Tight Drums on 38 front end

Scott H

Scott H

Well-known member
Rebuilding the brakes on my 38 car front end. Original mechanical cable-operated brakes.
Putting the drums back on they fit nice and smooth and I can easily spin them around, right up until the point I try to snug down the spindle nut. If I tighten it the drum locks up. If its only finger-tight I can spin the drum with slight drag.

Its the same drum, the same inner and outer bearings.
Everything is squeeky clean and no rust.
Fresh grease with new Chicago Rawhide Grease Seal # 15730.
Even the shoes are original with NOS Ford linings arced to the shoe.
Again, no brake drag, but the it seems to bind up when I snug the spindle nut.
Just to eliminate the grease seal as being the culprit (its the only part that is changed from original) I swapped on the drum from the other side WITHOUT installing the grease seal. Same result.

Is this just the way these things are? I'm accustomed to newer (1960's) cars where you snug down the spindle bolt and then back off slightly and the drum spins freely if your brakes aren't dragging.
 
Had a bent brake shoe at pivot that caused the same problem for me on my 39 pickup during reassembly of brake system.Took me a lot of head scratching to figure out that shoe was hitting side of drum when tightening up.Once I straightened it out the problem was gone,just a thought.
 
GaryU. said:
Had a bent brake shoe at pivot that caused the same problem for me on my 39 pickup during reassembly of brake system.Took me a lot of head scratching to figure out that shoe was hitting side of drum when tightening up.Once I straightened it out the problem was gone,just a thought.
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Thanks..I don't see any shiney spots inside the drum where the shoe would be contacting. I'll try chalk on the shoe and I'll put a straighedge across it. They are the same shoes I took off, just relined.
 
I think you will find the ends of shoes are hitting.This is what is done about that.Grind the ends of shoes back 1/8 depth back 1/2inch.This will make sure the middle of shoe hits,and when tighting the nut the shoes won,t move.
 
I don't know if you have the same excentrics as a 39 or not. I just went through a bout with a new set of lineings. I would sand the high spots off the lineings, adjust the bracks and go for a ride. After a while when I came to a stop it would coast cost down slow and stop, on a hill it would stay in place and not roll. Back to the shop and the wheels were hard to turn. Adjust go for a ride and the same thing, did this about 6 times. Took the lineings off and dicovered that the ends of the metal shoes where the large hole for the excentrics are the metal was thicker than the excentric brass washer causeing the shoes to bind. These were the after market ones that you can see the projection welds holding the flat part to the curved shoe part. The ends where the excentric is on the ford shoes was machined to a thickness less than the brass spacer. The after market shoes were thicker than the brass washer causeing the binding. G.M.
 
G.M. said:
I don't know if you have the same excentrics as a 39 or not. I just went through a bout with a new set of lineings. I would sand the high spots off the lineings, adjust the bracks and go for a ride. After a while when I came to a stop it would coast cost down slow and stop, on a hill it would stay in place and not roll. Back to the shop and the wheels were hard to turn. Adjust go for a ride and the same thing, did this about 6 times. Took the lineings off and dicovered that the ends of the metal shoes where the large hole for the excentrics are the metal was thicker than the excentric brass washer causeing the shoes to bind. These were the after market ones that you can see the projection welds holding the flat part to the curved shoe part. The ends where the excentric is on the ford shoes was machined to a thickness less than the brass spacer. The after market shoes were thicker than the brass washer causeing the binding. G.M.
Click to expand...

Interesting the things we discover on these old cars. Thanks for sharing. My shoes have Ford script on them as well as a stamping "P" for primary and "S" for secondary
 
George/Maine said:
I think you will find the ends of shoes are hitting.This is what is done about that.Grind the ends of shoes back 1/8 depth back 1/2inch.This will make sure the middle of shoe hits,and when tighting the nut the shoes won,t move.
Click to expand...

Thanks for the idea, but as these are NOS Ford linings, in the Ford box with Ford script on them, they are pre-chamfered on the ends. They come with the ends already tapered.
 
Scott H said:
Rebuilding the brakes on my 38 car front end. Original mechanical cable-operated brakes.
Putting the drums back on they fit nice and smooth and I can easily spin them around, right up until the point I try to snug down the spindle nut. If I tighten it the drum locks up. If its only finger-tight I can spin the drum with slight drag.

Its the same drum, the same inner and outer bearings.
Everything is squeeky clean and no rust.
Fresh grease with new Chicago Rawhide Grease Seal # 15730.
Even the shoes are original with NOS Ford linings arced to the shoe.
Again, no brake drag, but the it seems to bind up when I snug the spindle nut.
Just to eliminate the grease seal as being the culprit (its the only part that is changed from original) I swapped on the drum from the other side WITHOUT installing the grease seal. Same result.

Is this just the way these things are? I'm accustomed to newer (1960's) cars where you snug down the spindle bolt and then back off slightly and the drum spins freely if your brakes aren't dragging.
Click to expand...

Did you mean "arced to the drum"
The chalk should show where it is tight.
Bruce
 
cmbrucew said:
Did you mean "arced to the drum"
The chalk should show where it is tight.
Bruce
Click to expand...

No, I meant they are pre-arched to fit the shoe nicely. I had a service do the riviting instead of me buying the tool. He said they would fit nicer on the shoe than the bulk material they usually use.

Yeah, still gotta get back out there and try the chalk. The puzzeling part for me is that at 90% installed the drum spins freely. If the shoes were binding I would think they would be binding as soon as I slip the drum on, not only when spindle the nut is tightened that final turn.

Maybe I don't really have a problem. Ford Service Manual says to install the nut finger-tight and then back off 1/6th turn (max) to line up with the cotter pin hole.
 
I think you should tighten with wrench to make sure all is tight then back off. This is what I found out you may want to check.
Insert adjusting wedge with arrow poining to front of car.
Put brake shoe in place so that tapered ends fits into slots of adjusting wedge.
Hope this helps.
 
You may have an issue with the wheel bearing spacing only. The shoes usually have a fair little bit to move around in there so it shouldn't be making contact with the edges of the shoes. If the seal was somewhat out of position, it could be bottoming on the spindle. You could try one drum with the shoes removed and see if the problem persists. That would at least eliminate the shoes.

Timkin tapered rollers need a bit of preload to function correctly. Normally, when rou tighten the nut snug, you just get more drag. You usually have to tighten it a good bit more to get it to lock up so it's likely bottoming out on something. Nut should go up snug then back off to the nearest castelation. There should be no noticeable shake or teeter in the wheel bearings.

Kerby
 
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Thanks Kerby!
I'm closing in on this. I haven't tried the chalk yet. I moved over to the driver's side and put the drum on the spindle with NO backing plate (with fully greased bearings and a new seal) to see how that side works. Tightened down the spindle nut and I could still spin the drum no problem. Nice and smooth.

So back to the passenger side to eliminate potential sources of drag one at a time. First I'll try the chalk to see if there are any witness marks of interference. Then I'll remove the shoes and try the drum again. If need be I'll even take off the backing plate and start from scratch.
 
1931 flamingo said:
Try swapping the drums. Put the one you said turns on the side that won't and vice-versa.
Paul in CT
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Thank you Paul. Tried that and it acts the same with the other drum.

I played around with the Anchor Pin and the Adjusting Screw and got it to free up enough that it seems normal. Very slight drag. I thought I had the Adjusting Screw backed out all the way but I was able to go a bit further, I was just getting worried with the amount of pressure I had to use on the last couple turns.

After going thru this on the one side it should make the opposite side go together like butter!
 
Take a look and see if there is a tapered end on one of the shoes.
One must be different from other.Now if the lining are same lenght did they get mixed up on riviting.Pri maybe on wrong shoe.That will miss you up.
 
George/Maine said:
Take a look and see if there is a tapered end on one of the shoes.
One must be different from other.Now if the lining are same lenght did they get mixed up on riviting.Pri maybe on wrong shoe.That will miss you up.
Click to expand...

Thanks for the tips George. Linings are all the same length, both now and before they were changed. I think they may have been original linings as the car only had about 40k miles. All the lining ends came out of the factory box pre-tapered.
 
I'm not familiar with how the shoes are centred on that year, but I had a problem with one of my '32 rear brakes whereby wear on one of the guides was allowing the shoes to sit out of line (eccentric to the axle). I just had to build up the worn part with a little weld to correct the problem.
 
I'm not sure as to what i'm saying.
If you are going by what the shoes have writen on them you may have a problem.Say the guy puts the wrong pri on wrong shoe.
Also if the lining hit they will be up top.
Some times they are tapered back to just before first rivet
 
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