Jake Braking A 5er Down Long Steep Incline

[Rollochrome]

Just arrived at our vacation destination yesterday.

I had my factory “jake”brake set and the cruise control on when I crested the top of the largest hill going into this part of the country. I’ve never towed a fifth wheel through this kind of environment before and felt like I was looking over the top of a roller coaster when I looked down the several mile long descent

My F350 downshifted all the way into third gear and held me at 55 miles an hour from the top of the mountain to the bottom of each mount I encountered

After I went up and down several mountains like this however it occurred to me that I might be creating conditions conducive for a jackknife if I didn’t have any braking on the trailer at all in such a descent since the wheels of the truck were providing the resistance going down the hill via engine braking and the wheels of the trailer were just rolling freely.

Do I need to be using my integral brake controller in such a condition to apply a little bit of braking to the trailer all the way from the top of the mountain to the bottom?

[Travlingman]

Retired JSO wrote:
I tow in tow mode and use cruise control all the time with the exhaust brake engaged. The OP has a 2019 F-350, I have a 2018 F-350, my exhaust brake has no auto, it’s either on or off.

If your F-350 is a 6.7 diesel, then you have an auto mode. The first push on the exhaust brake is manual mode and the 2nd push of the button is auto mode. This started with the 2017 models.

[cummins2014]

JKJavelin wrote:
Cummins12v98, I believe this how the Ram engine brake works:
Full mode, just letting off the accelerator will activate the engine brake.
Auto mode, you must tap the brake pedal to activate the engine brake.
I prefer the Auto mode to prevent it slowing down all the time, so I am able to coast. My trailer weighs near 12k lbs.
JK

Of course depending on the hill , that’s exactly why I use cruise and it maintains the speed I set it , just let it do it’s thing . I’ve come off some very long grades doing that , with everything under control and maintaining a constant speed . None of this speeding up tapping brakes , only to repeat again , and again .

[KD4UPL]

When I drove 18 wheelers with jake brakes I never applied the trailer brakes going down hill. It never even occurred to me. You're thinking too hard about this.

[time2roll]

If the trailer is pushing the truck sideways in a curve hard enough to jack-knife using the Jake.... you are going too fast for the conditions.

[JKJavelin]

Cummins12v98, I believe this how the Ram engine brake works:
Full mode, just letting off the accelerator will activate the engine brake.
Auto mode, you must tap the brake pedal to activate the engine brake.
I prefer the Auto mode to prevent it slowing down all the time, so I am able to coast. My trailer weighs near 12k lbs.
JK

[Cummins12V98]

"We have a 2011 F350 and the true engine compression brake"

Please explain.

[ReneeG]

Retired JSO wrote:
I tow in tow mode and use cruise control all the time with the exhaust brake engaged. The OP has a 2019 F-350, I have a 2018 F-350, my exhaust brake has no auto, it’s either on or off.

We have a 2011 F350 and the true engine compression brake (not exhaust) is only off or on with setting the Tow Haul Mode.

[Retired_JSO]

I tow in tow mode and use cruise control all the time with the exhaust brake engaged. The OP has a 2019 F-350, I have a 2018 F-350, my exhaust brake has no auto, it’s either on or off.

[Cummins12V98]

Auto mode is useless unless you are towing a lighter RV and smaller grades at least with RAM trucks.

I also set my cruise control at a lower speed to maintain the actual speed I want. It varies depending on how steep the grade is. I also on steep grades select the gear that puts me up near the redline for best braking.

I am glad I don't have the ability for the truck to apply my trailer brakes. I like controlling me descent with cruise and proper gear selection for the grade. I never use Auto mode, I have tried but found it useless for my large load.

[cummins2014]

ReneeG wrote:
With the TV in our signature, we never tow using cruise control, preferring to manually be in control when driving (if that makes sense), but always have Tow Mode on. Going down hills when tapping the brake, the trailer brakes are automatically engaged as well. We only use the manual trailer brake control for extra assurance or a little help as needed, which is rarely. Remember in the Mountain West Directory, in the introduction, the author states, "You can go down a mountain a thousand times too slowly, but only once too fast."

I've found with my 2014 Ram cruise on ,and usually set 5 mph lower then I want to descend a mountain grade, It will gain that 5 mph then maintain the desired speed . I have yet to go down a grade here in the mountain west that it didn't maintain the set MPH that I wanted without any further input from me.

The problem for me with just letting off the pedal ,and letting it slow going down a grade is that it slows too much, then back on the pedal , repeating this several times . Now hearing this explanation for auto I may give that a try , like one said he had the feature ,but didn't know how it worked . This was from a ford owner ,so a Ram truck may be different .

[Fulltimer50]

18 wheelers dont seem to have a problem.

[ReneeG]

With the TV in our signature, we never tow using cruise control, preferring to manually be in control when driving (if that makes sense), but always have Tow Mode on. Going down hills when tapping the brake, the trailer brakes are automatically engaged as well. We only use the manual trailer brake control for extra assurance or a little help as needed, which is rarely. Remember in the Mountain West Directory, in the introduction, the author states, "You can go down a mountain a thousand times too slowly, but only once too fast."

[way2roll]

4x4ord wrote:
For down hill descents I run the exhaust brake on “auto”. When the auto EB is selected the back pressure is regulated to try to maintain the speed the truck was travelling the moment either the throttle or brake pedal were released..

Say you are coming down a steep grade and you have the EB set to auto. The speed you are travelling when you release the throttle is the speed the EB will try to maintain; If you come to a curve and apply the brakes to slow down a bit the new speed set point will be the speed you are travelling the instant you release the brake pedal. After the curve if you want to speed up a bit simply touch the throttle slightly until you are travelling your desired speed again …. a new speed set point will be stored the instant you remove your foot from the throttle. When using the auto EB the wheel brakes (truck and trailer) will only be applied in the event the EB is unable to provide enough back pressure to control your rate of descent. In this case the truck will slowly accelerate with the EB providing full back pressure until the engine reaches red line (4000 rpm), at this point the wheel brakes are momentarily applied to slow the rig down a bit at which point the brakes are released and the truck starts to slowly gain speed again. If having this cycle persist is not desirable you can apply the brakes to slow down enough for the transmission to drop another gear.

I'll admit, while I use the EB, I never understood how the auto EB works. Thanks!

[4x4ord]

For down hill descents I run the exhaust brake on “auto”. When the auto EB is selected the back pressure is regulated to try to maintain the speed the truck was travelling the moment either the throttle or brake pedal were released..

Say you are coming down a steep grade and you have the EB set to auto. The speed you are travelling when you release the throttle is the speed the EB will try to maintain; If you come to a curve and apply the brakes to slow down a bit the new speed set point will be the speed you are travelling the instant you release the brake pedal. After the curve if you want to speed up a bit simply touch the throttle slightly until you are travelling your desired speed again …. a new speed set point will be stored the instant you remove your foot from the throttle. When using the auto EB the wheel brakes (truck and trailer) will only be applied in the event the EB is unable to provide enough back pressure to control your rate of descent. In this case the truck will slowly accelerate with the EB providing full back pressure until the engine reaches red line (4000 rpm), at this point the wheel brakes are momentarily applied to slow the rig down a bit at which point the brakes are released and the truck starts to slowly gain speed again. If having this cycle persist is not desirable you can apply the brakes to slow down enough for the transmission to drop another gear.

[ford_truck_guy]

Aren't these new, upgraded diesels a beautiful thing ! ! !

For those who have NOT towed with a newer diesel and engine brake, they really don't know what they are missing.. ! ! that goes for ALL 3 of the big manufacturers . .

ps... as for the question,,,, DRY ROADS = not gonna jackknife.... set it and forget it...