Brakes pulling to left

[Roadcuda]

My friend has a '72 Dart, 4-dorr, 225, auto. When he first got the car we did a brake system rebuild with all new wheel cylinders, rubber lines, and steel lines where necessary. Everything worked well at first but after a while it started pulling to the left. We readjusted the front brakes which helped but it didn't last and has progressively gotten worse. One of the original lines we didn't replace finally gave out so today we did a complete rebuild of the steel lines. And of course it still pulls to the left. So we pulled the drums to make sure everything was hooked up right which it was. There was one thing I noticed though. The cable for the self adjusting brakes was slightly loose on the right side which left the adjuster sitting below star wheel, not toughing it. It's tight and touching the star wheel on the left side. Could the fact that the slack cable on the right is not adjusting the wheel, but is on the left and causing that side to grab first and pull to the left, or could there be something else going on that we can't see. thanks in advance.

 

[BillGrissom]

A few things to check:

Most brake shoe sets have 2 different length linings. You have to look close to notice. The longer lining goes on the aft side on each wheel (front and rear). If you had all short linings on one side, that side would be weaker.

Insure your self-adjusters are on the aft side of each backing plate. You can find photos posted here, plus look at the factory manual. I think the adjuster should be tight against the star wheel to hold that position. I used the later style adjusters on my 65 Dart. They have an in-line spring instead of the torsion spring. Not sure about 1972.

Both of the above were wrong on the 64 Valiant I bought, plus somebody stuffed the "grease catcher" cup on the backing plate with fresh grease so it got on the shoes. All parts were new and clean so I put it back right.

Drum brakes are much more fickle about the coefficient of friction than disk brakes. That is due to the "self-amplifying" effect of the shoes jamming against the drum. A little leaking brake fluid can gum up the shoes and make them self-lock. Always clean the shoes with brake cleaner as a last step since even a greasy thumb print can make a big difference.

 

[cudajim]

More important than checking your work on the brakes you really want to check the front strut rod bushings on the inside. If you have not replaced them they're probably worn and every time you mash on the brakes the front-end geometry moves around way more than intended. I had this problem on my old 67 Barracuda and all the tweaking in the world did no good till I replaced the bushings with solid Moog bushings. It made a big difference!

 

[cuda65vpt]

Also have you replaced the rubber brake hoses? If you haven't there could be one blowing up like a balloon and not making the brakes work properly.

 

[RedFish]

the greatest advance of disc brake engineering is a straight line stop.
About all you can do is make sure the cable guide still has the little neck on it that holds it in the shoes hole properly. Beleive it or not, such a tiny item can throw drum brakes to one side. Same applies to a hardened steel thrust washer in the adjuster. Loose that little washer and the adjuster will refuse to turn allowing the adjust paw to wear teeth from the star wheel.
Bottom line, closely inspect every piece of drum brake hardware large and small.
All most forgot... the cable itself has nearly zero stretch so that is not the problem.
Good luck

 

[pishta]

drums the same size? Shoes look to be wearing the same? Drums suck.

 

[Roadcuda]

Thanks for the great ideas of things to look at! The rubber brake hoses were replaced. The adjusting screw appears to be free as I was able to move it easily with the adjusting lever. As for the drums I know they were turned so if they are the same size or not, that I don't know. Teh cable guide is in it's proper place. We'll have to check the wheel cylinder dia. and strut bushings.