exhaust brake/trailer brakes

[DuaneOlson]

just got an exhaust brake for the 24v and was wondering which trailer brake controller is the best to work with an exhaust brake. The brakesmart uses line pressure so it seems that you could do a lot of downhills without the controller ever kicking in the trailer brakes which seems like the trailer would be "pushing" a lot. How about the new prodigy does it work any better??

 

[Joe G.]

I have a Prodigy. It will come on anytime the brake light is on. So I rigged the exhaust brake to turn on the brake lights. That works well in most cases. I found that in steep slow places it held the trailer brakes on more than I liked so I installed a switch so that the exhaust brake activating the trailer brakes is optional. That set up works very well. Especially if I'm on a highway and using the cruise control. When the exhaust brake comes on the trailer brakes do too. As soon as it drops below the cruise setting the brakes let go.

 

[WestTN]

Prodigy & E-brake

I have this combunation and I love it. I have the e-brake attached to pin 20 of the ECM. It is completely independent of the trailer brakes. This allows me to disengage the cruise when going downgrade and holding speed in check without generating heat and wear in the trailer brakes. This normally works great. If, however, the grade is steep, I will use the brake pedal to release the cruise and not let up on the pedal. Since the Prodigy works by sensing the angle of decelleration on an inertia sensor,determing the angle at the instant the brake lights come on as no braking yet, it applies the trailer brakes proportionally to the total decelleration forces acting on the truck. This thereby incorporates the e-brake force in the calculation for the trailer brakes. This mode also works great and saves on both sets of brakes. I can't therefore see any reason to connect the e-brake to the brake lights, as that would allow unnecessary trailer brake wear.



I AM thinking about making a switchable connection for when I am NOT towing, since I use the e-brake a lot when slowing down. I currently have to remember to touch the foot brake lightly to turn on the brake lights.

 

[GFrance]

I'm glad my controller doesn't work that way. I think it would wear out my trailer brakes in a hurry. Useing my smart controller to lock up my torque converter my exhaust brake holds back my 12,000lb 5vr on most grades without touching the brakes. Going down to Calif. comming off the Siskiyous only have to touch the brakes a couple of times. Start down the hill in a lower gear & keep the speed down so if I need those brakes I'll have them.

 

[Joe G.]

I've found by experiment that my trailer brakes are actually in use very little the way I have it hooked up. When the exhaust brake comes on and causes the trailer brakes to engage speed drops below the cruise setting right away. It doesn't slam on or anything like that. Just a nice even tug to slow down easy and it lets go. Thus there is little strain on the torque convertor clutch as well as the brakes. It even works that way going down Donner. Before I set it up this way the exhaust brake stayed on all the way down that hill even with the cruise control. The whole business feels like it stays in a straight line better now than having the trailer just lean on the truck all the way down the hill. I put maybe 4000 miles on my 32' travel trailer in a year. Really doubt that I will have brake wear that amounts to anything in the next ten years. I have a switch to turn off this feature in steep twisty places like the Buckhorn grade on SR299 in CA. That's 2nd gear and exhaust brake with help from the service brakes in the turns. With this feature off the trailer brake can cool between the turns. There are not too many places like that around. I found one in OR and a couple in ID last year. Setting it up and doing some experiments showed me that preconceived opinions I had were just that.

 

[Eric_77]

An exhaust brake is designed to be used so that service brakes are allowed to remain cool and functional for emergency/hard braking or just to minimize brake wear. By turning on trailer brakes you have defeated the advantages the exhuat brake are designed to give. Call Pac-Brake or Jacobs for proper use and installation.





If you feel that the trailer is/would be pushing you with exhaust brake and no trailer brake just imagine when you hit the service brakes and have no tailer brakes(because they are overheated from use all the way down hill).

 

[klenger]

I never felt any tendenancy for my trailer to push my truck downhill with just the exhaust brake on, and this includes some pretty nasty grades (7% 10 miles @ 10,000 feet) in Colorado. If you feel you need a bit more braking than the exhaust brake is providing, apply light pressure on the brake pedal and let the truck and trailer brakes do their job together.

 

[Joe G.]

The point is that instead of theories and guesses, I wondered what would happen and tried it out. Now I know and like the results.

 

[clem]

E-Brake and brakes

How many 18 wheelers have there brakes come on with there E-Brakes? As stated above the E-Brake is used to take the load off the brakes. My set up is E-Brake on to slow down and save the brakes. In over 80K this has worked great would not change a thing we tow both coasts and all hills in between

 

[Dean Upson]

I like my Prodigy/Jacobs e-brake combination. I feel in control and have never experienced a "pushing" feeling from my 15k fiver.



Dean

 

[Turbo Thom]

Joe:

It's your trailer and your brakes. Nobody said you can't be different. I just like to know when I need a little extra my trailer and truck brakes are cool enough to do me some good. That's the way I like it and it works for me.



. . Preston. .

 

[Joe G.]

Preston,



I was not going to post on this thread anymore, but I will make a couple of comments. Not one of the people who are acting like I have commited some sin or have lost my senses have any experience with this set up. The fact is that except for those grades that are so steep or crooked that service brakes are necessary the brakes are not on long enuff to get hot. That's why I have a switch to turn this feature off. Even going down Donner using the cruise the trailer brakes are not on enuff to make them hot. I like the way it works and I like having my brake lights come on when the exhaust brake does. I explained how it works and how to set it up. If anyone doesn't like it then don't do it.

 

[Turbo Thom]

Now, the feature where the brake lights come on when the e-brake does, sounds like a good idea to me. ... ... ... . I'm not saying your crazy. I just don't want it that way. So like you say, don't do it.



. . Preston. .

 

[Berrigan]

Any of you guys using the Pac? If so do you have the hd valve springs and the second hole plugged? And if so did that improve your e brake performance alot.



Was just woundering cause I still gotta use my service brakes more than I like on some grades and Im running both holes open and standard springs. Thanks Bill

 

[Joe G.]

Turbo Thom,



You can rig it to turn on the brake lights without turning on the trailer brakes with a relay and a couple of diodes.



Berrigan,



I have replaced my exhaust valve springs and plugged the hole. It does make quite a bit of difference.

 

[clem]

FOR MY 2 CENTS. The last thing I want to happen is my trailer brakes coming on with the E-brake. Also the more things you install in the brake system the more changes you have of something going WRONG. Always use K,I,S,S. Keep It Simple Stupid always works for me. Adding relays in your brake system does not follow the KISS rule. Thats my 2 cents. Also if I am coming down Downer Pass I think I know what brakes need to be used and the last thing I need is HOT trailer BRAKES:-{} :--)

 

[Joe G.]

What are you so upset about? No one asked you to do it. How in the world to you have any idea how it works in the real world if you haven't tried it? I've gone down Donner with this setup. Both sides. Have you? How do you know this setup causes brakes to get hot? Have you tried it? It turns out that it does NOT result in hot brakes on most all roads includeing Donner and the steep grades on I5 in OR and and US95 in ID. How do I know? I tried it.

 

[Eric_77]

Joe I think you need to rethink what you are saying brakes operate by converting rotating force (tire spinning as result of vehicle moving) into heat so by engaaing trailer brakes they are going to get get hot. How hot? well from your circumstance you indicate it does not overheat your brakes if you are closer to max load it would. Is a brake at 200 degrees going to have as much brake capacity as one that is at 70 degrees? no it is not, is it going to still have a enough brake capacity for the stops you have encountered? you indicate it has so for you yes it does work. Is it the way an exhaust brake system is designed to operate? no as you do not have the cool maximum stopping abilty sitting in reserve that most users of exhaust brakes desire.



Here is second issue to think about the Dodge brakes are better than any trailer brake I have seen. The trailer brakes are now not as effecient at stopping if energerizing with exhaust brake so the Dodge brakes are even better then trailers. Common, very common, cause of jacknife is trailer brakes not braking as hard as truck brakes due to load shift, improper brake balance, misadjusted brakes, etc you have just added to the likihood of a jacknife with less braking from trailer.



Joe I think you would find better overall performace if you leave trailer brakes off and downshift one more gear to maintain your max speed or apply brakes as needed.

 

[clem]

Sometimes a person will fight to the very end even if they are wrong just to save FACE. Pride can Kill.

 

[Joe G.]

I see. More untested theory. When I responded to this thread I was trying to provide some useful information. I didn't want to get into an argument. Nor do I recall asking for any advice.



When I first tested this setup I was not worried about the trailer brakes dragging. That does not happen except in extreme situations. I have a switch to turn it off in that case. What I was worried about was too aggressive brake behavior. Like sliding the trailer wheels or something like that. It was pretty aggressive, but an adjustment to the Prodigy settings tamed that. It's a positive feedback situation. The e-brake comes on which switches on the Prodigy. The Prodigy is an inertial brake controller so it senses the slow down from the e-brake and it applies the trailer brakes. That causes more slowing with means more brakeing, etc, etc. Not exactly a drag the brakes down the hill and they get red hot kind of deal at all. The way it works with my cruise control is that when the cruise setting is exceeded the brakes come on. In a few seconds the speed drops below the cruise setting so a little throttle is applied and braking stops. Speed slowly increases until the cruise setting is exceeded and the cycle is repeated. Braking periods are much shorter than throttle on periods. During my first round of tests I checked to see if there was any excessive brake heat by stopping at the bottom and running back and feeling the drums. Not even close to an ouch from putting my hand on them.



My first intention was to cause the brake lights to turn on when the e-brake engaged. Warning tailgaters. Then while I was thinking about how to do that I realized that it would also turn on my trailer brakes. I wondered if I wanted it to do that or not. (a diode would allow turning on the brake lights without the trailer brakes) So I set up a bread board test to see how it acted. I liked the way it worked so I installed it.