How to manage brake systems on long downhills.

[davidrrand]

Timely subject for us as we are leaving Ridgway SP tomorrow and have three pretty high passes between here and Durango on 550 in Colorful Colorado. Thanks for the tips. So far so good thru SD, the Bighorns in WY through YS and up to Glacier then down through the Bitteroots into ID along the Salmon River then express thru Salt Lake and NE Utah to Colorado's Roaring Fork Valley and now in the San Juan and Cimarron Mtns.

Any tips for New Mexico while heading back to Georgia? Thanks. 😊

[jsutro]

As usual, Forum members provided useful thoughts about dealing with AS realities.

Good advice, darsea, to never let the trailer push the TV rear end sideways.

I got into a fish-tail situation years ago, and it still gives me the shakes. A professional truck driver provided a simple way to get out of it: "Stretch it out.
Apply trailer brakes, and moderate acceleration to straighten out the rig, then back off the gas and stay on the trailer brakes to slow down."

I found more valuable information in the owner's manual, when I re-read it with a long curving downhill fresh in mind. As always, RTFM.

Thank you all for sharing your experience and insights. jsutro

[Holy Grail]

There's nothing that compares to a diesel TV with a tow/haul function on along with an exhaust braking system. Anything else in the Rockies is extremely dangerous. Gas engines lack the torque to slow you down and brakes fade rapidly.

[xrvr]

It would be useful for posters to mention the year of the tv. Towhaul, exhaust brakes, etc vary greatly from year to year model to model. My 06 dodge has a tow haul that does no more than adjust shift points, has no engine brake and only a four speed tranny. The new vehicles are way ahead of just a few years ago, for the better, but referring to the new systems and their use can be confusing or even dangerous for older tv when referring to downhill braking. On downhills I shift out of overdrive and slow down well before starting down, but use of the tv brakes is absolutely necessary. Even downshifting again is not enough for not having to use the tv brakes. The exhaust brake feature and the new tow haul mode on the newer trucks is fanrastic.

[SeaLevel]

2015 Chevy Silverado 1500 LT with grade braking. This 5.3L V8 has plenty of torque to slow us down. We drove this past summer in some 8-9% downhill grades and I only had to touch the brakes briefly a few times. I really only did that to make sure they were working, and to slow slightly before some turns. I was impressed with how well the grade braking works.

[xrvr]

Did you use tow haul and does it include some kind of engine braking?

[SeaLevel]

Originally Posted by avionstream

Did you use tow haul and does it include some kind of engine braking?

If that question was directed at me, yes, I always tow in tow/haul mode, and the grade braking I mentioned does work both in and out of tow/haul mode.

[xrvr]

Sea level, thanks, all this newer stuff amazes me..

[JCWDCW]

Those of us who only have gas engines seem to do just fine with out exhaust braking. I remember my first big down hill...nearly stopped the truck to put it in 2nd gear. Didn't need to... While there are some nasty switchbacks that need really slow speeds, I have yet to find a downhill that requires me to go down to the gear that I needed to get up. I don't believe I've ever applied brakes more than twice on a long down grade, including some twisty ones. Certainly do know that I have a second gear if I need it!! I just start out slow....sometimes because that's my speed when I got to the top, sometimes because it is the reasonable thing to do.
JCW

[TouringDan]

Originally Posted by Boxite

Keep in-mind that while travelling down-hill, even with engine-braking in lower gears...the trailer is trying to "push" the Tow Vehicle. Going straight doesn't pose too great a problem.
But...When a curve comes up, the trailer tries to push the rear axle of the TV to the outside of the curve. All you need now is a little loss of traction on those TV rear wheels and you've got a really nice jack-knife/roll-over possibility.

It might be helpful to remember that entering a downhill curve might be a good time to consider a little application of trailer-braking if things get dicey, and going downhill in wet-weather is a really bad idea if it can be avoided.

I should add that I plan to replace the OEM drum brakes as soon as possible with disc brakes to avoid the drum brake's tendency toward heating and fading.

Boxite

Thanks for pointing this out. I had never really thought about it but you are exactly correct. I will now make sure that I stretch the tv/trailer connection by using the trailer brakes when I am going downhill in a turn.

I also plan on ditching the antique trailer drum brakes and changing to disc brakes.

Thanks again Boxite!

Dan

[Castaway]

The Tow/Haul on our 2014 Ram 1500 does all the work for us, it seems like if the speed gets to fast the truck shifts to a lower gear and will change back when needed. I do use the brakes when a curve is coming up and the speed is to fast for me.


Gary

[slowmover]

Braking for a long descent is primarily a speed chosen to keep the transmission out of overdrive (there may be two, even three of these gears today), AND a speed target which is easy to re-acquire after exceeding it. Usually the gear below Direct is the first one to choose barring further experience.

The gear chosen should be long enough to provide sufficient rpm to do the following (as there should be no gear changes until at the bottom):

Say one is using 35-mph as target. Once nearing forty, one uses the brakes of the combined vehicle to bring speed back down to 30-mph. And then allowing the brakes to cool as the rig continues the descent. Preferably the rise in speed isn't rapid. If it is, slow to a lower speed and lower gear. Do this while the brakes are fresh.

Not all grades are the same. One may be warned a 7% downgrade is ahead, but in fact only a stretch of it is that steep. So, don't go thinking that the next 7-percenter miles down the road is as easy. And if one hits that sharp decline with hot brakes, there may not be enough left to hold her back. (Last I heard the state will send you a bill for about $20,000 for a runaway ramp restoration). You young pups ain't had much fun without experiencing loss of brakes in the bias ply tires + drum brakes all around good old days.

What residual brakes remained depended on a slow descent. One has to get off the road, right then.

There's no substitute for best brake performance (lightest TV with big disc brakes plus discs on trailer; hint, it ain't a one ton).

Someone else brought up curves. Yes, the trailer is going to push the RV to the outside. I've been pushed completely off the road in an 84k oil field semi-truck by a downhill short sharp turn. In the flatlands of South Texas. A minor rain had changed yesterday's easy drive into an embarrassing slide today when the clay surface was wet. Sure, I was slow . . . but not near slow enough as I thought 8-mph was good. Engaged the second drive axle and then locked the differentials to crawl out. (I was later told at least 20 other trucks slid off that morning).

As to big trucks: the (really) old road down Berthoud Pass was a truck graveyard. They'd bring up the bodies. Usually.

Also mentioned above was making the ascent at high speed. Bad idea. There's always someone else having to slow. Running up behind them or next to them isn't wise. Lack of space. In the same way, an sustained engine load above 75-80% just burns fuel and heats things up for no good return. There'll be plenty of heat to shed on the way down in any event. Speed up the hill isn't any more relevant to flat land travel speed than speed down the hill. Break the hypnosis. Speed limit signs have no meaning in themselves.

Proper gear choice. Short use of combined brakes to reacquire target speed. Plenty of brake remaining to keep distance from others AND to be able to slam trailer brakes AND accelerate TV simultaneously to correct trailer sway.

There's no passage or vehicle more vulnerable to a loss of control accident than a rig like ours on a mountain descent. Hitch in compression is Russian Roulette.

Now let's add some wind gusts. (Their source won't matter).

Good luck

[Dan and Liz]

Didn't notice anyone saying it before: brake BEFORE a curve to get your speed down; avoid braking IN a curve.

[JCWDCW]

Originally Posted by Dan and Liz

Didn't notice anyone saying it before: brake BEFORE a curve to get your speed down; avoid braking IN a curve.

This is absolutely correct. There is only a finite amount of friction resistance where the rubber meets the road. If some of it is being used to overcome lateral forces in a curve, there is less available for longitudinal braking force.

This applies equally to exhaust braking acting on the drive wheels in a tight curve.
JCW

[slowmover]

One should already have that habit in driving solo.


1990 35' Silver Streak
2004 555 Cummins

[Boxite]

Originally Posted by Holy Grail

There's nothing that compares to a diesel TV with a tow/haul function on along with an exhaust braking system. Anything else in the Rockies is extremely dangerous. Gas engines lack the torque to slow you down and brakes fade rapidly.

Reference to torque applies very little to engine braking, and the brakes you denigrate are similar regardless of engine choice as they are sized in accordance to vehicle wt. ...not engine.

"Anything else (other than diesel) in the Rockies is extremely dangerous."
= r
e
a
l
l
y.....

That's silly.

[Holy Grail]

I'm really not denigrating anything. I used a Dodge Hemi 1500 to tow my Flying Cloud 28 over the Rockies and there were moments I wasn't sure I'd make it. I upgraded to a Dodge 2500 Turbo Cummins with an Exhaust Brake and it was a major improvement!

[Gneiss Guy]

Originally Posted by Holy Grail

There's nothing that compares to a diesel TV with a tow/haul function on along with an exhaust braking system. Anything else in the Rockies is extremely dangerous. Gas engines lack the torque to slow you down and brakes fade rapidly.

Congratulation on owning a diesel TV. I'm sure it's a wonderful truck and I'm glad you are happy with it. This doesn't mean folks who arrived at a different decision are idiots. I have ownd a variety of trailers, all pulled by gasoline-powered trucks, and negotiated most paved passes in the Rockies with no problem. A diesel truck is a poor substitute for a little common sense and experience.

[n2916s]

Been towing my 31' Sovereign from Miami to Yellowstone every summer for the past 8 years with a 2004 Nissan Titan. There was never a moment in the mountains that I felt the least bit that I was in danger or that my rig was inadequate.

3rd gear, 3500 RPM zips me right up the grades at 60 mph without the temp gauges budging a millimeter.

Down is simply a matter of managing inertia. Engine braking, correct brake application, moderate speed.

Nothing dangerous about it.

[Dan and Liz]

Diesels are nice. My F150 works fine, both up and down.