Rear Brake Randomly Dragging

[BrianX128]

My 85 F350 on the way to work today right towards the end of my commute I smelled hot brakes. Got to work in the pouring rain and my rear drivers side brake must have been dragging, rim was hot but not melt your fingers hot and it was steaming from the rain. I didn't have my e-brake on overnight before I left but it was super damp, brake pedal feels fine and truck stopped normally, I didn't even notice anything from the cab until I was parking and smelled it.

I'm guessing I can back the brake off some when I get home, but I'm curious if there is anything I can do with no tools before I leave today to try and free it up some. Floor it in reverse and slam on the brakes? Put e-brake on and force it in reverse? I'm not sure if these do any of the auto adjusting in reverse or not. It made it there so I'm guessing it will make it home, just not trying to melt things entirely until I can pop the tire off and see what it did.

 

[79jasper]

Reversing and stomping the brakes is literally the process to make the auto adjust, so no, don't do that.
Personally I would pull the drum to see what's going on. All you need to back it off is 2 screw drivers.

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[Ky85]

If its dragging the auto adjust tightens it up, which sounds like you already have a problem with.

Hard to say without a look inside, at work you could try to check for leaks in brake system, fluid level.

 

[BrianX128]

Weird. I just drove it around the parking lot, I could feel a small drag so I pushed the ebrake the whole way down and popped it back up a good 5 or 6 times and coasted down the hill and reversed back up it, I could feel the tension slowly leaving as I did this. Fluid is full, nothing leaking by this tire or anything.

The only thing I can think of is the last thing I did in this truck was haul a lot of gravel and had it sitting on a hill with the ebrake on in gear. I'm wondering if it coasted backwards enough against the ebrake it over adjusted it tighter and it was locked with the moisture from all the rain last night? I guess I'll find out when I drive home.. I wouldn't think it would coast down a not very steep parking lot like it does now, and I couldn't get the rim even warm with all the back and forth I did across the lot.

 

[franklin2]

Weird. I just drove it around the parking lot, I could feel a small drag so I pushed the ebrake the whole way down and popped it back up a good 5 or 6 times and coasted down the hill and reversed back up it, I could feel the tension slowly leaving as I did this. Fluid is full, nothing leaking by this tire or anything.

The only thing I can think of is the last thing I did in this truck was haul a lot of gravel and had it sitting on a hill with the ebrake on in gear. I'm wondering if it coasted backwards enough against the ebrake it over adjusted it tighter and it was locked with the moisture from all the rain last night? I guess I'll find out when I drive home.. I wouldn't think it would coast down a not very steep parking lot like it does now, and I couldn't get the rim even warm with all the back and forth I did across the lot.

You can keep thinking positive thoughts, but it usually doesn't work.

If you have a sticking brake cable it's easy to diagnose. Get someone to operate the e-brake while you are sitting underneath the driver's side watching the cables where they are hooked to the spreader bar. As the e-brake is pushed and then released, both cables should follow the motion exactly with no delay. If one of them is not really moving at all, you can take some vise grips and clamp the cable, and then smack the side of the vise grips forward to pull the cable back out of the sheath. If it moves a lot, then you know the cable is sticking, and don't use the parking brake again till you replace it.

If the cables seem to be working ok, then you have a rusted and stuck wheel cylinder on that side. Probably time to do both sides.

I have never had a auto adjuster "over adjust". Their failure mode is not working at all.

 

[Cubey]

My understanding is that using the parking brake also self adjusts, but that would be tighter.

Maybe your parking brake isn't fully letting go ne one side sometimes. It's cable drive after all, and cables get dry and don't like to work as well.

 

[BrianX128]

I honestly never use the ebrake either so it seems very coincidental for it to happen right after it was used on a steep hill. I'm gonna drive half way home and pull over and see what it's like, I only need to get 18 miles. I don't want to ruin something for an easy fix but I absolutely don't have spare time today of all days to have someone get me to get tools etc..

 

[kbenz]

You can keep thinking positive thoughts, but it usually doesn't work.

If you have a sticking brake cable it's easy to diagnose. Get someone to operate the e-brake while you are sitting underneath the driver's side watching the cables where they are hooked to the spreader bar. As the e-brake is pushed and then released, both cables should follow the motion exactly with no delay. If one of them is not really moving at all, you can take some vise grips and clamp the cable, and then smack the side of the vise grips forward to pull the cable back out of the sheath. If it moves a lot, then you know the cable is sticking, and don't use the parking brake again till you replace it.

If the cables seem to be working ok, then you have a rusted and stuck wheel cylinder on that side. Probably time to do both sides.

I have never had a auto adjuster "over adjust". Their failure mode is not working at all.

Yep. I just went through this

 

[BrianX128]

So oddly enough it was fine on my drive home. I think that side of the cable must be binding but I can't figure out where. Any special spot to blast with pb blaster? I don't see any stand out rusty spots on it.

 

[The_Josh_Bear]

Based on the part where you never use the parking brake till once just recently, and then it got better and better after using it and popping it free, I'd say it was sticking as @franklin2 mentioned and then using it a few times in the parking lot freed the movement up and it went back to normal-ish. I also agree with pulling the wheel but when you don't have time you don't have time. If it's fine now then pull the wheel over the weekend or something.

All that said I would use the parking brake, it's a good, safe habit to get into. Maybe you live in some very flat area. I parked my 88 4.9L 5-speed once on a hill with a poorly working parking brake and the next morning it was at the bottom of the hill, still in gear!!! Thank God no cars or people were behind it. It must have rolled down the hill backwards one slow compression stroke at a time.

 

[Cubey]

It could also be weak return springs down underneath for the cables, especially if it was parked a long time with the parking brake set. If you want to lube the cables better, get a motorcycle cable lube tool. It clamps on and forces it down inside the sheathing when you spray into it. They don't cost too much online, about $10-20.

 

[franklin2]

I have never been able to lube the cables and make them reliable. If you never use the cables, and the one time you did you had a problem, I would not use them again till you replace them. I would get them to release and don't touch them again. You may need to use the vise grip trick to get them to release fully.

 

[BrianX128]

Honestly everywhere I normally park at work / at home is flat, I always throw the truck in low range when I park on hills to help out but toss the e-brake on just because when I'm doing gravel or mulch around my yard on hills, I don't do that very often but I've done it before with no issues. I will say something doesn't seem right about my setup on this truck but it's the only bullnose I have. My petal goes down only 2 clicks, 3 if I really push and feels super tight. My brick noses all go about 3x the travel distance on the petal and it doesn't feel tight until it's almost on the floor. I guess it might be time to replace it unless they are just different feeling?

 

[79jasper]

Wouldn't low range make it easier to overcome the compression?

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[franklin2]

Honestly everywhere I normally park at work / at home is flat, I always throw the truck in low range when I park on hills to help out but toss the e-brake on just because when I'm doing gravel or mulch around my yard on hills, I don't do that very often but I've done it before with no issues. I will say something doesn't seem right about my setup on this truck but it's the only bullnose I have. My petal goes down only 2 clicks, 3 if I really push and feels super tight. My brick noses all go about 3x the travel distance on the petal and it doesn't feel tight until it's almost on the floor. I guess it might be time to replace it unless they are just different feeling?

Sounds like stuck cables. Your foot is a lot stronger than the spring that releases the cable. So you bear down on it and overcome the rust, but then it's not strong enough to move back by itself. Thus the hammer/vise grip trick to force the cable back toward the front to release.

Keep and eye on the temp of the rear drums. They can be slightly activated and not cause too much of a problem, but your fuel mileage will suffer. They are a pain to replace, so if you can get them driven back forward and then not touch the parking brake, you will be ok till you can get to it.