How will brakes behave with wrong "type" setting

[toolman.dustin]

I've been having "issues" with my trailer electric brakes grabbing and the front tires sliding. My 2016 Tundra has an integrated progressive controller.

I just discovered the Tundra brake controller "type" was set to "electric-over-hydraulic" (E-over-H) vs electric. However, I've fooled around with so many different things I'm not sure how long it's been set that way. I'm set up in a campground in Brownsville, TX. It never occurred to me to test the brakes with the E-over-H setting in the past.
Can anyone who has tried this setting tell me how you're electric trailer behaves if you have this set incorrectly?

Thanks,
Dustin

[D2Reid]

I am not the best resource here but I can offer a couple of basic checks that you have probably already done. I don't know for a fact that E/H setting is a lot different on a Tundra, but I suspect it does make a difference. I would put it back on Electric.

Second, basic brake test is to roll forward at 15 mph on gravel and manually apply the brake controller, assuming the built in Tundra has it. The trailer should slow to a stop without jerking or sliding tires. If tires are locking up, you need to note which ones. If only one or two brakes are working then the tires tend to lock up during this test. If the power setting is too high the tires will lock up.

I know, it's minimal and not very specific, but it's a start.

[toolman.dustin]

D2Reid, thanks for the reply. I have done the 15mph gravel test you suggested and the front tires lock up and slide while the rear tires roll. I suspect that's because the rear tires are carrying more load than the front. I haven't weighted the axles separately, but from appearance the trailer sits a couple inches lower in the rear. I've lowered the controller power setting down to 1.0 and still the front tires slide to a stop.
From what I've read the Tundra has a "progressive" integrated brake controller, so it should apply brakes proportionate to the pressure applied to the truck brakes. The fact that the trailer tires leave a black mark on pavement even with a controller setting of 1.0 suggests something is badly amiss. I just can't quite figure it out. I've pulled the drums and cleaned them and the brake shoes, made no difference.
Anyway, perhaps someone else will come up with an idea. I've done a lot of brake work on vehicles (before disc brakes became standard) so I'm pretty familiar with what to look at, but this is a mystery.

Thanks again for the reply,
Dustin

[dryfly]

I would sure assume "electric" would be the correct setting. I have a Reflection and my Prodigy P3 is set to electric and works fine.

The fact that the controller is set to 1 and still having issues would indicate a problem in the controller. However, why only one axle locks up indicates possible multiple issues. I doubt weight could make that much difference.

Other than the controller, my concern is only one axle locking up. I would want to rule out that you do have +12vdc power to the brakes on the axle that is not locking up? Is there a possibility that the brakes are that far out of adjustment??

[toolman.dustin]

dryfly - thanks for the reply. I've manually adjusted all 4 brakes before I left home so they just drag when rotating the tires (off the ground). And yes, electric is the correct setting. I'm not sure at what point I accidently changed it to EOH. I guess I need to hook up the trailer and try it out again now that I've switched it back to electric. My plan was to install new tires before I return home but I don't want to do that until I figure out what's up with the with the brakes. The 1000 mile drive from Kansas to Brownsville wore some flat spots on the front axle tires. This'll give me something to do for the next 7 weeks. I've read dozens of articles but can't find one that explains the output voltage signal difference between electric and EOH.
Thanks again.
Dustin

[dryfly]

You did not mention if you checked for +12vdc at the brakes. I recently saw a tip on how to do a quick check on this. Hold a compass near the brake drum and activate the brakes. The magnetism of the brake magnets will cause the dial on the compass to move. This does not tell all when checking faulty brakes, but at least tells you that you are getting current to the brakes and the magnets are activating. Good luck and keep us posted as to your solution.

P.S. wish I were in The Valley!

[toolman.dustin]

dryfly - I did clamp an amp meter to each magnet line separately. Each one drew either 1.5 amps or 1.7 amps. Most articles indicate they should be drawing 3 - 6 amps ..... But, that would depend on the voltage. And, apparently the voltage varies depending on the setting of the controller gain and/or the rate of deceleration. So, tomorrow I'll try and take some voltage readings but of course the vehicle will be stationary. I'm afraid I'm being forced to learn things I didn't really want to know. One article I read said the "blue wire" feeds the voltage to the brake line and would vary between 3 volts and 14 volts depending on the gain setting and deceleration rate. I guess I'll just have to experiment. I wonder what would happen if I cut the power to the front axle and left the rear axle powered. I wonder if the rear if the rear tires would grab then.
Thanks for thinking about this. Please continue to post thoughts, I'm looking for places to begin. Anyway, I'll post the results of that testing and perhaps your or someone else will be able to make heads or tails of it.

thanks,
Dustin

[TyeeMan]

Yep, electric would be the correct setting because that's all your trailer brakes are is electric. There are no hydraulic components. As far as the progressive braking goes, if the controller in your Tundra is anything like a Prodigy, then there is a little pendulum in the controller. So you will have your base brake setting voltage. When you're going down the road, if you really get on the brakes in your Tundra, the pendulum in the controller swings forward adding power to the trailer brakes. As the forward inertia subsides and you come to a stop, the pendulum comes back to it's original position and you are once again back to your base power setting/voltage on your controller.

One thing comes to mind. Have you checked for leaking grease seals which would lead to grease on your front axle? Grease on the brake pads can cause tires to grab and lock up.

[AZMike]

Funny that I came across this thread now. The brakes on my 2600RB have been very grabby from when I picked it up, meaning I could not do the initial setup properly with my brake controller. The brakes would lock up no matter how I set the initial voltage on the controller. This controller has worked fine on the other two trailers that I've recently owned. I took it in for some warranty work this month and told them about my issue, and that I felt pretty strongly that the brakes needed to be adjusted. Well, lo and behold, when I picked it up, they told me that the brakes were fine, that I needed to adjust or replace my brake controller. Do you know how they check them? They pull the breakaway switch and if all of the magnets energize then the brakes are fine! Well, I was a brake mechanic in a prior life (when disc brakes were in their infancy) and I know when drum brakes need adjustment. So, here I am, at my campsite, having just completed a brake adjustment on all four wheels, and I could not believe (or maybe I could) how far out of adjustment they were. I'm sure that they were not adjusted since Dexter built the axles. Why can't service people actually listen to customer's problems? There were other issues that I can rant about, but this one was pretty important.

[LaMancha]

Check to see that your trailer is exactly level when all hitched up. If you are nose high, that can take some weight off the front axle. Also make sure that you have power to the rear axle brakes as well.

These are leading shoe brakes so the magnet just gets them in contact and the drag from the shoe activates the rest of the system. If the brakes and/or drums are worn excessively or way out of adjustment, the braking effect will be amplified.

This is why I hate drum brakes on trailers and have always opted to install disk brakes.