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View Full Version : Electric Trailer Brake Controllers--Intertia or Brake Pedal Pressure



Sydwayz
02-09-2009, 06:53 PM
OK, I know the models that are out there, so I don't need this to be a "buy this one because it works great for me" thread.

I have a debate going on here in my head, and I can't seem to land on an answer.

Basically, you have two kinds of trailer brake controllers.

Brake Pedal Pressure models (like the Reese/Drawtite) respond to how hard you press on the brake pedal, get an electronic reading from the hydraulic pressure on your truck's braking system, and then apply a force to your trailer brakes. These devices normally have a setting where you can adjust/fine tune the actual impulse to the trailer, and adjust the trailer brakes' pressure independently up/down according to load/ conditions. These models are usually cheaper, and can be mounted in any place/any direction.

Inertia based models (like the Tenkosha Prodigy) "feel" the slow down of the truck based on how "hard" your truck is slowing down, and then apply a force to your trailer brakes. These devices normally have a setting where you can adjust/fine tune the actual impulse to the trailer, and adjust the trailer brakes' pressure independently up/down according to load/ conditions. These models are usually more expensive, and must be mounted in only a certain, flat plane, facing forward direction.



Here's my big dilemma:

Inertia based models basically works like surge brakes. When the truck slows down, it tells the trailer brakes to slow down. However, my thought is that if your truck is sliding, perhaps with locked tires, perhaps with the truck sliding "sydwayz", the Inertia based models are not going to send all that accurate of a signal as so figuratively put "oh chit, I need to stop". This would be much the same problem as if you apply your surge brakes while going around a curve, and your trailer begins to jack knife. It seems to me that this isn't the best setup. No?

Brake Pedal Pressure based models will "read" how hard you are stomping on the brake pedal, and then send a corresponding signal to the trailer brakes. This is great, but what if your truck brakes rupture a line? Now your hydraulic brake pressure drops, and NOW your Brake Pedal Pressure module is going to think you let off the brakes. However, during normal operation--no matter which direction your truck is facing, even if its at 90* perpendicular to the trailer, if you are stomping the pedal to the floor, it's sending a "panic stop" signal to the trailer.

I know that BOTH types of controllers have a MANUAL switch/toggle/button/whatever where you can grab/tap it in a hurry, and apply the trailer brakes.

I just can't decide which one is best. Has anyone tried both? Can anyone shed their experience?

I'll probably have more thoughts later, but I'm off to dinner.

sledge
02-09-2009, 08:01 PM
Not sure where it fits in, but my Uhaul branded controller gets its signal from the brake "switch." Off or On. It doesn't detect inertia or pedal force. From there it has two adjustments, "Delay" and "Force." Only "issues" I ever had was forgetting to turn down the force with an empty trailer.

MattBMiller
02-09-2009, 10:58 PM
I have the Tekonsha Prodigy in my truck and electric over hydraulic discs on my trailer. Love the setup. It's very smooth. My last truck ('06 F350) had the built in brake controller with applied trailer brakes proportionately to brake pedal pressure. Towing the same trailer, braking with the Prodigy feels smoother. Never been in an evasive situation with the trailer where I had to really test the inertia setup...knock on wood...

Bgchuby01
02-09-2009, 11:04 PM
I use prodigy in my peterbilt and tow lots of different trailers and love the way it works in conjuntion with my trucks airbrakes.

Sydwayz
02-09-2009, 11:08 PM
Jeff, do airbrakes work the same as train brakes? (Component failure)-loss of air pressure = brakes applied?

Chris
02-10-2009, 08:31 AM
You are correct that the inertia controller avoids the issue of line failure. The analogy between an inertia controller to surge brakes is accurate everywhere but in application. Their function is much smoother. The only downside to an inertia controller is that they have to be installed and adjusted properly to function correctly- just slightly harder than the pressure controller. Not hard, but you will have to actually read the instructions and do as they direct- something most of us hate to do.

Short version- inertia is better. Smoother, more linear and more adjustable.

All air braking systems use brake pressure to disengage them. Lose pressure, brakes apply. The next time you're on the highway behind a truck or trailer, look at the actuator cans- there's a little rubber plug in the center. In the cab of the truck there's a bundle of t-bolts. If you pop a diaphragm or need to tow the truck, you pull the plug, engage the t-bolt into a slot in the diaphragm and you screw them open to hold the brakes off.

scottc
02-10-2009, 09:36 AM
I believe there is an issue with anti-lock brakes and hydraulic actuators. They are not compatible.

Sydwayz
02-10-2009, 11:04 AM
Chris, can you comment on US1 Fountain's input from OSO?

" I have the Maxbrake controller for my EOH setup, but it also works for full electric systems. It operates off brake line pressure. It does not have a brake line going to the controller like your Grandpas HK unit. You install a tee coming out of the master cyl in 1 of the lines, and then a pressure sensor screws in there. Which in turn sends an electrical signal to the controller. I'll 'assume' this is somewhat the same concept as the reese/drawtight. So will offer my thoughts as to it's operation as I see it. I don't think the controller will care if it is suppling power to a pump or magnets as far as operational manners.Disclaimer: I have little experince with the inertia units, so might be a little(or way) off on my thoughts. I have seen some controlles that have a 'presignal'(for lack of better words) to start the trailer braking process by means of the brake light switch.I wouldn't worry about loosing pressure myself. As you already stated you have the manual override on either design.If you had the inertia style and lost line pressure, how you going to slow the truck down for the controller to see the inertia? Both systems need feedback for normal operation, either from line pressure or the result of it, that would be lost with a complete tow vehicle brake loss. A couple of the reasons I went to line pressure model for my trailer is for trailer braking at all times with no influence with regards to traction or movement from your truck. Only off the brake pedal, nothing else.Wet pavement, you got trailer brakes. No trailer pushing the truck thru a stop light on wet pavements because the truck didn't have the needed normal traction for inertia feedback. Panic stops on wet pavement are no longer an issue.Backing down the ramp, you got trailer brakes. Stopped on a hill, you have trailer brakes. Did I mention you always have trailer brakes? When I 1st installed the EOH setup, I had the Tenkosha controller. Hauled the boat to the lake for the summer, came home, ordered the Maxbrake pressure type controller. (Not a plug for Maxbrake, but for the pressure sensing controllers) World of difference. I know you said the pressure type controllers are cheaper, but mine was around $400. Maybe mine operates on a different level, in which case, keep that in mind when comparing models. Didn't know Reese/Drawtite has pressure controllers.Hopefully that helps a little, or at least raises more questions for discussion."

I'm concerned that the Inertia based controller isn't "good enough" when the the truck loses traction (sliding) while braking; either straight line hard braking or as the truck/trailer begins to jack-knife.

I like what I read last night on the Max Brake setup.

Chris
02-10-2009, 11:52 AM
First off, you should never be in a position where the truck is sliding. The boat trailer should be braking slightly stronger than the truck and that will prevent that occurrence. And you always have the manual override.

I haven't used a pressure controller since before ABS found it's way onto truck brakes, so I can't answer the compatibility issue. But I know how ABS works- so I'm guessing it taps in before the controller. You might want to double-check on that one.

My paranoia is losing brakes on a downhill- and my aversion to surge brakes stems from that- and a real experience with an equipment trailer that almost got away as a result. But with a properly set up dynamic controller, I don't see the issue.

The biggest issue with a dynamic controller is the failure to properly follow the setup and adjustment instructions.

As far as real-world, I've had my share of rapid stops on wet pavement and never have I had an issue.

Bgchuby01
02-10-2009, 02:36 PM
I hope that I never have a large loss of air suddenly or my truck and your boat will slide to a halt. When you have air pressure that goes in that can chris was talking about and pushes against a spring to unlock the brakes. hence you loose pressure and the spring makes the brakes come on.

buck
02-11-2009, 12:53 AM
We sell strictly pedal sense controllers in the store. (keep in mind most of our sales include an installation) I wouldn't say we sell them because they are better, but we sell them more for our convenience.

Like has been mentioned, an inertia controller has to be set up properly. When set up properly and used correctly it is probably a better controller. Our problem is that the customer, for the most part, doesn't have the understanding or patience to set up and use a controller like this. I can't count how many times we get a call on the phone saying a they have a controller that doesn't work and they want us to look at it. When they bring it in it's usually one that has been jacked with beyone belief. Bottom line, they don't know how to use the darn things.

It's so much easier for us to put a controller in and say turn this knob up if you want more brakes and turn it down if you want less brakes. Keeps it simple for the simple minded folk. Takes stress out of my life too.

If I have a customer that comes in and knows what they want and fully understands the use of an inertia controller then they quickly get what they want. For a user in the know it's probably the way to go.

I use both on a regular basis and either one works fine for my needs.

Buck

Z06
02-12-2009, 01:48 AM
The MaxBrake is awesome. You adjust the amount of force once and never think about it again. Unlike the new OEM's the MaxBrake works with electric over hydralic and can tell the difference between electric brakes vs. electric over hydralic. Seems like the Ford & GM controllers should have been that smart...

I think the MaxBrake is your 3rd type of brake controller.

Bgchuby01
02-12-2009, 06:45 AM
does the prodigy have to be mounted level? Mine is at a 45 degree angle?

Sydwayz
03-10-2009, 02:46 PM
I just ordered the MaxBrake controller from Southwest Wheel also at www.brakecontroller.com

$349 including wiring harness for your vehicle and free 2-day shipping.

I will update on how things turn out once I get it installed.

US1Fountain
03-10-2009, 09:52 PM
Good to hear.

What brand truck is this going in?

Sydwayz
03-11-2009, 04:09 AM
Good to hear.

What brand truck is this going in?

2000 Ford Dually.

buck
03-11-2009, 11:16 AM
Keep us posted on this Brian. I am not familiar with the product and found it interesting when you brought it to my attention. If it works out for you I may see if I can influence one of my warehouses to carry them.

Buck

Sunsation96
03-11-2009, 11:18 AM
I just bought the prodigy and that thing is freakin awesome. Loved it

Sydwayz
03-11-2009, 12:53 PM
This is getting more expensive by the minute. I just had to buy a new Alpine/Sirius/iPod headunit since I want the brake controller in the pocket on the dash where the current Sirius Sportster is installed.

Sunsation96
03-11-2009, 01:38 PM
does the prodigy have to be mounted level? Mine is at a 45 degree angle?

with the prodigy you can go 0° to 70° no more no less

US1Fountain
03-11-2009, 06:04 PM
2000 Ford Dually.


Read this and make sure you look a this tee. I found it to be the wrong one that they send in the Ford kits. I called them to inform them several months ago of this error. Curious if they updated their parts list to the correct one.

The attached pic are of the tees , chitty pics, but the hole size and if you look close at eh middle pic, the taper on the largerer holed tee is flattened out do to it being the wrong one the difference is obvious. I was chasing a slight leak at this tee till I realized it was the wrong one. It just barely sealed, and not by the taper fit. The small hole tee is the correct one. At least on my truck.

Copied from OSO:

After close inspection, it was appearant that the tee fitting shipped with the controller is for a 1/4" line. My '03 Ford truck has 3/16 lines, so the flare joint DOES NOT seal correctly. In fact, it doesn't seal on the taper, but on the tip by flattening the end of the tees flare. I removed the tee and looked at the flare inside the female end of the tee and the tip of it is flatened because the line isn't large enough to fit over the taper. It also barely screwed into the M/C by a couple threads. Idoubt it seated real good inside the M/C either. A major fug up on their part, that could lead to a major brake failure.
I found the website for that tee and it is made for a 1/4" brake line pass thru with a 3/16 take off. The one shipped with my controller is pt # 7904. (will be stamped on the side of the tee) The correct one for my Ford is #7933. Napa has them in stock for a few bucks.



http://www.imperialinc.com/pdf/Section_F.pdf#page=6
'scroll down to F6'


I ended up drilling and tapping the take off port of teh tee to screw the sensor directly to the tee for a much cleaner look. Didn't care for the short tube with adapters look.

Sydwayz
03-12-2009, 02:06 AM
Read this and make sure you look a this tee. I found it to be the wrong one that they send in the Ford kits. I called them to inform them several months ago of this error. Curious if they updated their parts list to the correct one.

The attached pic are of the tees , chitty pics, but the hole size and if you look close at eh middle pic, the taper on the largerer holed tee is flattened out do to it being the wrong one the difference is obvious. I was chasing a slight leak at this tee till I realized it was the wrong one. It just barely sealed, and not by the taper fit. The small hole tee is the correct one. At least on my truck.

Copied from OSO:

After close inspection, it was appearant that the tee fitting shipped with the controller is for a 1/4" line. My '03 Ford truck has 3/16 lines, so the flare joint DOES NOT seal correctly. In fact, it doesn't seal on the taper, but on the tip by flattening the end of the tees flare. I removed the tee and looked at the flare inside the female end of the tee and the tip of it is flatened because the line isn't large enough to fit over the taper. It also barely screwed into the M/C by a couple threads. Idoubt it seated real good inside the M/C either. A major fug up on their part, that could lead to a major brake failure.
I found the website for that tee and it is made for a 1/4" brake line pass thru with a 3/16 take off. The one shipped with my controller is pt # 7904. (will be stamped on the side of the tee) The correct one for my Ford is #7933. Napa has them in stock for a few bucks.



http://www.imperialinc.com/pdf/Section_F.pdf#page=6
'scroll down to F6'


I ended up drilling and tapping the take off port of teh tee to screw the sensor directly to the tee for a much cleaner look. Didn't care for the short tube with adapters look.


Thank you so much for this information. I may be trading some more info with you when I get the unit later this week. Thanks again!

Sydwayz
03-14-2009, 01:20 AM
Got home late tonight, and looked in the box; and they shipped #7904 with mine.

I stopped by Napa and traded the T in on a 7933 today. I also bought another piece of brake line that is hand-shapable, which will make the install around the MC really simple.