Jake Braking A 5er Down Long Steep Incline

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.