Are all of your trailer brakes working and how do you know?

[E_J_push_n_wind]

I posted this question in General RVing because I wanted this question to get as much exposure as possible, I think this forum gives it more exposure than it would get in towing or on the technical forum.

Anyhow,we all assume that all is well with our trailer brakes when we head out if we give the manual actuator a "throw" and we feel the trailer respond. After all, why would you think anything else?

Well, I just got back from a 3300 mile trip to WA state and back and if I wouldn't have had a Fluke Ti100 thermal imager with me. I would have been in the dark.

As it turns out, I borrowed one from work (wonderful they let us do that) to take with me on the trip for the purpose of "scanning" the wheels and what not just to keep everything in check. I found out two things on the trip amongst other things. 1) I had one brake dragging and eventually one brake failed, both on the same side. Now, the brake that was dragging I know was dragging because it was running hotter that the rest when I stopped for gas and got a temp reading on the wheel assembly. It was reading upwards of 196 degrees and the other three were reading at about 160 degrees. I crawled under the TT and backed off on the adjuster a few clicks. It got me to thinking, this is the same wheel I had a blowout on back in June. Could have been the wheel just got to hot and caused the tire to fail. The Jury is still out on that one because I have no way to confirm that but it stands to reason that it could have been the reason for the tire failure. Especially since I had two failures on the same wheel inside of 6 months.

Secondly, the brake on the same side on the front axle failed. Again I know this because after reading at each stop for gas and all of the brakes running about the same temp of about 160 + or - a few degrees, that one in particualr read 86 degrees upon stopping and reading it. With a thermal immager you can see what is going on. The perimeter of the drum would of course show the hotest (bright red) and you could see the rest of the of the wheel assembly and their various temperatures as well. The imager discriminates very well as well so there is no confusing what is going on.

As it turns out, after getting the TT out of the shop and talking with the service manager, I had a magnet failure. The wire came loose internally. I asked him if it looked like the magnet had failed from day one and there was no ware on the brakes or if it looked like they were working and at some point it failed. He said it looked like it was working and at some point failed.

So, I pose the question. How would you know if you had a magnet failure or some other brake failure (electric brakes) short of all four not engaging? When I would brake, everything felt normal. No pull to one side or the other. I had effectively 75% braking which aint bad, but it ain't great either!

[jmtandem]

It's really a fun/neat tool to have along but as jmtandem stated it is more than one practically needs. It is really pricy and if I would have had to buy it, it wouldn’t have come along. I’m glad it was available. If ever I had to buy one, it would probably be one of those Harbor Freight ones that was mentioned.

I found the inexpensive Harbor Freight infrared temp probe to be within two degrees accuracy or so. I think for $39 they are all that is really needed to determine if you are going to have a brake or hub problem. I have even tested it against my body temp and it was right on. For trailering they are all that is really needed. Not saying that fancy high tech stuff is not fun to play with as it certainly can be.

[E_J_push_n_wind]

Just going by what he said, I didn't actually see it afterward. As far as the brakes, I only began to read them because of the 196 degree brake I saw through the wheel when scanning. It was "redder" on the imager than the rest and that is what got my attention. Again, my initial reading was looking at the hubs only but I could not ignore what I saw through the imager considering right after braking one brake only was 40 degrees hotter than the other three. Only after that did I begin to look at the brakes to makes sure my loosening the adjuster made a difference. Eventually it did after several small adjustments. It was the same noticing the brake that failed. I should have seen "red" using the imager on the perimeter of the drum after coming to a stop. It looked as cool as a pop cicle so that too got my attention.

After this experience, I'm gunshy or even paranoid now. Not that it was a life threatening experience or that the trailer exploded or anything like that but now I feel like I have to have something that will give me an idea of what is going on with the wheel hubs/brakes. I even shot the temp of the differential just to get an idea of what was going on with it. I shot everything that generated heat including the radiator, condensor actually as that is what is up front.

It's really a fun/neat tool to have along but as jmtandem stated it is more than one practically needs. It is really pricy and if I would have had to buy it, it wouldn’t have come along. I’m glad it was available. If ever I had to buy one, it would probably be one of those Harbor Freight ones that was mentioned.

[Vulcaneer]

Not likely your wire broke inside of the magnet after a while. More likely the wire within the drum rubbed through on the linkage somewhere. Then it shorted or broke. That is what can happen over time.

If your drum temps are running about 86 degrees with no brakes operational and are running at 160 degrees with brakes operational, then your brakes are not adjusted properly. But then again, you should not be checking your drum temps right after you use our brakes when pulling into a rest area. let them cool for a few minutes. Same reason you don't check tire temps after running. Of course they're going to be higher.

[E_J_push_n_wind]

Vulcaneer wrote:
OK E&J, I do think your wheel hub temps seem to be on the too high side. I don't like to see any temps higher than 140 degrees. If you cannot hold your hand comfortably on the hubs for 15 seconds, the hub is too hot. And if too hot the grease may start to thin and could run past a seal. Maybe your bearings are a bit too tight?

I mostly tow my trailer in Florida and at highway speeds. Wheels operating in the sunshine may get close to 140 sometimes. In the shade they run cooler.

Most newer brake controllers will advise if there is a disconnect or an electrical problem with any one brake. They will give a warning message.

Mr. Vulcaneer, I agree with you. Those would be high for hub temps, I'm talking about the perimeter of the brake drum after coming to a complete stop off of the highway and pulling right into a gas station. I mentioned earlier that when I had the failure on the one brake, the drum assembly was running about 86 degrees. I thought 160 degrees was not at all that hot for brakes. My disc rotors on my car run much hotter than that just driving around town without the TT.

[E_J_push_n_wind]

fj12ryder wrote:

jmtandem wrote:

So are you suggesting that everyone travel with a thermal imaging device? That may be a good idea, but loses points on practicality.

For under $50 everybody can travel with a Harbor Frieght infrared temp probe. It is small, practical, and works. It can save a roadside repair by detecting a bearing problem as well as brakes that are working or not. A thermal imaging device is wonderful but for most trailering applications is probably more than needed. This has been an excellent thread and my read of the OP's concern is that however we do it the brakes should be checked to be certain they are working. Thermal imaging is only one way to do it.

I have a non-contact infrared temperature gauge and use it pretty regularly.

The point I was trying to make was that the OP kind of pooh-poohed everyone's suggestions on how they check the functioning of their brakes, and seemed to suggest that unless they were using a thermal imaging device they were not doing enough.

"I can say this, minus the thermal imager I used from work. I would have continued business as usual thinking everything was fine."

I'm not Pooing on anybody's idea, just wondering about the practicality of some of the ideas is all. Keep in mind we are on the road traveling, no gravel roads to mention, no jacks except to change a flat if necessary. In this particaular case, I was traveling from So Cal to WA state and back, just interstate and surface streets.

I keep asking the question though, how would you know? Where you quoted me at the bottom of your post is an absolute fact. Okay, I used an imager from work, they have retired 3M heat tracers as well that I could have brought, this one just happens to be much nicer. No, it is not the only way to check your brakes. I didn't actually bring it for my brakes but rather by the suggestion of many right here on the forum for checking my wheel hubs. It just happened to be an added benefit that I could check the brakes with it. If I wouldn't have seen the abnormally high temp on the one brake I can promise you I wouldn't have bothered checking the others. I can say this too, if I would have used the 3M heat tracer I would have overlooked the brakes as again, I really didn't even consider the brakes to be a problem. It would have never entered my mind because when I step on the pedal I feel the tug on the back of the car! In my mind, everything is well as far as the brakes are concerned. I don't think I'm being unreasonable. I'm just pointing something out that I think many, myself included ever gave a thought to.

restlesswind wrote:
I check for current draw right after hooking up.I apply full braking using the manual mode,then do the same using the brake pedal.I also check the reading at a stop sign,once in a while,especialy if the braking seems to feel "not quite right".
After towing this trailer over 70K miles,it's pretty easy to tell if the brakes feel OK or not.I also use the "ray gun" at just about every rest stop.

I’ll have to check this out. I’ve seen the numbers “flash” when I do the initial brake check but I never really paid any attention to them. Again, brakes “feel” right, what could be wrong? Right! At least that WAS my disposition anyway, how wrong I was! I’ll start paying a little more attention to those numbers and what they mean. Believe me. I thought I knew, I’m learning and I think this is really what I’m trying to stress. If one doesn’t know this about their brake controller but everything “feels” right when you brake, I’ll keep asking. How can you know?

I wanna say this too. Throw everything away I said about the thermal imager. I’m on my way to WA and the same thing happens. Remember, when I left San Diego I had brakes on all four wheels albeit one was working harder than the others. At what point do I discover I have a problem with one of my brakes, and how do I discover it? Some of you have a lot of miles and years behind you and perhaps have ways of discovering something like this. Again, the brake controller idea is a great idea and I will employ it but it has one small drawback. How do you discover which wheel has a failure? You know you have a failure and that is half the battle but now discovering which wheel is the problem. (If you are at home and have tools like restlesswind, you can use the clamp-on-ammeter as I don't think many carry these tools with them just like a heat tracer or thermal imager) I suppose that is not that big a deal though because once you discover it, you do the same thing I did. You take it to the shop and have them fix it. I will say this though, I was able to tell him exactly which wheel had the failure. I wonder if he had to trouble shoot each wheel till he found it if that would have uped the ante? This is not to start another debate about where you bought your RV and getting it serviced. I used an independent if one must know.

Okay, last thing. I asked the service manager how common this problem was. Mine being an open inside the magnet. His response was, he gets one like this about 1 in 100. It is not a very common occurrence but it does happen. My concern was, which one is next and do I need to do them all?

[Vulcaneer]

OK E&J, I do think your wheel hub temps seem to be on the too high side. I don't like to see any temps higher than 140 degrees. If you cannot hold your hand comfortably on the hubs for 15 seconds, the hub is too hot. And if too hot the grease may start to thin and could run past a seal. Maybe your bearings are a bit too tight?

I mostly tow my trailer in Florida and at highway speeds. Wheels operating in the sunshine may get close to 140 sometimes. In the shade they run cooler.

Most newer brake controllers will advise if there is a disconnect or an electrical problem with any one brake. They will give a warning message.

[restlesswind]

E&J push'n wind wrote:

jmtandem wrote:
This is a good thread. This is also why I use a infrared temp thermometer to check hubs and brakes. All mine have been within 10 degrees of each other. I am a little surprised of the temps you consider normal as after towing more than an hour my temps are more like 115-120 degrees and that is with minimal braking and properly adjusted brakes.

Compared to your temps mine do look high. The only thing perhaps is the accuracy of your heat tracer or pyrometer, it could be reading low maybe or not. How do you know its accuracy? Ours is checked anually against a blackbody which is calibrated anually to the National Bureau of Standards for accuracy and certified for accuracy. Our thermal imager is accurate to within 2 degrees on either side of what the Blackbody reads.

restlesswind wrote:
I don't know about other brake controllers,but mine give me an amperage readout.There should be right at 3 amps current draw per magnet,with 12-13 amps when braking when all 4 are working.

For a while mine were only showing 9 amps when braking.With a little trouble shooting using a clamp-on amp meter I was able to find which magnet was not doing its share of work.Though the braking seemed to be fine.
There was a bad wire conection.I redid the connection and all is now well.

If I'm not mistaken, wouldn't the current draw depend on how hard you are braking? Mine shows current draw as well but it is never constant, it varies with brake input. How could you know based on that how much each magnet is drawing? Little input, little draw and again, not constant and more input, more current draw. Am I missing something?

I check for current draw right after hooking up.I apply full braking using the manual mode,then do the same using the brake pedal.I also check the reading at a stop sign,once in a while,especialy if the braking seems to feel "not quite right".
After towing this trailer over 70K miles,it's pretty easy to tell if the brakes feel OK or not.I also use the "ray gun" at just about every rest stop.

[jake2250]

RCMAN46 wrote:
Every time I stop for fuel or food I touch each bearing hub. They should all be about the same temperature and unless you had recently did some heavy braking should not be hot to the touch.

Yeah, thats about right,before I get going again,give truck and trailer a good visual check touch tires and hubs with the back of my hand to get a feel of one thats different, also doesn't hurt to make sure steps are stowed and awning is ok..

[RCMAN46]

Every time I stop for fuel or food I touch each bearing hub. They should all be about the same temperature and unless you had recently did some heavy braking should not be hot to the touch.

[fj12ryder]

jmtandem wrote:

So are you suggesting that everyone travel with a thermal imaging device? That may be a good idea, but loses points on practicality.

For under $50 everybody can travel with a Harbor Frieght infrared temp probe. It is small, practical, and works. It can save a roadside repair by detecting a bearing problem as well as brakes that are working or not. A thermal imaging device is wonderful but for most trailering applications is probably more than needed. This has been an excellent thread and my read of the OP's concern is that however we do it the brakes should be checked to be certain they are working. Thermal imaging is only one way to do it.

I have a non-contact infrared temperature gauge and use it pretty regularly.

The point I was trying to make was that the OP kind of pooh-poohed everyone's suggestions on how they check the functioning of their brakes, and seemed to suggest that unless they were using a thermal imaging device they were not doing enough.

"I can say this, minus the thermal imager I used from work. I would have continued business as usual thinking everything was fine."

[jake2250]

I store my trailer at a secured lot near home (within 5 miles). Lot is gravel covered dirt. After I hook up trailer I pull forward to get out of the slot.
I stop and do a light check,make sure hitch and wiring look good, check wheels and tires,check outside compartments and awning,go back in the trailer and make sure doors are shut (refrigerator,bathroom,cabinets), then I get back in drivers seat adjust mirrors.
I then pull forward and get to at least 10mph and activate brake control to lock up trailer tires, I check in my mirrors that tires have locked up,,then accelerate again up to 10mph and stand on the brake pedal to lock up trailer brakes.
I then get out and look at the trailer to make sure I have skid marks in the gravel from all four tires. I then go around and make one more final "walk around" visual check before I hit the road.

[jmtandem]

So are you suggesting that everyone travel with a thermal imaging device? That may be a good idea, but loses points on practicality.

For under $50 everybody can travel with a Harbor Frieght infrared temp probe. It is small, practical, and works. It can save a roadside repair by detecting a bearing problem as well as brakes that are working or not. A thermal imaging device is wonderful but for most trailering applications is probably more than needed. This has been an excellent thread and my read of the OP's concern is that however we do it the brakes should be checked to be certain they are working. Thermal imaging is only one way to do it.

[fj12ryder]

So are you suggesting that everyone travel with a thermal imaging device? That may be a good idea, but loses points on practicality.

[E_J_push_n_wind]

Ya know, I wish I would have used the camera feature of the imager so y'all could see what I saw. I literally put the "cross hair" on the perimeter of the drum as that was the hotest part showing. I have aluminum "mag" wheels and the spokes have space enough through them so that the drums are very well exposed. 160 degrees didn't seem all that "hot" to me at all especially considering when the one brake failed to work. With no heat to mention it still was 85 or so degrees. I have to believe that with brakes applied, that the drums would warm up more than 15 to 25 degrees.

As far as annual inspections, I check my brakes regularly and adjust as needed. However, even with an annual or regular "checkup". My brake failed while I was traveling and again I ask, how would I have known. How can you know short of jacking up the trailer or each wheel while on the trip and pulling the brake away switch and checking each wheel? I mean really, all due respect, who is gonna do that while traveling? Or even find the gravel road, which is a good idea but it may be a little out of the way. Just trying to be practicle while in travel, short of some sort of temperature reading device, how can one know they have a failing brake?

I can say this, minus the thermal imager I used from work. I would have continued business as usual thinking everything was fine. I would have come home, emptied the TT cleaned it up and got it ready for the next trip whenever that may be. The next trip I would have loaded it up checked the brakes for adjustment as needed hooked up and pulled away, gave the brake controller a manual slide and felt the response from the trailer and been on my way thinking all four wheel were braking fine.

I wonder how many are on the road right now without a clue that they may have a bad magnet or even two for that matter thinking everything is fine because they feel the trailer tug on the rear of their TV when engaging the brakes? I can promise you, I could'a and probably would'a been that guy!