[Bob86ZZ4]

You're doing everything right. And you've noticed something that nobody told you about. I had the same experience. Nobody told me about it either. I don't remember what forum I finally found this info out on. Apparently it is a programming thing. They set it up so the engine brake doesn't apply when the cruise control is powered on. Not just when it's set and holding a speed. But just having the power switch "on" for the cruise system. I don't know why they set it up that way but that's how mine is set and it sounds like yours is the same. I've had a lot of practice (about 50k miles) so it's not a problem for me. I usually shut off the engine brake when I'm cruising along. Have the cruise set. Everything is fine. Then when I start to go down a hill i shut off the cruise power switch. Then as the speed starts to increase I switch on the engine brake (mine is a true Jacobs brand so I can call mine a "Jake" brake, but I think Mercedes isn't actually made by Jacobs so to be most accurate you could call it an engine brake). Mine is only two stage. I start with the first stage, then if it's a steep hill and I'm not getting enough slowing I switch to the second stage. Then as the grade starts to smooth out I just switch back on the power to the cruise and push the "set" switch when it's going the speed I want to lock in. I then switch back the Jake to "off." Ready to do it all again. It sounds complicated I guess but I'm used to doing it this way and it works pretty good for me. I was told you can have somebody program it so that the Jake works even if the cruise is set. I haven't bothered trying to figure that out since my system works good for me.

I think Don (Bushpilot) has a similar truck to yours? Maybe he'll post something for us?