Strange Lurching Diagnosis Help

[INHWMW]

Success! I got the drum off. And a LOT of brake dust came out of that drum. Now that I have it off, everything looks pretty normal inside. No broken or missing springs, no leaking brake fluid, the only strange thing was the absurd amount of brake dust compared to the other side.

 

[Uncle Gump]

Thats because the brakes have been dragging.

Take a picture so we can see what it looks like...

 

[INHWMW]

Most of the pads have .180 remaining, some are at .240 and one is at .150 at one end. Pretty inconsistent wear, maybe the star wheel was adjusted wrong from the get-go? Or is inconsistent wear from end to end typical?

The drum pictured is the offending side.

 

[Rick W]

Was there any axle grease or brake fluid leaking on the other side? Something that would act as a lubricant and let that side slide, while the one you’re looking at was locking up?

Go back to basics. With the drums off, use a pair of channel locks or something like that to pull on the emergency brake cable. Is it moving back-and-forth? It should. Press down on the emergency brake and see what it looks like, side vs side.

Look at the teeth on the star wheels. are they rounded off? First and foremost, are those star wheel gizmo’s installed in the correct direction. You can put them in backwards, and that’s a problem.

Look at the teeth on the star wheel, is the wear and tear on the left side, the same as the right side?

Look at the adjustment arm that engages that star wheel. Is one side worn down and the other side sharp??

These guys will jump on me, I’m the one who rigs everything, but the cross-section of that lever should be rectangular at 90°. If one is worn, and the other one is sharp, they won’t adjust the same. Here’s where the other guys will jump. If you take a file, or go very easily with a grinding wheel, you can restore the rectangular profile, 90° corners. You want both of those star wheels and adjustment levers to work the same way.

If none of that works, you could put fertilizer and diesel fuel mixed in the rear end, and smack it with a hammer. The axles will blow off into the next county, and it may kill you, but then you won’t be worried about why the brakes don’t work right anymore

No, scratch that last thing.

If all of that stuff looks OK, a brake spring set is pretty cheap. Replace the springs and the shoes, and the drums, and cross your fingers…

If it was easy, they would let women and children do it

 

[sgtsandman]

Don't forget to get the drum checked for being out of round. What looks like a perfectly round drum could be off enough to cause a problem.

Brakes being turned is not a common thing anymore. So finding a shop with a turning machine might be difficult. A machine shop can still check to see if the drum is warped and tell you if it can be cut back to round or not.

 

[Rick W]

I had an afterthought. How many miles on the truck, and how do the rubber brake lines look. I haven’t heard it in a while, but west back I had a car where the inside of the brake lines had swelled, crumping up in the confining space of the outside, rubber, and basically restricted the brake fluid flow. When you stepped on the brakes, there was enough power to get the brakes to grab, but the clogging was so bad that the brake lines wouldn’t completely release.

The rubber brake lines that go to the wheels are usually pretty cheap, so that might be an inexpensive way to also improve the situation.

 

[Uncle Gump]

One would think that if the rubber hose is collapsed... it would surely affect both sides of the rear brakes.

I looked at your picture... nothing stands out being incorrect. But the point where the shoes meet the anchor pin... look closely at the shoes... when that brake assembly is at rest... the shoes should be fully seated against the pin. If they're not... the park brake is hanging up holding the shoes in a somewhat applied state.

 

[Rick W]

One would think that if the rubber hose is collapsed... it would surely affect both sides of the rear brakes.

Certainly not challenging you,I honestly don’t remember how the steel lines and rubber lines run to the rear wheels. The last time it happened to me was on a little Fiat X1/9 if anybody remembers what that was. They were rubber lines to all four wheels, but I don’t remember how the steel lines ran out to them. I only remember because they were like five or six dollars each, and I just replaced them all when I couldn’t figure out what was going on. And it did solve the problem.

I still have a box X1/9 parts, an extra roof, and a couple bumpers if anybody wants them. They’re all too small to slap on a Ranger.

 

[INHWMW]

175,000 miles on the truck.

I have been playing with the idea of new brake lines for a while, the metal lines are rather rusty.

I have the drums and wheels back on, the offending wheels spins mostly freely, but I can feel a slight stick at a certain point of rotation. Does seem to indicate a warped drum. I'm gonna go for a drive and see how the brakes feel now that the adjusters have been reset and all that dust cleaned out. After all, I now know I can get everything back off if I need to.

 

[INHWMW]

Post drive, the lurching stop-and-go motion is gone, hooray! However, my brakes are noticeably softer. I suspect this is due to how far back I had to turn the auto adjuster in order to get the drum off. Would this just clear up with time? It's called an auto adjuster, so I'd think they'd adjust on their own, but I don't know everything.

 

[SenorNoob]

I've always heard to brake hard in reverse to make the adjusters work faster. IDK if that's true or not.

 

[INHWMW]

I've heard that before as well, I did that a few times, but I don't know how long/how many times it's meant to take.

 

[Uncle Gump]

It's true...

I typically get my adjustment close... then stab the brakes backing out my driveway several times. If the adjustment was out 30 or 40 clicks... you'd have the stab the brakes 30 or 40 times.

If everything is proper... they shouldn't over tighten.

 

[sgtsandman]

Post drive, the lurching stop-and-go motion is gone, hooray! However, my brakes are noticeably softer. I suspect this is due to how far back I had to turn the auto adjuster in order to get the drum off. Would this just clear up with time? It's called an auto adjuster, so I'd think they'd adjust on their own, but I don't know everything.

It is possible that there was some residue on the drum. It happens some time. Just keep an eye on it for a bit as the brakes readjust. The pulsing may come back if the drum is warped.

 

[Rick W]

When you put the drums back on, did you snug up those star wheels? Especially if you had to back them off a lot to get the drum off.

What I usually do when I put everything back together, with the tires off the ground, I just spin the tires and tighten up the star wheel slowly. The star wheel turns a lot easier in the direction it’s supposed to go.

What should happen is that it spins spins spins, and then you reach a point tightening up the star wheel, that it will just barely start to drag. If you tighten it a little bit more, it will lock up. You want to get to that point where just barely scuffs. If you tighten it too much, just back it off a couple clicks.

After it seems like you have it correct, banging around with that dead blow, hammer, and wiggle the wheel all around. The shoes have to be centered on their pivots, and sometimes banging it around will help them see correctly.

Then as you drive it, it will adjust to the right place. It might take a while if the shoes are too far out, and if the pads are too far out, that could also be unsafe.

As you’re doing that tightening, if it doesn’t start to tighten up smoothly, and it’s more like a chunk chunk chunk, even a mild chunk chunk, most likely the drum either has a bad spot or the inside is out of round.

I always used to get mine turned, but I don’t know if anybody does that anymore. But the drums are not that expensive.

Hope it helps