Question about 2021 Chevy Silverado 2500HD Brake Controller

[LJS1211]

Two weeks ago I upgraded trucks and purchased a 2021 Chevy Silverado 2500HD Duramax. Today was the first time towing our 30ft International Serenity 30RB. The truck was a beast and definitely pulled a lot better than our previous gasser and the best miles per gallon I’ve seen for us anyways. The new cameras and trailer apps were also a welcome addition.

The only question/concern I have is with the integrated brake controller. Went through my normal checklist and last thing I did was squeeze the controller to make sure is was working and while yes it engaged the trailer brakes it seemed like it barely did. So I bumped it all the way up to 10 and same results. So I put it back down to 5 and we got on the road.

I’m fairly confident the brakes are working but even turned up to 10 it just didn’t seem like the trailer was grabbing us like the old truck did. Curious what level others have their controller set at and if anyone has experienced anything similar to this. Thanks in advance.

[Al U. Minium]

Duramax even idling pulls harder than your gas motor did. Kick it in neutral when you are rolling forward, hit the controller brakes and see if it doesn't grab harder. Assuming you had a gas truck before since your mileage is up.

I have gas 2500 and same trailer, and yeah, trailer brakes will grab hard on the truck when I do a quick test before hitting the road.

Just as data point I run the onboard controller around 4.5 points.

P.S. Nice truck. What's the payload on it with diesel?

[LeatherDog]

We have a 2020 GMC 2500HD. Integrated brake controller setting 3 to 3.5. 4 locks up the wheels instantly. If you go to 10 and the brakes are not locking up, something is wrong somewhere. I would pull the break-away switch and see, in a parking lot, if the wheels are at least locked at low speeds.

[LJS1211]

Originally Posted by Al U. Minium

Duramax even idling pulls harder than your gas motor did. Kick it in neutral when you are rolling forward, hit the controller brakes and see if it doesn't grab harder. Assuming you had a gas truck before since your mileage is up.

I have gas 2500 and same trailer, and yeah, trailer brakes will grab hard on the truck when I do a quick test before hitting the road.

Just as data point I run the onboard controller around 4.5 points.

P.S. Nice truck. What's the payload on it with diesel?

Thanks for the info. Here’s a picture of the sticker from the truck to show you payload capacity

[LJS1211]

Originally Posted by LeatherDog

We have a 2020 GMC 2500HD. Integrated brake controller setting 3 to 3.5. 4 locks up the wheels instantly. If you go to 10 and the brakes are not locking up, something is wrong somewhere. I would pull the break-away switch and see, in a parking lot, if the wheels are at least locked at low speeds.

Thanks I will try that and see what happens.

[jaybauman]

Originally Posted by Al U. Minium

P.S. Nice truck. What's the payload on it with diesel?

GM gives the Duramax models a higher GVWR than the gasoline variants, so the diesel payload penalty is not really a thing anymore. I don't know if Ram and Ford have yet followed suit.

[Skillet]

25’ International

[Life is a Highway]

Try it coasting in neutral at 10 mph I set our Ford F-250 diesel 4.5-5

I will say our new trailer took a few miles for the drum brakes to seat in. At first I felt very little braking after 15k it was felt

[Atwebs]

Our 2019 Silverado Diesel 2500 has the brakes set at 5-6 and it works great (2129 GT 27). You are going to love the new combination! We get about 14 mpg when towing and more when we aren't, plus the truck is so comfortable and quiet. The best thing is that we always have enough power and the air brake adds even more control to the entire set up when you are going downhill. Congratulations!

[GCinSC2]

Joey,

You might have done this (setup) but I didn't see it in your original post.

Can you go into the setup for the ITBC and review the settings you are using.

Any chance to post a clear closeup pic of the trailer plug end? Showing the terminals and condition.

Pic of the plug connected into the trucks 7 way?

Gary

[Warrenwhite]

We purchased a 2020 Duramax 2500HD last August to pull our 27' International FB. I have has a few issues with the tires locking up and leaving skid marks on the road at a gain setting of 6.5. I lowered it to 4.5 and seems ok. Now I am wondering if that is too low. We are newbies both to driving a truck and pulling a TT. Appreciate all the suggestions and comments in the forum.

Warren White

2021 International FBT
2020 Chevy Duramax 2500HD

[jaybauman]

Originally Posted by Warrenwhite

We purchased a 2020 Duramax 2500HD last August to pull our 27' International FB. I have has a few issues with the tires locking up and leaving skid marks on the road at a gain setting of 6.5. I lowered it to 4.5 and seems ok. Now I am wondering if that is too low. We are newbies both to driving a truck and pulling a TT. Appreciate all the suggestions and comments in the forum.

I found a gain of 5.5 worked just about perfectly for a 2020 Duramax 3500HD pulling a 2019 Flying Cloud 30 Bunk. The trailer didn't stop itself with less gain, and the brakes would lock up with more.

[Al U. Minium]

Originally Posted by Joey Stryk

Thanks for the info. Here’s a picture of the sticker from the truck to show you payload capacity

Yeah, that's a great payload for a diesel. My 2500 2015 is 3322 lbs and it is a double cab 2wd gas truck.

Good luck on getting your trailer brakes sorted out there's some good tips in this thread.