when to do it.  The only reason I have all of these questions is when I follow what little direction there is in the manual, it doesn't work.  So I have to do all of these things to find some way to get it to work.  Look at all the work Harmony had to do to torque his anchor bolt nuts.  That's not in the shop manual.  So just following the shop manual is not the answer.  

 

To desoto 1939:  I think the pre-war brakes are a little different than the post war.  My anchor bolts don't have that notch that sticks out beyond the nut so you can stop the anchor bolt from turning.  So I will the hold the anchor bolts from the front with a wrench with the drum off, and torque the nuts to 55 ft. lbs., then install the drums.  If there is a better way, tell me.  And don't say read the shop manual.  Been there, done that.  

 

[desoto1939]

Marc. Exactly use you boxend wrench to hold the eccentric in place witht he drum off. Then use your torque wrench set at 55 ft lbs to tight eccentric castle nut but useing the box wrench the eccentric will not move.

 

You are understanding what to do. Let us all know how this works out for you. Yes the service manual does not go into great details becsue it was understood that as a mechanic you had some expereience or could work with a senior service person in the Desoto dealership.

 

Keep asking questions this is how everyone learns how to keep these old cars running. Watch the video from the service tech tip that was posted and you will see how they hold the eccentric and then use the torque wrench on the castle nut.

 

Rich hartung

Desoto1939@aol.com

[MarcDeSoto]

Just did my rear drums this way by holding the anchor bolt from the front with a box wrench and torquing the nut to spec from behind.  Worked like a charm.  The drum went on easily.  Don't know if it will be that easy on the front brakes, but I hope so.  Thanks for everybody's input on this.  Marc.