Question about Grade Braking/Exhaust Brake Interaction

[richp]

Hi,

No action in the Towing section, so I'll try here...

So I broke weak and bought a leftover 2019 Dmax crew cab to tow with. There is lots to learn about a truck that has ten years of upgrades and new features over my old 2009.

But in particular, would anyone towing with a similar rig give me a tutorial on how these two new-to-me features interact in actual use.

Thanks in advance.

[rapidoxidationman]

I know I'm being Captain Obvious, but have you read the owner's manual? If yours somehow didn't come with one, it can be found here:
https://my.chevrolet.com/how-to-support

[richp]

Hi rapidguy,

Yup, I did. But I was hoping to get some "actual use" input, hopefully from someone towing a 12k+ trailer -- even better if it involved some really long grades, like in the Rockies.

Rich

[richp]

Hi,

Wow, all these hugely capable towing machines (L5Ps in particular) out there and nobody has any experience to report on actual tow/haul, grade braking, and exhaust brake functioning while travelling with big trailers?

[DmaxMaverick]

What is it you want to know? A "tutorial", I think, isn't really relevant, as there are too many variables involved, unique to each owner and condition. I don't have one, and only know of a few. From what I gathered, it isn't really anything worth much discussion, and comments are essentially, "it really works". The systems are simple. They don't necessarily "interact", but compliment each other. The features are independent, and the only "interaction" is the PCM control that prevents them from conflicting. Grade braking is transmission control, much like it has been since the 2001 M/Y, and the exhaust brake is only a means of increasing resistance during compression braking. It's only that simple, and it works as advertised. Anecdotally, as related to me, 24K is easily held @ 35-40 MPH for several miles of a 6+% grade (N/B I-5 Grapevine) with occasional, minimal service braking. Basically, unremarkable.

[richp]

Hi Dmax,

Yeah, tutorial was probably the wrong word, but your explanation helps. If I get it right, I just turn on all three and let it rip. That is no way clear from the GM material.

But I suppose I still was hoping to hear from someone who is actually using their truck in heavy towing situations, for a description of performance.

[N9Phil]

When you are interested in something I find the first thing to try is a Google search. If you do a Google search on "Exhaust Brake Interaction" I think you will find everything that you need.

[richp]

Hi Phil,

Did that early on, and again just now. Those results address either generic exhaust brake operation or installation.

Ironically, since my first search a while back, an additional item has appeared -- a link to this thread on the Diesel Page Forum.

[Kennedy]

The grade braking is not much different from the older trucks. The exhaust brake just makes it MUCH more effective.


If you are towing enable the exhaust brake and let it do it's thing. If the truck is still gaining speed on a descent cover the brakes so the truck sees you wanting to slow and it will drop another gear increasing the retarding force.