"Lumpy & grabby" brakes

myredracer · 04-09-2012, 12:55 PM

Our TT is fairly new (purchased last August) and we are just out on our 3rd trip this weekend. I initially set our brake controller down to 2 until I thought it felt right and the trailer brakes weren't locking up.

When the brakes are cold they really grab and lock up. Exiting a campground is fun because everyone is wondering why someone is skidding loudly on the way out.

After being out on the highway and the brakes are good and warmed up, they feel quite lumpy when applied. It's lumpy enough that the trailer jerks up and down. Do the brake drums need turning or is something set wrong or is there something else wrong? Maybe they will break in over time?

I'd rather not have to take the trailer into the dealer because they'll probably want to keep it for a month like last time (for a few simple warranty repairs). They don't appear to request authorization from Forest River until they get the unit on their lot and then it just sits there....

Fire Instructor · 04-09-2012, 01:01 PM

Sounds like a brake controller problem. Is it a good controller, or an el-Cheapo one that dealers ofthen "throw-in" at time of purchase? I switched to a Tekonsha Prodigy from the dealer installed controller, and all such problems disappeared!

trudinator · 04-09-2012, 01:05 PM

When I read the title to your post I expected to be reading a joke of some kind. LOL.

**bikendan** · 04-09-2012, 01:24 PM

You really need to post what controller you have.

pg_rider · 04-09-2012, 01:29 PM

I have similar issues with my Rockwood brakes and Prodigy P2 controller. The trailer brakes can be grabby (although they don't lock up) and sometimes feel like they're pulsing as if I've got a warped disc (even though I think they're drums). Curious to hear if there are some obvious things to check!

myredracer · 04-09-2012, 01:54 PM

Our controller is a Draw-Tite Activator II. It was installed by an independent shop. Not sure if it is a good one or not although a Google search came up with Draw-Tite and "economical" in the same sentence.

I hadn't suspected the controller because it feels a lot like a warped drum(s). Isn't an electric brake either on or off with the only variables being time delay and force? So there isn't really any modulation going on from the controller is there?

Dave_Monica · 04-09-2012, 02:13 PM

You want one with a mercury switch that detects the level of de-celeration and adjusts the current to the brakes accordingly like a Prodigy P3.

Dave

buffalohunter · 04-09-2012, 02:23 PM

I would also consider checking the torque on all of the lug nuts. Loose each one and then re-torque them to specs using the correct sequence in the tightening process. You might also go through the sequence with 1/2 then 3/4 and finally full torque. It wouldn't be the first time it solved a problem like that.

Just my thought anyway.

**bikendan** · 04-09-2012, 07:36 PM

you want a proportional controller, like the Prodigy, not a cheap time-delay one.

myredracer · 04-10-2012, 03:39 PM

Trudinator: Perhaps you were looking for a Lumpy, Grabby & Moe joke? The movie opens next week.... Would love to see it actually.

We just got home with the TT. I have noticed now that on slower downhill roads where more braking is needed, that if I press the brake pedal hard and longer, the brakes are nice and smooth. It's when I let my foot off the brake a bit and try and modulate the pedal, it goes into the lumpy mode.

So now I would say it HAS to be the controller. I will be looking into the Prodigy P3. Looks like Prodigy has a harness adapter so that I can just unplug the old unit and plug in the new one without having to rewire anything.

I tightened up the wheel nuts in the cg and they were all pretty tight.

So this should be an easy upgrade/fix that will only take a little $$. It's just a hobby, so what's a few more bucks? Wish we had known in the beginning and we would have forked out the extra.

Thanks for all the tips and help.

Thurman · 04-12-2012, 09:28 AM

Electric trailer brakes can feel "lumpy" by nature of their design. A steel insert in the brake drum(s) passes by the electromagnet with each rotation. When the electromagnet is energized, by applying your tow vehicle brakes, the steel insert wants to stop at the magnet, thus braking power. Cold brakes do this even worse. I always warm mine up by applyng a litttle pressure when starting out, even with my work trailer. I upgraded to a proportional controller also and this made a big difference.

myredracer · 04-12-2012, 10:37 AM

Thanks for the info. Thurman. That's the kind of info. I've been looking for. Makes a lot of sense now. That why it feels sort of like each tire has a flat spot on it and I get a pulsating lumpy feeling.

Have been trying to learn just how the Draw Tite controller works. I know there is an adjustable time delay and force. But does the controller ramp up to the preset force setting? I'm thinking yes because maybe what's happening when I let off the brakes and then lightly re-apply them on and off or when I reapply them is that the brake shoe force is ramping up to the max. setting each time it gets a braking signal. And if I'm cruising along and just want to lightly use the brakes to slow a tiny bit, that first the truck's brakes work and then the trailer brakes ramp up and kick in and can give too much overall braking effort and thus I immediately let off the brakes entirely.

Maybe it's just the way the beasty works and I need to get more used to it. Perhaps I could try playing with the settings a little? Otherwise, a new Prodigy P3 is now on my most wanted list.

Dave_Monica · 04-12-2012, 11:05 AM

What you're talking about is the nature of the controller. I found that if I set the controller to provide adequate braking at normal speeds, it was way too aggressive at slow speeds.

Trust us on this...get the P3 and set it and forget it.

Dave

MtnGuy · 04-12-2012, 12:57 PM

Quote:

Originally Posted by myredracer

Have been trying to learn just how the Draw Tite controller works. I know there is an adjustable time delay and force. But does the controller ramp up to the preset force setting? I'm thinking yes because maybe what's happening when I let off the brakes and then lightly re-apply them on and off or when I reapply them is that the brake shoe force is ramping up to the max. setting each time it gets a braking signal. And if I'm cruising along and just want to lightly use the brakes to slow a tiny bit, that first the truck's brakes work and then the trailer brakes ramp up and kick in and can give too much overall braking effort and thus I immediately let off the brakes entirely.

Maybe it's just the way the beasty works and I need to get more used to it. Perhaps I could try playing with the settings a little?

A time delay brake controller like the Activator II usually has 2 settings. The braking power, and the rate of application. If you set the rate of application, say for 4 seconds, the the braking power will gradually increase to the maximum you have it set for in 4 seconds. Second #1, is .25%, second #2 is 50%, etc. If you need to make an emergency stop, then you will not get fulling braking power until second #4. If you set the rate of application lower, say 1 second, then you are gonna get 100% of the trailer braking when your brake pedal is depressed for 1 second, leading to abrupt stops when you just want to slow down.

Any time the brake pedal is released, the process starts all over again. You can have a high power setting and low rate of application, and maybe "pump" your brake pedal when trying to gradually slow down. Or you can have a slow rate of application and a hight power setting, and get in the habit of reaching down and applying the manual control when more braking is needed. The manual control usually brakes up to the maximum power setting you have set.....if that makes sense.

That type of controller was all that was available many moons ago, unless you had a controller that was actually attached to the brake pedal. Times have changed, and a controller that measures deceleration is a much better option these days.

Sgt. Schultz · 04-12-2012, 11:20 PM

Hello redracer some info that may help :Trailer Brake Controller Information | etrailer.com & HowStuffWorks "Brake Controller Monitors"

The issue you are describing does lead one to believe it is your controller an interim solution could be that in the CG / parking lots etc. set the delay higher and as you get out on the road decrease the delay to the desired setting

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