1960 Dodge Dart Front Brake Issues

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JLanzino

JLanzino

GM Specialist
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Hey Guys,

I was having brake issues last year and lost the front brakes this year, the wheel cylinders were shot, so I ordered up 4 new front wheel cylinders, put new front brake lines & flex hoses, but for what ever the reason the Right front drum keeps locking up. I tried everything I cant figure it out :banghead:

Any help is much appreciated!!
 
did you change the shoes? In the old days the brake shoes were "radiused" in a machine before the shoes were installed. this was done at the garage where the brake work was being done. Nowadays, those machines are few and far between but the original problem of the shoe having the wrong radius (too much diameter for the drum) was that the brakes would lock up. the edges of the shoes would dig into the drum. this is a big problem for those that buy cheap shoes for their chevy cavaliers. Many of them have this problem with the rear drum brakes. the smaller the drum the worse the problem. You could get out the old 4 inch grinder and grind the edges off the shoe a bit, kind of chamfering I would call it. this would be the only thing that I can think of that might cause this problem other than maybe some type of wrong hardware on the self adjuster or something like that. Another long shot would be a out of round drum or loose wheel bearing but not likely.
 
You replaced the shoes, ?.

If you used the old shoes,, and either side was contaminated with fluid, or oil.. you'll likely need to replace the shoes, as they're near impossible to clean,, or having them re-arced may work..
 
I reused the shoes because I replaced them 5 years ago and have done minimal driving, the brake fluid never touched the shoes, the shoes and springs, & spring kit, and the Drums were replaced, and now I did the wheel cylinders flex hoses and brake lines.
 
Wow, that is a tough one for sure. Almost out of ideas, last thoughts; primary and secondary shoes mixed up, bad return spring in there somewhere, wrong self adjusting mechanism (or part of it). No spring in the wheel cylinder (not sure how that might affect the problem). Mix-up on the wheel cylinder, eg, wrong diameter piston (may have been boxed wrong). Improperly assembled (I doubt that one though as you seem like you know how to wrench on stuff) or, for some strange reason the fluid is not wanting to return, i.e getting trapped in the wheel cylinder and not releasing. (Old rubber brake lines would do this when they would get old and shrink up, constriction would not let the fluid go back when releasing the brake pedal) and, last but not least, the shoes are "hanging up on something." I don't know what that could be....just thinkin out loud FWIW. good luck
 
Locks up turning by hand, or when rolling?
Like mentioned a 4 inch grinder may help solve that if it ends up you can't find any other reason.
The idea would be to taper the ends of the brake shoe for the first 1/2 inch or so.
1/8 or so deep on the taper at the shoe edges ( leading edge) top of the front shoe and bottom of the rear shoe.

"i.e getting trapped in the wheel cylinder and not releasing. (Old rubber brake lines would do this when they would get old and shrink up, constriction would not let the fluid go back when releasing the brake pedal)"

This is an easy one to eliminate, even though you have new hoses.
While it's locked loosen the bleader screw and it will release if thats what is causing it.
Wouldn't be the first time a new hose was mismanufactured.
 
Locks up while rolling at low speed, I will grind the edges and re adjust the shoes again and hope it works, I can see the wheel cylinder retracting, maybe the shoes are too tight?
 
I'd try lightly sanding the shoes by hand , and make sure there is some type of grease between the backing plate and the shoe contact points
 
JLanzino said:
Locks up while rolling at low speed, I will grind the edges and re adjust the shoes again and hope it works, I can see the wheel cylinder retracting, maybe the shoes are too tight?
Click to expand...

To tight never seems to cause a lockup when you press the brake, but to loose does.
It lets the shoe cam into the drum harder.
 
Try changing the shoes from side to side,, if the problem follows the shoes,, replace the shoes....

You mentioned an issue before losing the front brakes,.. What was that issue??

hope it helps
 
Pull the durm and the shoes and put the shoes inside of the drum and hold then in place; the idea is to see if the radius of the shoes matches the radius of the drum; the should match up all along the shoe material. See if there is a gap in the middle of the shoe material; if so then the shoe ends need to be ground down as above at the very least. Better than than, you should try to find a brake shop that still has the old machine for what was called 'arcing' the shoes to get the shoe and drum radii matched up.

Also, shoes that sit a lot can absorb moisture, which can make them grab badly and even lock sometimes. I only know to put them in an oven for a while at low temp to try to drive any moisture out, or replace/reline the shoes to cure this. You can also hand sand the surfaces with a corase grit drywall (mesh) sanding material and then clean them with brake-clean to get a fresh braking surface, but I don't think it will change anything in this case.

I would also go back in and replaces ALL the springs in the brake assemply (see if you can get kits from NAPA), check that the springs are all installed right, and make sure the primary and secondary shoes locations are right.
 
Im getting the drums machined, and sanded down all 4 shoes, and will grind down the edges on the shoes.

Im hoping this helps if not I will be replacing shoes & spring kit again lol
 
Tough one. If anything gummy gets on a forward shoe, that can cause a "self-jamming" effect, i.e. if you press the brakes, there is enough friction to hold the shoes against the drum even after you lift your foot. Can happen from just a little brake fluid on the shoes (i.e. my 4 yr old Chevy S-10 rear drums). They should release when you stop, if the spring returns are fine. See if that is true.

If not, (as suggested) suspect the shoes aren't returning or something is forming a "check valve" in the fluid system - degraded hose inside, stray rubber bits, rust clumps. Did you blow out the lines before installing the new wheel cylinders?
 
Update!!

I ended up sending my drums out to get machined, and grinded the edges down off the shoes, then put it all back together

The drums were extremely out of round, once I got them back and put the grinded shoes in, it brakes perfectly now it seems, no locking up at all!

Big Thanks for all your help guys, My Shop teacher and My friends father (it seems to pay to know Chrysler guys lol)
 
JLanzino said:
Update!! ended up sending my drums out to get machined, and grinded the edges down off the shoes, then put it all back together
Click to expand...

Drum brakes should NEVER be worked over without turning or replacing the drums.

On disk brakes, "sometimes" you can sneak by, but in reality they should be turned, as well

I've got a perfectly good Ammco disk / drum machine, but for most of you the shipping would be killer.
 
I'd love to have my own turning machine for all the cars I work on. Out here in N. California they want $12 minimum just to tickle a rotor or drum.

Glad to hear you solved the problem.
 
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