Front Drum Brake Issues

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firechicken1992

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Doing what I thought would be a routine drum and shoe replacement on my girlfriends 64 Valiant. Got the springs and everything apart (using proper tools as well). Put on the new shoes with primary shoe facing forward on both. Greased the new bearings and drove in the new races (again with a proper tool). Greased the star adjuster threads and cable. Put the hubs on and tightened down the wheels. Both sides seems to catch only at one point on the drum. My friend who worked at Orielly's (where i bought the parts) said he has sen warped drums outta the box before. I took them in to get checked and sure enough they were warped. Got them turned and brought them back home. Still catching! I have checked and rechecked multiple times and I'm at a loss. Ive had much more experience with disc brakes over drums although i have still done drum work, and never have had this problem. Any suggestions out there? Its been 100 degrees the past couple days and I've been putting hours into this each day and I'm about to lose it :banghead:.
 
Did you clean the hub mating surface ?

It can have dirt/rust accumulations, and/or burrs, try and run a flat file around the surface..

When you say "catching",, are you refering to driving and applying brakes and it pulls or grabs in some manner??

Or do you mean you spin it by hand, and feel the drum rubbing on one side ?? ( which is not unusual )
 
Please define the problem more specifically. I've seen LOTS of drums where they would "rub" the shoes in one place in wheel rotation, and still worked just fine.

The way I adjust shoes is to adjust them up tight, until you cannot turn the tire. Then back off until the drum rubs somewhat when rotated. This is a judgement call, and you "try" and get both sides about the same.
 
ok this all helps alot. im used to the ease of discs. it is rubbing, i guess ill try and take it around the block and see after adjusting the star wheel.
 
Actually i just thought about it. one side the star adjuster was all the way retracted and itd rub. the other side wouldnt rub until i adjusted it outward a little bit, thats where im at a loss
 
You still haven't saod what rubs what and at what location.
All I know at this point is you have added grease where there isn't supposed to be any. The only places where any type of lubricant is applied is the small rub pads stamped in the backing plate and inside the free rotating cap of the adjuster.
Grease anywhere else in there will collect brake lining material which could create a problem.
This is just a wild guess but if the outer edge of the linings is rubbing at the bottom of the drum, this is somewhat typical of aftermarket drums and linings.
Actually , Its common for the backing plate of a disc brake linings to need a bit of file fitting also, less it would drag in the guides.
The only place where I've picked up either type of brake linings that fit perfectly time after time was the parts counter at the Ford dealership I worked for.
Yes they charged a premium for there parts but the quality control they demand in their replacement parts justified it.
 
it looks like the drum is rubbing on the top and bottom edge of the secondary shoes, and thats where im hearing it as i rotate it.
 
firechicken1992 said:
it looks like the drum is rubbing on the top and bottom edge of the secondary shoes, and thats where im hearing it as i rotate it.
Click to expand...
Same thing just happen on my 72 Dart, with new shoes & drums from Auto Zone, so I grinded on the top and bottom edge wear it was rubben, but I don't know how things are going to go, ant put things back togeather yet!
 
67Dart273 said:
Please define the problem more specifically. I've seen LOTS of drums where they would "rub" the shoes in one place in wheel rotation, and still worked just fine.

The way I adjust shoes is to adjust them up tight, until you cannot turn the tire. Then back off until the drum rubs somewhat when rotated. This is a judgement call, and you "try" and get both sides about the same.
Click to expand...

For some reason I feel the need to repeat what I said


Just how much force does it take with your hand ON THE TIRE to get past the tight spot? Even though "it rubs" if you can put your palm on the outside of the tire and with just a LITTLE push, rotate the tire past, it's probably FINE

Adjust the darn things, drive it "gingerly" a few blocks, and if everything is OK, drive it a few miles. If the pedal is not real high, but "high enough" to be safe, drive it 10 miles or so, make a few easy stops, the readjust the brakes.
 
Always check the radius of the linings to the radius of the braking surface by hand/eye before assembly. Part stores will send you out the door with 10 inch shoes and 9 inch drums in a heartbeat. I'm not saying this is the case for you. A small amount of break in / wear fit does happen. If there is a sizable gap between the shoe radius and drum radius, something is amiss.
 
i was just thinking id try that tomorrow when i go to my girlfriends house. but i also know a little rub is normal, i just want to make sure everything is fine with my girlfriends car as it is her DD
 
In days of old,, we had a "brake shoe arcing machine", that'd grind on the shoe till it matched the arc of the drums, cuz it changes as the drum wears, or is machined.. That was asbestos dust being ground off, and became frowned upon cuz of health reasons,, so no more matching shoes to drums.. You just wear em in now.. by driving..

So depending on your drum size,, it's common to find the shoes either touch on the leading/trailing edge,, or ,, a few inches right in the middle..

hope it helps

P.S. The shoes will seat faster, if the drums have been machined..
 
I'm with inertia on this one,Shoes will seat to the drum when the shoe high spots are gone.Takes some drive time.
 
Warpage is oft thought of as out-of-roundness in drums, where "run out" can cause rubbing in places ne'er
sought.
 
inertia said:
In days of old,, we had a "brake shoe arcing machine", that'd grind on the shoe till it matched the arc of the drums, cuz it changes as the drum wears, or is machined.. That was asbestos dust being ground off, and became frowned upon cuz of health reasons,, so no more matching shoes to drums.. You just wear em in now.. by driving..

So depending on your drum size,, it's common to find the shoes either touch on the leading/trailing edge,, or ,, a few inches right in the middle..

hope it helps

P.S. The shoes will seat faster, if the drums have been machined..
Click to expand...

Ah your showing your age now. I was going to mention the same thing. A part of the brake replacement that is not checked or done now days is to place the new shoes in the drums to check for fit without the shoe rocking in the drum. We use to re-arch shoes all the time to get a good fit to the drum. I know I have inhaled more asbestos dust in the early 70's than most have in there life. I'm sure at sometime in the future this will be a heath issue for me.
 
Re-arcing shoes has nothing to do with out of round. Therefore if a drum is true, it will begin to rub at some point, "wherever that is," just a little.

ALL drums are going to be somewhat out of round to some degree, if nothing else, a little tiny bit of play in the bearings, etc. Another thing that can aggravate out of round is some jockey overtightening the drum on the brake late, as well as mis--mounted on the hub, as in change a new drum, or warping by overtightening wheel nuts.

The thing is, the OP STILL HAS NOT described the degree. How much force does it take? This might be a problem and it might be nothing.

The only real way to check a drum is to mic it for oversize, then chuck it on the brake lathe and make a scratch cut, turn the drum 1/2 turn and rechuck, and make a second scratch. The two cuts should be on the same side. If not, it was chucked wrong.

[ame="http://www.youtube.com/watch?v=mx2svpjj5II"]Brake Lathes - AMMCO 4000E Brake Lathe Drum Reconditioning - YouTube[/ame]
 
67Dart273 said:
Re-arcing shoes has nothing to do with out of round. Therefore if a drum is true, it will begin to rub at some point, "wherever that is," just a little.

ALL drums are going to be somewhat out of round to some degree, if nothing else, a little tiny bit of play in the bearings, etc. Another thing that can aggravate out of round is some jockey overtightening the drum on the brake late, as well as mis--mounted on the hub, as in change a new drum, or warping by overtightening wheel nuts.

The thing is, the OP STILL HAS NOT described the degree. How much force does it take? This might be a problem and it might be nothing.

The only real way to check a drum is to mic it for oversize, then chuck it on the brake lathe and make a scratch cut, turn the drum 1/2 turn and rechuck, and make a second scratch. The two cuts should be on the same side. If not, it was chucked wrong.

Brake Lathes - AMMCO 4000E Brake Lathe Drum Reconditioning - YouTube
Click to expand...

Rearcing the shoe had nothing to do with the drum being true! After we turned the drums you still had to fit the shoe to the SIZE of the now fresh cut and trued drum. So when the the brakes were applied the shoes would contact the drum, top,middle and bottom to the best of your ability.
 
firechicken1992 said:
it looks like the drum is rubbing on the top and bottom edge of the secondary shoes, and thats where im hearing it as i rotate it.
Click to expand...

The OP mentioned the shoe fit,, I thought I might help fill in the picture, for him/her, and anyone else who might be interested..

sorry if I stepped on your toes....

hope it helps
 
inertia said:
The OP mentioned the shoe fit,, I thought I might help fill in the picture, for him/her, and anyone else who might be interested..

sorry if I stepped on your toes....

hope it helps
Click to expand...

No problem............what you might notice say, if the shoes hit the mid point, which is more typical of an oversize drum, once it's adjusted "as good as it gets," the pedal may be less than rock hard with manual brakes. This is because the shoes are actually flexing with the poor drum contact.

It sure as heck won't stop as it should.
 
I agree with all the above. I forgot he stated they do fit. There is nothing that keeps the linings centered to the axle. Shoes only tanged against bumpers and hold down spring with ample movement. Yet the drum is in a fixed position with minimal movement.
A slightly bent backing plate can cause increased rub. A slightly bent axle flange can cause increased rub. The fact that none of these will cause brake failure is the beauty of the design.
I'll add this... another member posted a pic of his drum brake lining renew and asked, "Does this look right?" Collectively the forum pointed out at least 3 places where springs and things we not placed exactly as they should be.
Pics can help us help you determine if there really is a problem or not.
 
All old front drums and some rear drums had a spring around them to keep them round while under heat unless they were finned. Most of them fell off on the road by now. Find a set or drive it like a grandma. I would suggest discs for your girl. Do not buy cheap lining. A hard Metallic lining should be used. It destroys the drum but keeps it cut true while in use and doesn't create a hot spot.
 
Oldmanmopar said:
All old front drums and some rear drums had a spring around them to keep them round while under heat unless they were finned.
Click to expand...
Interesting. I wondered what the springs around my 65 Dart drums were for. I had assumed they were to increase heat transfer, but your description makes more sense.

I adjust the shoes outward until the drum just slides on with some drag. That is to insure they will work. I then remove the drum and adjust the shoes in a few turns (knocking them in with my palm). The drum then spins freely, so no drag while driving. That makes the pedal travel a lot. I then back up down the street, jamming the brakes hard multiple times, to make the self-adjusters work. The pedal should then be fairly tight. I think all shoes will first contact at just a few points, unless everything was precision machined. But after a bit of use, they should wear to contact the drum evenly. I have even re-used drums or rotors with grooves and the shoes or pads wear to match them. An auto store once messed up in turning a front drum on my 65 Newport, cutting a wide groove on the inner side. Of course they didn't fess up, and I didn't notice until I was putting them on 50 miles away, so I just used them (for 20 years). The shoes would wear into that groove, and I never noticed an imbalance. It did make it harder to remove the drums, having to back off the star wheel using screwdrivers.
 
Oldmanmopar said:
All old front drums and some rear drums had a spring around them to keep them round while under heat unless they were finned.
Click to expand...

BillGrissom said:
Interesting. I wondered what the springs around my 65 Dart drums were for. I had assumed they were to increase heat transfer, but your description makes more sense.
Click to expand...

I read an old service bulletin back in the early 60's,, said spring was to help eliminate the chronic brake squeel the cars had in the 50's and 60's..

I remember that squeel very well, in our 56 Plymouth, my dad told me the noise was from hard linings,, go figure..
 
inertia said:
I read an old service bulletin back in the early 60's,, said spring was to help eliminate the chronic brake squeel the cars had in the 50's and 60's..

I remember that squeel very well, in our 56 Plymouth, my dad told me the noise was from hard linings,, go figure..
Click to expand...

THIS dampens "ringing"
 
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