Front brakes on a car

While we"re off the subject :) I have an 87 Ford Ranger with one drum brake on the rear end that likes to constantly tighten. I"ve pulled it apart several times, once I even replaced everything in it, and it still over-tightens. Has anyone ever worked with drum brakes enough to tell me what"s going wrong? The right side works great, but the left side keeps locking up.

Have you checked the e-brake cable on that side? They have a nasty habit of freezin' up.

Just a thought,

Allan

Call me thick-headed if you want; but I just don't see how an automatic adjuster can ever, under any circumstances, "over tighten".

If it were to be installed "backwards" (end for end) it would, of course, be totally inoperable.

If a left side adjuster were installed in a right side drum (or the other way around), it would be forever "ratcheting" on the pull-stroke and would not tighten a thing.

But, even if the star wheel were indeed moving on the ‘slop’ stroke, it would be always trying to “loosen” the brakes, because the threads of it’s shaft and barrel are backwards (left vs right sides).

Further, by their very design, an automatic adjuster needs lateral "movement" of the shoe(s) assembly against the backing plate to obtain it's throw.

Additionally, since the adjuster assembly is always located at the secondary shoe, this ‘movement’ has to come as a result of the shoes being applied while the vehicle is moving in reverse.

Take it a step further: If the whole she-bang (backing plate, shoe assembly, and the drum) were switched left to right (which is impossible, because of the e-brake cable mounting), the adjuster would indeed engage during brake application during forward motion (if there were enough movement of the shoe assembly against the backing plate). However, it would still only adjust to the “correct” tightness and would not “over tighten”.

The upshot of all this is that the tighter the shoes get to the drum, the less the adjuster mechanism moves until it reaches a point of not moving at all.

Can ya help me out on this one, 'cause my old pee-brain just can't grab the concept. How could an automatic adjuster ever possibly over tighten?

Allan

This is actually a very common problem. Proper operation is for the brakes to self-adjust only when going in reverse. The backwards adjuster is self-adjusting every time the brakes are applied going forward. This causes that brake to drag.

A common cause for this is working on both brakes at one time. The guy gets one right and then does the other one the same way... only it's wrong. Unless you are real familiar with brakes, it's usually best to do one side completely and then do the other.

Ron

This has been a problem ever since I got the truck, so I went ahead and replaced everything last year to see if that would fix it, naturally it didn"t. When I put them together, I only did one side at a time, not starting the other one until the drum was back on the first. That way I wouldn"t use the other one as a reference, get confused, and screw something up.

Now, when Allan said something about installing the self-adjuster backwards, I think by that he means the star wheel. There"s only one way my star wheel can go in and work, otherwise it would be forever loosening and worthless wouldn"t it?

Other than that, the only thing I can tell you is I set it up the way the book tells me to do it for the left side, and it acts just like it used to. A prime example of this is when I first start my truck and put it in drive, it"ll idle down the driveway on its own, then there will be a really loud clunk, and it"ll stop, and after that I"ll have to fight a loaded brake all the way to town.

On a side note, sometimes I"ve noticed when I get to town, do whatever I have to do, and come home, on the way home I"ve noticed sometimes that brake won"t be locked anymore. I would think once it locked, it"d stay locked. What"s the deal with that?

Your symptoms are classic for a reversed self-adjuster. The brake on the bad side is self-adjusting with each brake pedal application going forward. Bad news.

The reason it loosens up after a time is you are simply wearing the drum away.

Wrong/damaged/reversed shoes can also cause this but it's time to stop guessing.

Take it to a brake pro and explain everything you did. Let him fix it. If he offers ceramic (Dura-Stop) shoes for that model, let him install those.

Someone else pointed out (correctly) that brakes are too important to be fix by "trial & error". You've reached the limit of what you can do and there's no shame in that at all.

Be safe, and let us know what it was when you get it fixed!

I'll be darned. Never heard of that one.

But, there's a whole lot I haven't heard about. :>)

Later,

Allan

There's a special silicone grease for brakes that you should use, rather than a petroleum-based grease. Rubber parts in brake systems don't like petroleum.

Now go back and play with your Tonka toys instead of trying to "one-up" me. You aren't smart enought, not even on your best day!

I don't think that hydroscopic is a real word; at least not in the English language that I'm familiar with, anyway.

Perhaps you meant hygroscopic?

And, I’m not trying to “one-up” you either ‘cause I know darned well that I'm certainly not smart enought. :>)

Just havin' fun with ya,

Allan

The primary advantage of anti-seize over plain grease is that no matter how hot the parts get, the glass beads keep the parts from touching and therefore wearing. Another advantage is that anti-seize is very "sticky", won't wash or wear off, protecting the parts from the elements, preventing corrosion.

I've never come across an anti-seize that claims to have glass in it. And don't think glass would be much of a lubricant.

Permatex's web site lists aluminum, copper and graphite as the main ingredients in their standard antiseize. They also carry straight copper and nickel-based anti-seize. I don't see that any of them are recommended for brakes; they've got a special lube just for that purpose.

• Permatex specialty lubricants

You are correct, not all anti-seize products are to be used in disc brakes systems. You have to read the label/packaging.

The correct anti-seize is one that says "made for use in disc brake systems and other high-temperature applicatons".

Just an example to show how specialized anti-seize has become... if you use the wrong anti-seize on a O2 sensor, the engine goes into open-loop. The reason? Only an electrically conductive anti-seize may be used on self-grounding electrical parts, like O2 sensors.

It was OK before you replaced the pads, but now the piston is sitting in a different location and is sticking.

Replace the caliper; you might as well do the other side while your at it. You'll need to bleed the brakes when you're done

You did put disc brake anti-seize on the caliper bolts, right?