Aces_Over_Kings

Circumstances:
Platinum with 2600 miles, descending Mount Washington, NH.

Hi all,

Question about Hill Descent Control. Used it today for a serious descent down Mount Washington's Auto Road.

While on the summit I read the manual section on the feature. It offers conflicting speed ranges in the manual, (operates at 2-12mph vs operates at speeds under 20mph), but the main issue is that it didn't seem to use engine braking at all.

So I'm driving slowly, engage Hill Descent Control, and it seems to be working at first. It's basically low-speed cruise control. The truck is locked into the speed I set, but then I realize the RPMs are around 1000-1500. Not really engine braking.

So I think, "Okay, it'll manage itself."

I went for a while at about 15mph, and pulled into one of the turnoffs they provide specifically for letting brakes cool. To my surprise, my front brakes were emitting light smoke.

Never did I hear the ABS activate (manual says you might hear activation of the brakes / chattering of ABS) or see the truck lean on the engine for braking, which I assume would be indicated by the RPMs rising.

Anyone successfully used Hill Descent Control that can share their experience? Did your brakes smoke at all too?

Aces_Over_Kings

No one using Hill Descent Control out there?

StevieP65

For engine braking, I'd use Tow/Haul mode, or perhaps even better, put the transmission in Sport mode.

Don't have FX4, so don't have hill descent control.

From an article on cars.com (googled 'FX4 hill descent control'):
(emphasis mine). Looks like it's more geared toward OFF-ROAD use, and does use the ABS, not (just?) the transmission (engine braking).

pb65stang

I really don't think Hill Descent is intended to be used on a paved road, and especially for a long duration like it sounds like you used it for. You probably would have been much easier on your brakes by coasting and using your brakes sporadically as you needed to.

My understanding of Hill Descent (from watching videos, reading articles, and previous trucks with the same technology) was that it's more for off-road hills or rocks, maybe a few hundred yards in length or something. Not a continuous descent down a mountain.

katoom

Actually I tried this out the other day and to my surprise it worked really well. It seemed to me that it used both engine braking as well as controlling the brakes on the truck. My wife even commented how lazy this truck allows people to be.

piercedtiger

I was thinking the same thing. Sporadically use the brakes and/or use the +/- buttons to lock out the higher gears to help hold it back. I haven't used tow mode myself so I'm not sure how that works.

T_R

Hill descent control is not designed for use on paved roads at road speeds.

It's meant to be used off road on loose surfaces at crawling speeds for short duration.

AbitaPro

TR - if that's the case I missed it on the Ford videos where they instructed drivers how to use that feature. I thought it showed, coming down on paved roads, and that you used it to control the speed, tapping pedals, gas to speed up, brakes to slow down. Check out features own Ford owners website.

http://owner.ford.com/how-tos/vehicl...ite-MFPR0215WT

Aces_Over_Kings

That's exactly the video I watched on top of the mountain before I used it. It clearly shows the trucks on paved roads, and moving at a clip. I guess I was just suprised how heavily it leaned on the brakes, and how it didn't appear to be manipulating the transmission at all.

I didn't know if this was by design or if perhaps mine was malfunctioning. And, I should note, that there's a stretch of the road that's dirt anyway.

Ignorant questions:
Why does the surface matter? These grades are such that gravity's doing the dirty work -- I wouldn't think rolling resistance would really matter?

Also, so long as I was operating within the speed parameters (which I was), I don't understand why pavement would cause more friction/heat on the brakes than going downhill on dirt for any given speed?

Anyway, not saying you guys are wrong. But if you're right, Ford did a lousy job of documenting the feature. I mean, in contrast, the 4x4 section says not to use it on dry pavement about 18,000 times.

Hopefully the wisps of smoke were just a little extra wear on the brake pads, or some protective "new pad" chemicals burning off or something.

NoRice

Hill descent is for off road use hence what it only comes with the fx4 package...