Hello to all! I've been lurking and searching in the background for a while but now it's time to post.

I have a 2006 F250 2x4 SWR with 51500 miles. Early last month after I returned home from a camping trip I could smell that familar burning brake smell but there was no smoke and I couldn't determine which wheel it was coming from. Thought maybe I left the e-brake on while backing the camper up in the yard. A months worth of daliy driving goes by without any problems. Last week were headed off on another camping trip and here comes that smell again. I pull over to find smoke pouring off my back right wheel. I immediately think its a bearing because it only happenes when Ive got some weight on the hitch. I unhook the camper right there on the side of the road, limped my Ford home, and then had to borrow a friends Nissan Titan to get my camper the rest of the way to the beach. Yeah I caught some hell for that.

When I got back from the beach I dug into it and found the right rear brake pads were severly cooked but their wear was even. The sliders bolts were not seized up but not sure if the piston was stuck. I went ahead and replaced both rear calipers with rebuilt ones, installed new pads, turned the rotors, and bled the brakes. By the way the e-brake pads looked good and actuate properly so I can at least rule them out.

So far everything seems to be okay. After each commute I feel each wheel for heat and they all feel the same. A few times I even got under and felt for heat on the axle behind the backing plate close to where the bearings are located but there is no temperature difference between the left and right side. I'm assuming if it was a bearing it would still generate heat even without the weight of the camper or at least make some kind of annoying sound, right?

One fact I can't ignore is the two times it's happened I had the camper hooked up to the truck. Maybe this was just coincidence. Is there any way (I'm reaching way out there on this one) the factory installed trailer brake controller could cause a braking issue on the truck? I like to know the exact reason a problem happens before I throw parts at it. Not to mention we have another camping trip planned at the end of the month.

 

Typically a caliper issue when not slides, but could also be a brake hose.

Anything upstream (controller screwing with ABS) would cause the issue to both rear axle brakes. It may be more prone to occur with the camper as the energy dissipated would be much higher. With a higher temperature increase due to the weight the friction material would expand wider and cause more of a brake application.

 

I get what your saying fmtrvt. The bigger load on the truck brakes (with camper hooked up) will cause them to heat up more and expand.

I always assumed the brakes on the camper were self adjusting but after reading up on them last night I found out they are not. The manufacturer suggests manually adjusting them every 3000 miles and my camper probably has over double that. Looks like I'll be checking them out and ensuring the controller is adjusted properly.

 

If you pulled the pads on that side and they were evenly worn, I wouldn't suspect a caliper problem at this point. If the slides or piston were seized up, one pad would be worn much more than the other typically. Your description would point me possibly at the soft line for that caliper. If it's slightly obstructed or there's a problem with the line that won't allow the pressure to release, it would give you the symptoms you were describing.

Gives you something to look at anyways if you continue to have issues.

 

I would be expecting a hose replacement shortly, too.

Even with a perfect trailer brake there is still a higher workload done by the vehicle.

Trailer brakes historically never do their balance of the work even when properly adjusted, and the situation gets worse with the pulling vehicle has disc brakes (front only or 4 wheel). One common adjustment of the controller is supposed to be that both the pulling vehicle and trailer skid tires at the same points. But a disc brake has a linear output to hydraulic pressure, whereas duo-servo drum brakes have an increasing output due to the self-energizing effect. What this means is that you can adjust the trailer’s brake to skid at the same deceleration rate as the pulling vehicle, but during normal operation the pulling vehicle will do a higher share of the work. With a disc/drum pulling vehicle the situation is even worse for the front disc brake.

While this graph was for a disc/drum brake presentation, the respective outputs between a disc/disc pull vehicle and a duo-servo drum brake can still apply. A sophisticated brake controller will try to flatten the trailer drum brake to be more linear like the pulling vehicle, but it’s never precise.



I’ll include a graph of how the historic in-line proportioning valve was utilized to compensate between the disc and drum brake, but it was never a perfect application.

 

i too would suspect a problem with the soft brake line for that wheel. I havn't been under our SD for quite a while now, but i suspect there is some kind of ruber hose that feeds fluid that that wheel only. That's where i'd start.

typically, you can feel this when you bleed them. there should be almost zero resistance with the bleeder screw open. when i've had a soft line collapse, the brake pedal has a fair amount of resistance even with the bleeder screw open. That being said, it does not take much of a resistance to cause a problem.

any blockage in the hose will make it difficult for the caliper to push the fluid back to the master when the pedal is released.

my guess is that when you have the camper on the hitch, you are driving more miles than you typically do, and you use more brake pedal than you would in daily driving. (as supported by the post on hydraulic pressures above).

the combination of the two means that the caliper has more overall hydraulic pressure to overcome when the pedal is released, and you are driving longer building more heat in the process.

then it is a self building problem from there.... more heat=>more drag=>more heat=>more drag

sorry for being long winded ..... check your brake hoses, that's where i'd start.

 

You guys are awesome!

I double checked the thickness of all 4 of the rear pads with a dial micrometer and they are all within .065" of each other; left, right, top, bottom, inside, and outside. I know replacing both rear calipers was a shotgun troubleshooting technique but there are plenty of threads on this forum, as well as others, that directed me down that path. I am an Industrial Service Tech by trade and at work we call that being stuck in a wormhole, there is no escape.

I'll probably go ahead and replace the the 2 rear soft brake lines just to be on the safe side.

 

You did a good job in catching that early with the pads that close, and I certainly understand why you did the caliper replacement. Those little hoses that don't move around have had their share of issues, surprisingly since they don't move. And maybe that's the issue if the rubber does need to exercise to release the sustaining oils like tires do (dry rot).

And yes, FTE seems to have a high amount of weird brake theories.

 

I think I'm having this same problem after I drive 50+ miles at a time

 

me too...i think it is the right rear tire too...i drive the same 35 miles to work everyday....sometimes unloaded...most of the time with about 10k on the trailer and i can smell mine only with the trailer...has been like that for about 3 months...i've been lazy...and i don't wanna be in the heat on my only day off when i am in it all day at work

 

When you have one rear brake that is heating up .....

The first thing to do is crawl behind the rear axle and loosen the slide pin bolts on that side by about 1/4", then check if the slide pins will move side to side. If not, you have frozen slide pins. If they do move easily, then it's time to pull the caliper and see if the pads are not sliding in the brackets and how difficult it is to push the pistons back into the caliper.

If it takes a little more then just over finger pressure to push the pistons in then it's not the caliper pistons and I would replace the hose as it's cheap enough. If the pistons won't go back in relatively easy, crack open the bleeder and see if that helps. If it helps, then you have a bad hose. If it doesn't help, time for new caliper.

 

One thing that barely got mentioned in this thread and something I can share my experience with - that @#$% emergency brake. The e-brake backing plates on my SD rotted, allowing e-brake shoes to drag just enough to smell.

OK, my thread - https://www.ford-trucks.com/forums/1...s-06-f350.html - and yes, I did get that 'burning brake smell. First, it was after a fairly long run, then it got shorter and shorter between those smelly brakes.

That repair got expensive, but even worse - time consuming and in Jan/Feb - which luckily this year was snowless and with the temps in the high 20's, low thirties - shirtless weather for winter in my area

As far as parts - Rock Auto had everything and great delivery. One part - that inner hub seal, National - it's identical in every dimension as well as visually to the Motorcraft and a LOT less expensive - that was a screw up find where I had to repull the hub

 

That is funny. I had just registered with Rock Auto and was having to check my email for my initial password when I noticed an email update from FTE saying someone else had responded to this thread.

Rock Auto is way cheaper. I'm glad my local AP store was out of stock of the brake lines because I would have paid twice as much. I can spare a few days waiting on the shipping.

 

HI Jack
You sure are a wealth of 'free' information.

I addressed this and stopping issues in another post.

I have the same issue - suspected RR lock up or dragging pads. I just replaced the rear pads with the OEM OE pads PN you recommended. Pads I removed were NAPA top of line. About 2000 miles - many smoking hot stops. Really smelled burned, discolored.
Caliper appears OK and pistons slide OK
This truck sits more then it is used. Only 44K on it. I suspect since it sits these line go bad due to non-use.

I am replacing BOTH the rear rubber brake lines.

Thanks for being here.
RR

 

My F250 sits a lot too. I also own a 1999 F150 and I swap daily driving duties between it and the F250 on average about every 2 weeks. On top of that I live only 8 miles from my work so I don't put a lot of miles on either of them. I would have had a lot fewer than 51000 miles on my F250 but I've had to make a lot of trips from SC to KY in the last year and a half for family reasons. I chose to use my F250 on these trips because I considered it to be the "more reliable vehicle" since it was newer .