lock-up brakes from overnight dampness...

[safari25-05]

I was just wondering if anyone else out there has this problem. After traveling for a day, and then camping overnight when I go to leave the campground in the morning, when I tap the brakes the trailer wheels lock up. Till all the dampness gets out of the brakes, then their ok. I want to check and make sure all 4 of my brakes are working and working evenly. The brake shoes that are provided by the trailer manufacturers seem to be quite conventional and nothing special. Does anyone know if there is some after market brake shoes available, of a better material, I don't really understand why the brakes lock up like that, my trucks don't lock up when their wet. Any input on this would be appreciated....

[TomW]

Grease on the shoes (leaking grease seals) can cause brakes to grab. Although your Airstream is relatively new, the shoes should be inspected first (pull the drums) before rounding up potential replacements.

Tom

[boatdoc]

Originally Posted by safari25-05

I was just wondering if anyone else out there has this problem. After traveling for a day, and then camping overnight when I go to leave the campground in the morning, when I tap the brakes the trailer wheels lock up. Till all the dampness gets out of the brakes, then their ok. I want to check and make sure all 4 of my brakes are working and working evenly. The brake shoes that are provided by the trailer manufacturers seem to be quite conventional and nothing special. Does anyone know if there is some after market brake shoes available, of a better material, I don't really understand why the brakes lock up like that, my trucks don't lock up when their wet. Any input on this would be appreciated....

Hi Safari25-05; Very few of us actually realize why brakes lock up over night, and the reason is quite simple. Moisture drawn from the ground is the answer. The brake shoes and the drums are very hot after tow. When the trailers is parked on unsealed surface the heat from the brakes escaping up creates air venturi in that area, thus drawing up any moisture around tires from the ground.
The ground air, of much lower temperature is drawn up by the created venturi affect, which collides with very hot brakes, resulting in deposit of moisture on the drums. From here you should guess what happens. Placing the wheels on heavy 4x8' tarps for double axle will greatly reduce axle and it's component corrosion. We have made experiments with boat trailers, and got a big surprising results. Trailers parked on grass have had heavy corroded drums in two weeks. Those parked on gravel did somewhat better. Concrete was better yet, but vapor barrier created by heavy tarp showed only light oxidation after six months. Checking for grease on the drums is a good idea as well. Thanks, "Boatdoc"

[ticki2]

Metalic shoe liners can also cause this problem.

[CanoeStream]

What sort of brake controller are you using? I find that my Prodigy + drum brakes grab when I'm starting out. Braking that occurs in the first couple miles starting out seems to make things smoother. I keep thinking about getting disk brakes... Guess I never looked at this grabbing as a moisture problem. Condensation occurs when an object is colder than a surrounding humid environment, not warmer. I'd think you'd see moisture on the belly wrap if your trailer was causing a lot of condensation.

A rather different consideration is calibration of your brake controller. It might be set too strong so that a disproportionate amount of the stopping is being done by your trailer brakes. I know the Prodigy instructions are quite clear how to do this.

[troubleskeep]

My trucks do this as well without the trailer attached, and only after rainfall or heavy dew. The oldest truck is only 6 years old, the newest is only about 1 year old. I'm more inclined to agree with BOATDOC. I'm a bit curious though with the boat trailer experiment. Were there boats on the trailers? If not, wouldn't rainfall or dew accumulate on the plastic and worsen the effects?

[Inland RV Center, In]

Originally Posted by safari25-05

I was just wondering if anyone else out there has this problem. After traveling for a day, and then camping overnight when I go to leave the campground in the morning, when I tap the brakes the trailer wheels lock up. Till all the dampness gets out of the brakes, then their ok. I want to check and make sure all 4 of my brakes are working and working evenly. The brake shoes that are provided by the trailer manufacturers seem to be quite conventional and nothing special. Does anyone know if there is some after market brake shoes available, of a better material, I don't really understand why the brakes lock up like that, my trucks don't lock up when their wet. Any input on this would be appreciated....

What you experienced is somewhat normal.

When you use the trailer brakes, you polished the drum surface to almost a mirror finish.

When the brakes are not used, and high humidity is in the air, a film of rust will very quickly show on the surface of the drums.

That rust increases the metal to shoe friction dramatically.

Therefore when you used the trailer brakes again, the grabbing is caused by that rusted surface. A few applications of the trailer brakes will dispense with that problem.

This does not happen often, but it can and does happen.

Not to worry, just be prepared.

Andy

[john hd]

mine does it pretty regularly as andy noted, i just back off the controller a bit for the first 2 or 3 stops.

i have confirmed this by my annual demounting of the brakes and bearings. and i have noticed the light coating of rust.

john

[boatdoc]

Originally Posted by troubleskeep

My trucks do this as well without the trailer attached, and only after rainfall or heavy dew. The oldest truck is only 6 years old, the newest is only about 1 year old. I'm more inclined to agree with BOATDOC. I'm a bit curious though with the boat trailer experiment. Were there boats on the trailers? If not, wouldn't rainfall or dew accumulate on the plastic and worsen the effects?

Hi troubleskeep; The experiments were done for one purpose only. We have aimed to determine if unsealed surface such as gravel or grassy area can adversely speed up the rusting process. All tests were done with brand new brakes installed. Trailers parked on grass, have showed most corrosion after two weeks. Trailers parked on gravel were somewhat less corroded. Those parked on heavy tarp, hardly showed any oxidation. All trailers were parked side by side in the same period of time, and none had boats on it. All trailers had hydraulic brakes. Interesting find on the second experiment, was that one with partially applied actuator which caused the shoes to be touching the drum, were stuck after one week. Despite the fact that when the drums are hot the condensation is burned off, but when the temps differ slightly as the brakes cool off, the condensation was plainly visible on trailer brake componnents parked on grass. In the end, it is anyones choice but my trailer sits on two 4x8' strips of heavy tarp and it is doing fine. Thanks, "Boatdoc"

[Action]

You can notice the same on a car that has disc brakes and an open wheel. (So you can see the rotors) Spray the rotors after a drive in the car. (as in spraying from a car wash) the rotors will take a surface rust rapidly. Usually no a concern after a couple of brake applications. The issue would be if it was stored that way over a very long period (year or so) of time. I have seen friction material rusted to a drum, so no forward or rear ward movement could occur.

>>>>>>>>>>>Action

[garry]

Most controllers have a manual way to apply the brakes.
I use this feature to "lightly" apply the brakes for the first hundred feet or so to dry the pads.

Garry

[Loren]

safari25-05,

As others have said, what you experience is normal. Allow for this phenomenon when you start towing for the day and don't worry about it.

Loren

[overlander63]

Again, this is normal. I use the trailer brakes alone for the first 3-4 stops within the campground, and by the time I get on the streeet they are dried out, warmed up, and ready to work as intended for the rest of the day.

[Mike Lewis]

Something that hasn't been mentioned is adjustment. Drum brakes are self energizing and any excess clearence between shoes and drums while not a cause, will increase grabbing what ever the cause.---pieman