The Stovebolt Site Forums The Shop Area General Truck Talk Brake's star wheel adjuster question

Now that the front end is done, sort of(king pins and brake pads), I've moved to the rear brakes and found something I'm not sure about. It's been a few years since i put the brakes on, and my front ones were almost gone on the short pad, but barely worn on the long one (I never can remember which one is primary and secondary). Well, this morning when i pulled the rear drums, I was shocked to see the rear pads on the passenger side were only worn a small bit at one end, and looked as if they hadn't been touched at all on the rest of the shoes. I looked down at the adjuster, and it was closed all the way! Got to the other side, and it was the same way. And I had for some reason applied anti seize to the threads, so now I'm asking myself did I forget to adjust the rears? (I'm wondering if I changed the rears, moved to the front, changed the fronts and adjusted them, then forgot to go back and expand the rear shoes), or did putting anti seize on them cause them to close up over time? Judging by the way the pads are hardly worn, I'd say i forgot to adjust the back ones. But now i'm asking myself, why did i put that anti seize on there? To be honest, I'm a little bit disappointed in the loctite anti-seize because when i tried to unscrew them (both), I couldn't get them to budge by hand. Then I tried a vice grip on one end and my fingers at the other, but I couldn't get them to budge until I took them in and put them in the vise on my bench and used channel locks to break them loose. They're fine now, and are cleaned up and in good shape. Question here is, should the star wheel adjusters be lubed at all? and if so, what should and shouldn't be used? I think all the times before that last time, I'd just used 3 in 1 oil. They were probably in bad shape when i took them apart last time, is what I'm thinking my reason for the anti seize was at the time. Apparently for the last 4 or 5 years I've been driving on front brakes only. What's everybody else say?

Are you dealing with Bendix or Huck brakes? Hucks have a cup shaped adjuster on each end of the wheel cylinder, while Bendix brakes have a single adjuster at the bottom that bridges the gap between the shoes. It's not uncommon for a Huck brake to wear only one lining while the other one on the same wheel looks brand new. Bendix brakes are self-energizing, meaning that the rotation of the drum forces the shoe assembly toward the rear, wearing the longer rear lining a bit more than the short one in front. Huck brakes should have the same length linings front and rear, although some rebuilders used the wrong linings on the Huck shoes.

Brake adjustment does not affect the wear rate of the linings- - - -the only thing an out of adjustment brake will cause is a low pedal and/or the necessity to pump the brakes to get any stopping effect. It would take a restricted brake line or a plugged up flex line to keep the rear brakes from wearing.
Jerry

They're bendix brakes, with the star wheel adjustor on the bottom. They also have a short and a long pad on all 4 wheels. But you called it when you mentioned pumping the brakes. I thought it was just an old truck thing, but I've been pumping those brakes ever since I got this truck almost 10 years ago. Sometimes I feel like I'm at a hootenanny, I'm stomping my foot so much when I come to a stop. It's a relief to know that if I adjust these out this time, maybe that will stop. But I still am thinking that with that adjuster completely closed (not expanding the brake shoes at all) must be why the old pads aren't worn at all, except for about 1 1/2" at the ends of the 4 pads. I still can't believe I forgot to go back and adjust those rears. Even more, I can't believe I've been driving around for years (my daily driver, everywhere) on the front brakes. The short pad on both fronts was worn down from about 3/32" on one end to paper thin on the other.

Adjust Bendix brakes by tightening the star wheel until you get a firm drag (not locked up) at each wheel and back off one turn of the adjuster. That's 10 clicks on a standard adjuster, or 20 on the fine tooth wheel used on self-adjusting brakes. Ignore any drag noises you might feel or hear after backing up the star wheel. The shoes will self-center every time you apply the brakes, but there's no way to guarantee there won't be a little scuff noise once you start backing up on the adjuster.
Jerry

If they're wearing just on the end of the shoes with the adjuster, they weren't properly set up. There's a major adjustment required which involves loosening the anchor bolt at the top with the adjuster tightened completely, then tapping the anchor pin and or backing plate to center the shoes. The anchor bolt has a vertical slot to allow the top of the shoes to be adjusted up or down. The procedure is in the shop manual, and is done before the final adjustment of the star wheel.

That's caused by running standard radius lining in an oversized drum. They will only contact at the ends, and take a long time to "wear in" to full contact with the drum. Use water-based glue to attach a piece of coarse sandpaper to the inside of the drum, and scuff the new linings back and forth to match the radius. Once that's done, use boiling water to remove the sandpaper from the drum. Then buy a crash helmet- - - -if you stomp the brakes like you used to, you'll bounce your head off the windshield!
Jerry

Jerry, I’m not understanding your logic. If the drum was oversized (larger ID) and the shoes were standard, wouldn’t the shoes contact first in the center of the shoe?

It depends on the amount of oversize, or out of round of the particular drum. When radius-grinding the linings was a common procedure, we would grind the linings to a slightly smaller radius than the drum so the center would contact first, and when the pressure of the shoes against the drum would push it into an oval shape, there would be full contact with the lining. Otherwise, there would be toe and heel contact only. Since the tree huggers will give anyone who dares to grind a brake lining 30 days in the electric chair these days, sanding the linings into full contact is about the only option left to anyone who wants to do a good brake job. The sandpaper creates a slightly smaller radius anyway, so the result is about the same.
Jerry

Wow, this is a lot of information! That's why I love this forum. I learn something new every time I get on here. I took another look at the drums when I went out and put the new brakes in yesterday evening. One isn't TOO bad, but one has some pretty deep grooves in it, so I'm going to put new drums on the rear. I usually order stuff that is specific to this truck from classic parts, but sometimes I worry about the quality of parts that they sell. For instance, those last brake shoes came from them. Checked NAPA's site, but the wheels they're showing on line don't match (look like) the drums I have on there, and I want what came on the truck, not somebody's idea of good enough. I'm going to see if I can track down a local machine shop that will let me know if there's enough left to turn the drums I have. (My micrometer is an 'edge' type, and won't measure around the lip on the drum). thanks for the tip on sanding the pads. Just laying the shoes inside the drums before I install them to check the fit is something I never thought of doing. That explains why the end was slightly worn. But it was only one end on both sides that wore. Also, the fact that the adjusters seem to never have been run out from their 'closed' position was a big error on my part. Thanks for the help on this, guys. I really appreciate it. Lee

Back to report the progress. I ended up having the drums mic'd and turned at a machine shop. They look good, so I took the new one's back to NAPA. After putting the drums back on and attempting to adjust the star wheel with the tool from my brake kit, I was getting frustrated about how long it was taking to get some drag against the drum, so I pulled the drum off to check how far it had expanded on the star wheel adjustor, and it hadn't moved. So, apparently, the last time I put on new brake pads and "adjusted them by sound", the sound I was hearing was the wheel clicking off the tool and snapping back to it's original position. Not sure how I heard the drum dragging on that install, but I must have been imagining things, since the adjustors were completely closed when I opened them up this time. My fault! It never occurred to me that, after backing the adjustor off those 15 clicks would allow me to open it up and check my work last time. Duh.
So this time, after finding the adjustor wasn't expanding, I got out my vise grips and manual grabbed the wheel and turned it one click at a time with the drum off, occasionally nutting the drum back on to check for drag. At this point, I also found out that by just sticking the drum on the hub would allow the brake to drag a bit just because the drum was off a little by not running down a few nuts. (Probably what I did last time). Anyway, I tightened them down until they were dragging, then backed them off the 15 clicks, ending up with about 5/8" of adjustor thread showing on the passenger side and about 1/2" on the drivers side. I still can't believe the star wheels weren't turning after I figured it out. I stuck that adjusting tool in there and held pressure on it as I turned it, and it sure felt like it was clicking down to the next spot. I was really surprised when I pulled the drum to see they hadn't budged. And I cleaned the heck out of them when I had everything apart, so they were spinning freely when I put them back in. But this does explain why I ended up with nearly new pads on the back when I pulled them off the other day. What's weird is that the front adjustors worked fine. I hope. Hmm... maybe i'll go back out there and pull the front drums off just to make sure I wasn't imagining rubbing noises when I adjusted those! But they were the two that HAD adjusted out correctly the last brake change, so probably not. But now, I'm going to check them anyway. The wheels have to come back off to put new tires on them before I align the front end, so at least that'll be easy.

Jerry, I really don't feel like pulling those shoes again after all this, but, what would you recommend per the 'water based glue'? That's a new one on me.

I use plain old Elmer's white glue, or the least expensive generic I can find- - - -not the "new, improved" waterproof stuff that costs twice as much. Even wallpaper paste would probably work. All it needs to do is firmly attach the sandpaper to the inside of the drum for a little while. Once you've got the linings scuffed into the drum's radius, a quick application of boiling water dissolves the glue. You could even leave the shoes installed, and adjust them to scuff against the sandpaper-lined drum. I've never done it that way, but I don't see why it wouldn't work just as well. I usually use a piece of 60 or 80 grit paper that fits a body shop "air file". Wear a good dust mask when you use an air gun to blow away the sanding dust.
Jerry

Thanks, Jerry. I wasn't aware that Elmer's glue was water soluble. Also never occurred to me that the pads weren't made to fit the drums. (Unless my drums are out of whack. But I always thought that when they turned them, they brought them true.)

When a drum is turned, the radius changes. If the shoes aren't matched to the new diameter, it takes some time for everything to "wear in" for full contact between the linings and the drums. A good brake job used to include radius-grinding the linings to match the drum diameter, but the snowflakes with lace on their drawers these days would give a mechanic who creates any brake dust 30 days in the electric chair!
Jerry