14BFF drum brakes, WTF is going on

[Mastiff]

I took the Blazer for a test drive today to check out my t-case rebuild and let the u-bolts settle some more (I get more turns out of them every drive). Anyway, the rig seemed sluggish and when I got back I smelled the heat from one of the rear drums. Jacked it up and was unable to turn the passenger side by hand, but the driver's side had no drag at all. I always try to adjust the drums for just a hint of drag.

While I had it up, I tested the parking brake, and it worked great on driver's side but seemed to have minimal impact on passenger. I could still turn it by hand with the parking brake pedal maxed out.

Finally, the most concerning thing, I fired it up on the stands and put it in reverse. Max brake pedal pressure was unable to stop the wheels. They slowed almost to a stop, but not all the way. I'm pretty sure that indicates really weak braking back there, right?

I've bled probably a gallon of fluid through these brakes, but never felt really confident about it. The flow has always been minimal during bleeding. I've had assistants help and used a pressure bleeder. I'm not sure this is it, but maybe air in the lines would show this symptom? The parking brake stuff may be totally unrelated, or maybe I screwed up the rebuild? I pretty much replaced everything to do with the brakes... Could there be any prop valve or MC weirdness inhibiting the rear brakes? I replaced to MC with a 1-ton model, but everything else is the same.

 

[rampage]

From the diagram it seems like everything is assembled correctly, all the springs and levers for the passenger side are in the right place and the primary shoe is facing forward. My first thought was that you had a blockage in the passenger side hard line but that wouldn't explain the parking brake issue (I think they're related). It almost sounds like one of the shoes is moving but the other isn't. How are the pads on the backing plate that the shoes ride on, do they have any burs or lips and did you put a little anti-seize on them? Do you notice any wear marks on the shoes (they should both show some scuff marks from rubbing on the drum). Are the drums new or at least turned to make sure they are true?

Edit: That blue spring on top doesn't seem to be under tension at all, it seems like the paint is holding it together. If it is then take it off and bend it to break the paint or you may need to cut a couple turns off the end (and make another hook) in order to put it under tension.

 

[Mastiff]

Thanks for the reply. That pic is from when I assembled it a little while back. I'm going to pull the drum off and see if anything has changed, and I can get another look at that spring to see if the paint has cracked at all.

Downside of 14BFF: getting the drums off is a bit of work...

 

[rampage]

If that spring is bonded together it's acting like a solid piece of metal and not allowing the secondary shoe from moving which is the shoe that does most of the braking, that's why it's thicker than the primary shoe. If only a couple coils are separated then it'll be stiffer than it should be. Instead of bending it, force a knife or something between each coil. Only cut a coil or two off as a last resort.

 

[Kain]

also check the rubber line to it if its old might change it

 

[Mastiff]

I pulled it all apart and the parking brake problem is obvious. The parking brake arm (the steel part that connects to the back shoe) was bent like hell and bound in position. This no doubt happened when my axle fell back when my u-bolts loosened up. The parking brake cable must have been the thing that held the axle on the truck, and bent that arm. I should be able to bend it back into shape and get that to work.

Regarding the slipping brakes, I found that the shoes on both sides are contaminated badly with oil/grease. I'm not sure if that alone is an excuse for not being able to hold against no load, but it can't help.

I'm pretty demoralized that a freshly rebuilt axle is leaking like that. I have brand new seals on both sides. My CUCV is abused and neglected and the brakes work great. The only thing I can think of is that I accidentally painted the spindle sealing surface during the rebuild, but I though I cleaned it all up far enough back for the seal. Any other ideas?

 

[rampage]

You may need a couple Speedi Sleeves.

http://www.pirate4x4.com/tech/billavista/SpeediSleeve/

 

[Mastiff]

You may need a couple Speedi Sleeves.

http://www.pirate4x4.com/tech/billavista/SpeediSleeve/

Funny, I just surfed up that same article. Thing is, my sealing surface looks night and day better than what he shows. Does the seal really ride as far back as where I have the pitting anyway?

 

[dremu]

Funny, I just surfed up that same article. Thing is, my sealing surface looks night and day better than what he shows. Does the seal really ride as far back as where I have the pitting anyway?

Eh, I'm not impressed by the speedi sleeves. Been there, leaked that.

I *am* impressed by the two-part seal, SKF 28554. (This is the one ORD sells; it's stock for later-model 14 bolts but fits older ones too.) I've used them on two axles with good results.

The inner half sits on your spindle and doesn't move, so it doesn't matter how bunged up the spindle is.

-- A

 

[Hogback Fabrication]

Eh, I'm not impressed by the speedi sleeves. Been there, leaked that.

I *am* impressed by the two-part seal, SKF 28554. (This is the one ORD sells; it's stock for later-model 14 bolts but fits older ones too.) I've used them on two axles with good results.

The inner half sits on your spindle and doesn't move, so it doesn't matter how bunged up the spindle is.

-- A

My experience as well, speedi sleeve (SUPER expensive) didn't work but the good seals did.

 

[Mastiff]

Do you guys think my spindles look boogered up enough that they should be leaking? Also, do you think oily shoes should prevent me from stopping the wheels (on stands) at idle, or is it likely something else is going on too? My past experience with oily pads was that they got extra grabby.

 

[1-ton]

Do you guys think my spindles look boogered up enough that they should be leaking? Also, do you think oily shoes should prevent me from stopping the wheels (on stands) at idle, or is it likely something else is going on too? My past experience with oily pads was that they got extra grabby.

Yes, your spindles definitely look "boogered up" enough to tear up a seal. If your shoes are completely soaked, then you will have to replace them, but if the oil did not soak in too deep...they can be cleaned up with sand-paper.

Also, when you adjust your brakes, make sure the park brake cable is backed off all the way, until the park brake arm completely seated at rest (with no tension pulling it forward). Then adjust both shoes to full lock, and then back off both sides 10-clicks. Adjusting your shoes to full lock will center the shoes to the drums. You can then adjust your parking brake cable for proper tension.

 

[Mastiff]

I'm going to try the "two part" seal and see how that works. Hopefully I can salvage these pads since they are new and I bought premium ones.

I keep hearing about people boiling pads/shoes to salvage them when they are oil soaked. Anyone here tried that? I don't think I have a big enough container anyway, but maybe I could dig something up at Goodwill or something.

 

[diesel4me]

I have soaked brake shoes in brake cleaner to remove gear oil that got on them from a leaky axle seal,I just bought 4 cans of it and sprayed them down good,then laid them lining side down in the cleaner overnight...

Years ago I saw a friend use gas to soak some,and he took them out of the pan after soaking them and lit them on fire to burn off all the gas...
Not sure I'd reccomend that method,but it worked for him--the shoes were recently installed and got soaked with gear oil shortly afterwards,so he was reluctant to just toss them and buy new ones again..he feared the shoes might just wear down right away or come apart,but they didnt--they were riveted linings,I dont know if I'd try this on bonded ones..

 

[dremu]

Oh, and if you didn't say/think of this already, before the new seals, I'd hit the mating surfaces on the spindle with an emery cloth. Hard to tell from pix, but run your fingers around and feel for rough/sharp spots.

-- A

 

[Mastiff]

Oh, and if you didn't say/think of this already, before the new seals, I'd hit the mating surfaces on the spindle with an emery cloth. Hard to tell from pix, but run your fingers around and feel for rough/sharp spots.

It's mysterious to me that it's leaking at all. The surface is pretty decent except for inside of where I think the seal runs. I accidentally painted the surface and spent a bit of time cleaning it up real nice. I'll clean it further back before the new seal though.