Front brakes stink after long downhill

[DaveO9]

I'm a scoutmaster and I was with our troop last week at summer camp. I hauled our troop gear trailer which I'm guessing is about 3K lbs loaded. Camp is 5 miles off the highway and about 1500-2000 feet of elevation gain over that distance. On the way down I had burnt smelling brakes in front by the time I got to the highway. I could smell them in the cab, and driver behind me could too. No brake judder at all, no unusual noise, braking performance stayed consistent. No issues the rest of the way home either.

This has happened twice before: once after a long descent in Death Valley, but I was not pulling a trailer that time and it was not super hot (in November). I installed new semi-metallic brake pads after that trip. Then another time pulling the same scout trailer down a similar long, steep, slow grade.

Thoughts? Sticking calipers only when hot? Replace or turn rotors?

 

[OR VietVet]

Do you ride the brakes or feather them with transmission shifted to a lower gear? I was taught by truckers that low gear and when needed, apply brakes fairly hard and slow below the speed limit and then release brakes and let them cool and breathe till next time that you apply brakes again. Always worked for me.

 

[DaveO9]

Do you ride the brakes or feather them with transmission shifted to a lower gear? I was taught by truckers that low gear and when needed, apply brakes fairly hard and slow below the speed limit and then release brakes and let them cool and breathe till next time that you apply brakes again. Always worked for me.

I forgot to mention some of that stuff. I was consciously trying not to ride the brakes - letting off completely when I could to allow some cooling. I also kept it in third most of the time, even down to second in some cases. I was not using tow/haul but in retrospect I think I should have - seems to give even more engine braking then just manually downshifting.

 

[OR VietVet]

Yea, I should have asked about that. That tow/haul mode is there for a reason. Let the A.I. mode take over and do what it is supposed to do.

 

[swathdiver]

I'm a scoutmaster and I was with our troop last week at summer camp. I hauled our troop gear trailer which I'm guessing is about 3K lbs loaded. Camp is 5 miles off the highway and about 1500-2000 feet of elevation gain over that distance. On the way down I had burnt smelling brakes in front by the time I got to the highway. I could smell them in the cab, and driver behind me could too. No brake judder at all, no unusual noise, braking performance stayed consistent. No issues the rest of the way home either.

This has happened twice before: once after a long descent in Death Valley, but I was not pulling a trailer that time and it was not super hot (in November). I installed new semi-metallic brake pads after that trip. Then another time pulling the same scout trailer down a similar long, steep, slow grade.

Thoughts? Sticking calipers only when hot? Replace or turn rotors?

The way I'm reading this is that your trailer doesn't have brakes. It ought to.

You don't need Tow/Haul mode for normal operation with that light of trailer but it might help going down those grades. Same with range selection mode.

I once suddenly found myself going down steep grades in a suburb of Atlanta. At first I tried tow/haul mode but if memory serves, use range select for faster control and of course judicious use of the brakes. We weren't towing either!

My daughter got her brakes smelling going down 191 between Jackson and Rock Springs, she was flying down the highway in her newly purchased truck at 80 mph. She called and got some advice and made it down. 60K+ miles later, those pads are still on the truck.

 

[j91z28d1]

when you replaced the brakes, did you do the bed in progress? if not, this is the first time they have been used hard. I wouldn't worry about just a smell, if the pedal didn't get soft and you were towing down hill it's reasonable to get some heat in them.

if you did this every weekend, there's a HD brake option I see these guys talk about. but I don't feel like you have any real issue. brakes get hot the small bad.

I would in the future also bed in New pads. old guys used to call it letting the smoke out lol. but if your brakes didn't come with the instructions to follow, just Google for a general one.

 

[Charlie207]

You basically panic-brake from 40mph > 5mph (don't come to a complete stop) five or six times in a row, down a straight stretch of road.

I usually let the traffic behind me pass before bedding in my brake pads.

 

[Geotrash]

I'm a scoutmaster and I was with our troop last week at summer camp. I hauled our troop gear trailer which I'm guessing is about 3K lbs loaded. Camp is 5 miles off the highway and about 1500-2000 feet of elevation gain over that distance. On the way down I had burnt smelling brakes in front by the time I got to the highway. I could smell them in the cab, and driver behind me could too. No brake judder at all, no unusual noise, braking performance stayed consistent. No issues the rest of the way home either.

This has happened twice before: once after a long descent in Death Valley, but I was not pulling a trailer that time and it was not super hot (in November). I installed new semi-metallic brake pads after that trip. Then another time pulling the same scout trailer down a similar long, steep, slow grade.

Thoughts? Sticking calipers only when hot? Replace or turn rotors?

1500' in 5 miles is a 5.7% grade. 2000' is a 7.6% grade. Pretty steep. It's probably safe to assume that the grade wasn't consistent through that distance and that you likely had areas where the grade was much steeper. On a highway, the higher speeds give you a significant aerodynamic braking effect - especially pulling a trailer, which you won't have at lower speeds. So, a really steep grade plus low speeds creates the worst possible scenario for your brakes.

I pull a 7500 lb. camper with our Yukons and it has its own brakes, but our 3500 lb. (when loaded) single-axle cargo trailer does not. I pull both fully loaded over the spine of the Blue Ridge mountains fairly regularly with similar grades and a 35 mph speed limit. I use tow/haul mode and choose the gear and speeds appropriate for the conditions that require me to use the brakes only very rarely (sometimes it's 25-30mph in 2nd). When I'm down, if there is anyone stuck behind me I pull over and let them go by on the flat. Keeps my brakes from getting hot and lets them remain effective in case I need them for a panic stop. I have the factory-spec brakes on both Yukons.

When they start to smell, you're minutes away from losing most of their effectiveness. More importantly, I doubt there is anything wrong with your brakes. You just gave them one hell of a workout, as others have said.

 

[DaveO9]

Thanks all for the thoughts. No the cargo trailer doesn't have brakes. And yes, going pretty slow so little aerodynamic braking or cooling. Just going to be more careful in the future and use tow/haul more liberally. Also plan to do the brake pad bed-in procedure.

 

[Doubeleive]

Thanks all for the thoughts. No the cargo trailer doesn't have brakes. And yes, going pretty slow so little aerodynamic braking or cooling. Just going to be more careful in the future and use tow/haul more liberally. Also plan to do the brake pad bed-in procedure.

I use tow haul all the time when going down any kind of steep hill without towing anythng it helps a lot I am also a bit of a extremist while driving
even with upgraded 15" rotors I can heat the brakes up fairly easily.
I had mine smoking so much one time I thought they were going to catch on fire, the smell of hot brakes is unmistakable
I bet if you use the tow haul next time you won't have any issue, let the engine do the work it won't hurt anything it's designed that way on purpose.