Engine brake and trailer brakes

[TexasChris]

I heard a couple times, but nothing official, that if you are running your engine brake and it engages, it applies your trailer brakes.

Those people said it would lock up their trailer tires.

Any truth or tips on this subject?

We traveled from from Fort Worth to Nashville yesterday then back home tomorrow hailing a kitchen trailer. Might use it in the hills of Tennessee.

2021 Dynamax Force HD 37BD

[dalford]

No, the engine brake is just what it implies, an engine brake.

The eb uses the back pressure of your engine to slow you vehicle. Just like downshifting but added back pressure to slow you down.

I’ve traveled some long down grades out west and using eb never touched the brakes. The eb did the braking.

I use cruise control and as I reach the crest I adjust the speed to much lower than I want to go as the truck overshoots the set speed by 5+ mph or so but then eb sets in and brings you down to the set speed. You then can bump up the cruise by mph increments.

If you don’t like using cruise then tap your brakes to cause your truck to downshift until you get the speed you want

Use it, you will love it

[timfromma]

What ^^^^^ said.

[Bill Davis]

Yes, the m2 turns on the brake lights when the jake brake applies which in turn applies the trailer brakes.

[CedarCreekWoody]

Originally Posted by Bill Davis

Yes, the m2 turns on the brake lights when the jake brake applies which in turn applies the trailer brakes.

This is a contradiction to earlier comments. Yes or no, it applies trailer brakes?

[Daniel.mullins4]

2011 Chevy duramax, I use my engine brake as well using the cruise control, next time I am going to monitor the trailer braking on my dash, it should show braking anytime trailer brakes are applied.

[TexasChris]

Originally Posted by CedarCreekWoody

This is a contradiction to earlier comments. Yes or no, it applies trailer brakes?

The trailer has brakes.

[doc73]

Originally Posted by TexasChris

The trailer has brakes.

I think it will depend on the brake controller and truck setup.

On the M2, as do many larger trucks,the brake light some on when the eb activates. On my Chevy 2500 they do not.

Why it might depend is my Chevy uses a built in brake controller and does not activate the trailer brakes once the eb activates with the built in brake controller.

A vehicle might have a brake controller that is wired into the brake lights so if they were to activate when the light come on (ex the eb activates them) then yes the trailer brakes will activate. (Had a put that was wired to the brake lights once for a Hopkins brake controller)

So it will depend on your setup.

[johnlochbuie]

Who in the world would have trailer brakes hooked into the brake lights been wiring trucks for years for trailers and have never wired into brake lights.

[Mike134]

Sounds like you need to give more details about the tow vehicle and type of trailer brakes.

For example, my old popup had surge brakes, if the engine brakes hard enough they WOULD apply no need to touch the brake pedal. My 28' camper I tow today has electric brakes and they will not apply only from engine braking.

[TRN]

Originally Posted by johnlochbuie

Who in the world would have trailer brakes hooked into the brake lights been wiring trucks for years for trailers and have never wired into brake lights.

Are you setting up air brake systems?


I've used the Prodigy brakes on many of my pickups and on my DX3, and yes, they use the brake light to activate the trailer brakes. However, the trailer braking is proportioned using an accelerometer within the Prodigy unit, so the faster you are slowing, the more trailer brake you get. When I use the brakes in my DX3, I see the Prodigy system activate and then the amount of brake being applied to the trailer is proportional to the deceleration rate of the tow vehicle.

I've never noticed the brake proportioning numbers appearing on my prodigy when EB activates, likely because the deceleration rate is not great enough to activate the trailer brakes. I'll look tomorrow when I'm traveling.

https://www.etrailer.com/question-116456.html

[NavyLCDR]

Originally Posted by johnlochbuie

Who in the world would have trailer brakes hooked into the brake lights been wiring trucks for years for trailers and have never wired into brake lights.

Me for one. I am one of the thousands, if not millions of people that has an aftermarket proportional brake controller (installed in my wife's Dodge Grand Caravan) that uses the brake light switch for activation. I had a timed style controller installed there before, which used the brake light switch for activation. I installed a Curt Spectrum controller in my Dodge Durango which activated from the brake lights.

[KMP44]

The original post is in the Dynamax forum, so the question is specific to the Freightliner chasis, not a pickup.

[dalford]

I’m confused. The op asked about his engine brake not his brake controller. Maybe different on a MH but I doubt it.

EB downshifts engine and used engine back pressure to slow vehicle.

Do your brake lights come on when you downshift? Mine don’t nor as far as I know no one’s does?

Engine brake just brakes the engine tranny speed. I even use tow/haul when not pulling our 5th wheel. It is not connected to brake controller.

[NavyLCDR]

Originally Posted by dalford

I’m confused. The op asked about his engine brake not his brake controller. Maybe different on a MH but I doubt it.

EB downshifts engine and used engine back pressure to slow vehicle.

Do your brake lights come on when you downshift? Mine don’t nor as far as I know no one’s does?

Engine brake just brakes the engine tranny speed. I even use tow/haul when not pulling our 5th wheel. It is not connected to brake controller.

Motorhome or truck does not matter. It depends upon what the trailer brake controller uses for activation.

Also, see this post:
https://www.forestriverforums.com/fo...ml#post2483472

Lots of forum posts state that brake lights with engine braking is a programmable function. So, if the brake lights are programmed to come on with engine braking, and the brake controller installed uses the brake light function to activate, then the trailer brakes would be applied with engine braking.

[johndjmix]

Let me simplify this entire thread


If your brake controller apply a brakes (you see it on its screen) when only engine braking, install a separate pressure switch for just trailer brake controller. Very easy to do, 10 min job.

If it does not apply the trailer brakes on engine braking then forget about it - your fine.

—John

[aircommuter]

I had to do away with the surge brakes on my boat trailer because I live up the mountain and going down to the lake with EB on the surge brakes cooked the trailer brakes.
Not sure that is what OP is referring to. Like others said the pendulum type actuator can also apply the trailer brakes from the deceleration provided by the EB.

[Mike134]

Originally Posted by TexasChris

I heard a couple times, but nothing official, that if you are running your engine brake and it engages, it applies your trailer brakes.

Those people said it would lock up their trailer tires.

Any truth or tips on this subject?

We traveled from from Fort Worth to Nashville yesterday then back home tomorrow hailing a kitchen trailer. Might use it in the hills of Tennessee.

2021 Dynamax Force HD 37BD

Be very careful listening to "internet experts"!!

I googled your question since I have no experience with a Freightliner motorhome and it seems that yes your trailer brakes would apply just from engine braking. That question also came up on this forum.

https://www.forestriverforums.com/fo...ke-250521.html answer #6

good luck and remember "we are not experts but play one when online"

[Oaklevel]

Originally Posted by TexasChris

I heard a couple times, but nothing official, that if you are running your engine brake and it engages, it applies your trailer brakes.

Those people said it would lock up their trailer tires.

Any truth or tips on this subject?

We traveled from from Fort Worth to Nashville yesterday then back home tomorrow hailing a kitchen trailer. Might use it in the hills of Tennessee.

2021 Dynamax Force HD 37BD

!!! The op has a 2021 Dymamax Force maybe Brian can help.

I know on a pickup the engine brake will not activate the trailer brakes but on a bigger truck I have no idea. Technology changes often.

[doc73]

Originally Posted by johnlochbuie

Who in the world would have trailer brakes hooked into the brake lights been wiring trucks for years for trailers and have never wired into brake lights.

Apparently everyone but yourself