Are star wheel adjustable brakes not actually self adjusting?

[The motor guy]

They're supposed to tighten everytime you hit the brakes in reverse when you have drum brakes, but neither my old dodge or my landscape trailer with dexter electric brakes does it. Even holding the lever on the brake controller and backing up in reverse real fast does nothing.

 

[Analog-1]

I have never seen a case that self adjusters actually work.

 

[Astro14]

They're supposed to tighten everytime you hit the brakes in reverse when you have drum brakes, but neither my old dodge or my landscape trailer with dexter electric brakes does it. Even holding the lever on the brake controller and backing up in reverse real fast does nothing.

They work, but it can take several applications to turn the star wheel a meaningful amount. There’s like 20 points on those wheels, so each application turns the star wheel one click, or 15°, or some tiny fraction of a millimeter on the threads.

Every service manual I’ve ever seen has you adjust it by hand before engaging the self adjusting. If you’re a couple of turns off on the depth of that star wheel, you’re gonna have to back up literally hundreds of times applying the brakes before you get the brakes into adjustment.

However, if it is not working at all, you might have a bad return spring, or the arm itself may have worn to the point where it’s a rounded edge that’s catching each tooth on the star wheel. Take a good look at the self adjusting mechanism.

“Back in the day “ I had to take a file to a couple of those adjusting arms to reestablish a nice square edge that would catch the points on the star wheel.

 

[Astro14]

I have never seen a case that self adjusters actually work.

I owned several cars with rear drums, one with front and rear drums.

They all worked.

Now, they don’t work if you neglect them, they don’t work if the springs go bad, and they don’t work if you fail to replace parts that have worn out, like the star wheel, or those adjusting arms I described above.w

I currently own a car with drum brakes that are not self adjusting, and getting them correct, is an art.

This problem should be relatively simple to figure out.

 

[hrv]

They work, but it can take several applications to turn the star wheel a meaningful amount. There’s like 20 points on those wheels, so each application turns the star wheel one click, or 15°, or some tiny fraction of a millimeter on the threads.

Every service manual I’ve ever seen has you adjust it by hand before engaging the self adjusting. If you’re a couple of turns off on the depth of that star wheel, you’re gonna have to back up literally hundreds of times applying the brakes before you get the brakes into adjustment.

However, if it is not working at all, you might have a bad return spring, or the arm itself may have worn to the point where it’s a rounded edge that’s catching each tooth on the star wheel. Take a good look at the self adjusting mechanism.

“Back in the day “ I had to take a file to a couple of those adjusting arms to reestablish a nice square edge that would catch the points on the star wheel.

you have to back up and stop many times for them to adjust enough...Just a few times of doing it will not be enough...and yes if they are clean and free they do work...

 

[Jdeere562]

you have to back up and stop many times for them to adjust enough...Just a few times of doing it will not be enough...and yes if they are clean and free they do work...

Clean and free is the key word. In rust bucket states, they will get frozen with rust.

 

[JohnnyG]

As hrv said. While backing up, hit the brakes multiple times, medium hard, you don't have to come to a complete stop.

 

[eljefino]

It's not always backing up and stopping-- sometimes you have to use the parking brake. There are intellectual property reasons they're done a variety of lousy ways.

Shoes are supposed to "float" inside the drum, that's a servo action that helps apply them going forwards and helps move the series of levers going backwards, if that's how they're set up. So you don't want things clogged up with old brake dust inside. Grease/ anti-sieze on the shoe where it contacts the backing plate is somewhere between a good idea and a matter of religious debate. Rusty hardware-- those springs and nails-- could have a deleterious effect on performance.

For me the best maintenance is removing the adjuster and putting anti-sieze on its internal threads. The things always get stuck. IDK if that fixes them, since I also manually adjust while I'm in there, but it does fix a potential failure point for at least a little while.

I also take the opportunity to grind the little lip off the inside of the drum, so it doesn't catch on the shoes. Lets me pre-adjust more easily from the outside, vs using a screwdriver from the inside through that awkward little hole.

 

[The motor guy]

you have to back up and stop many times for them to adjust enough...Just a few times of doing it will not be enough...and yes if they are clean and free they do work...

Well I back up out of my driveway everyday. Is that not enough to keep them in check?

 

[Trav]

I cut my teeth on drum brakes over 50 years ago, the biggest problem I see is people cleaning the adjuster and mixing them up. One is right hand thread and the other left hand. It cant work if installed on the wrong side. Installing the cross bar backwards is also common.

 

[fdcg27]

There are such things as drums needing manual adjustment.
This was the case with our '76 Civic as well as '76 MGB.
Easy peasy and you knew when it was needed when the brake pedal was low and the parking brake became ineffective.

 

[D60]

I just did the rear of an '00 Cavalier and there are no windows for a spoon. I guess you hope you never have a deep groove and need to back off manually.

Those adjusters also seemed weird because the arm rested literally on the side of star wheel -- it looked to me like it would need to swing down A LOT to then catch a tooth and pull it up

 

[Astro14]

I cut my teeth on drum brakes over 50 years ago, the biggest problem I see is people cleaning the adjuster and mixing them up. One is right hand thread and the other left hand. It cant work if installed on the wrong side. Installing the cross bar backwards is also common.

From the days of drum brakes - disassemble one brake ONLY.

Leave the other side intact, to see how springs, shoes, and hardware are mounted. Which shoe is leading (sometimes they have more friction material) and where it’s located. The other side is your template. When the first side is done, complete, and correct, then, and only then, take apart the second side.

 

[CharBaby]

The term “self adjusting” means that you’ll have to adjust them yourself.

 

[jhellwig]

They do work in rust bucket states but you cant just ignore them. Sometimes you have to go to an empty parking lot or road and back up several times hitting the brakes hard. Same for just getting on the brakes hard sometimes going forward helps keep the glaze off of things.

 

[BHopkins]

@Astro14 is right. Self adjusting brakes will keep properly, or at least close to properly, adjusted drum brakes adjusted correctly.

What the mechanism will not do is properly adjust a newly installed set of shoes, that have been left far from correct adjustment. Maybe, eventually. But not anytime soon.

 

[The motor guy]

@Astro14 is right. Self adjusting brakes will keep properly, or at least close to properly, adjusted drum brakes adjusted correctly.

What the mechanism will not do is properly adjust a newly installed set of shoes, that have been left far from correct adjustment. Maybe, eventually. But not anytime soon.

Maybe I've been doing it wrong then. Sounds like I need to repeatedly press the brake pedal when stopping vs just one single stop.

 

[nate379]

From the days of drum brakes - disassemble one brake ONLY.

Leave the other side intact, to see how springs, shoes, and hardware are mounted. Which shoe is leading (sometimes they have more friction material) and where it’s located. The other side is your template. When the first side is done, complete, and correct, then, and only then, take apart the second side.

Or take photos or video. Which 20 years ago wasn't so easy!

 

[ecotourist]

Maybe I've been doing it wrong then. Sounds like I need to repeatedly press the brake pedal when stopping vs just one single stop.

You get them close manually, then do many many stops in reverse.

Each stop gets only one click on the star wheel and if they're not even close, good luck.

 

[The motor guy]

Or take photos or video. Which 20 years ago wasn't so easy!

Exactly. That way when you forget because you're 3 beers in and slightly buzzed, you can look at the other side