Jake Braking A 5er Down Long Steep Incline

Only if you want to burn them up or wear them out prematurely

If you had the cruise set it is possible that your truck’s computer may have intermittently applied the truck’s and trailer’s brakes to maintain the 55 mph. (This feature is on trucks equipped with adaptive cruise control) If you have your towing display selected when going down a steep grade a bar graph will display the level of trailer braking being applied during the brake applications.

Jackknifing would only be an issue on slippery surfaces, then caution is advised. I have used my exhaust brake on snow covered roads in 4x4 before without issue, you just need to be aware.

On dry roads, it's the preferred option.

Even on slippery roads, it's the first line of defense but keep an eye on things. If it's bad enough to be concerned, better to pull off and wait for better conditions.

I run cruise all the time but “I” manually control what gear I descend in. My trailer brakes are cool all the time.

Rollochrome wrote:
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?

Well the fact that you had the cruise set at 55 tells me dry paved road in 4X2,so little chance of a jackknife.

Your second question, I would tap the service brakes then resume the cruse, unless adaptive then, the cruise should tap the brakes.
If you are on a slippery surface and the TV is in 4X4 then the braking action of the exhaust brake is the same as using the service brakes. If you manually apply the trailer brakes, you could lock them up and cause it to jackknife.

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...

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.

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!

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."