downhill caused flaming brake pads!!
 

Did a pull from Az to OR yesterday. All went pretty well except coming downhill after crossing the border into Or, a 3 mile or so downhill 6% Ipulled over becuase the pedal was getting soft. Got out because I saw a glow, and the rotors were bright red, then the pad ignited!! A quick burst with the fire ext. about 20 min of sitting there, all seemed well. No fire damage to anything. But my questions are: Is the fire ext powder toxic or caustic? The pedal now seems to hang on a sec or 2 after I take my foot the brakes now. Also what about upgrades, or a way to use an exhaust brake or something with an auto? I was towing heavy too. 14540 GCWR. It seems the 4.10 and manual trans allow a higher trailer weight rating. Truck performed great other than that. I am now leary of any downhill grade now and I have to make this same drive at least 3 more times. 1 trip will have my wife and daughter on board! :( I didnt think it was that heavy starting out. Decided to get it weighed just to see. I am still searching this site for brake upgrades, but anyone knows some quick links? HELP!!! TIA


Bob

If the brakes got hot enough to burst into flame, I'd be thinking that the seals in the calipers were pretty much shot.

In order to run an exhaust brake with an Auto trans, there are some mods that will be necessary. ($$$)


Ed;)

What are the 1 ton wheel cylinders in your sig?
That sounds like you've already done some brake upgrades.

You could rig up a lock up switch for the torque converter that will allow you to use an exhaust brake.

But-

The stock torque converter won't be able to handle it very long and you'll be putting some $$$ into it quite soon.

Any of the aftermarket tranny companies can get you set up with something that can handle an exhaust brake, again much $$$.


I'm surprised you didn't lose your breaks entirely with them getting that hot.


phox

Yip first mod to the truck was the rear wheel cylinders. The front rotors were glowing bright red. enough to cast a shadow of the wheel on the ground. Had to work to get it to stop. The rears were toasty also. I set the parking brake since I was on a hill and that pedal almost went to the floor also. So I just blocked the wheels instead, incase the shoes might have locked on. I never saw brakes that hot on a truck. I felt the brakes start going soft so I pulled over and withing the last couple feet I saw the shadow start. I am glad I got it stopped. Now a dumb question is should I try to rebuild the calipers of just get new/reman ones?

I wouldn't bother with those calipers, get new/ reman. instead. Along with pads, rotors, final brake lines, and new shoes,drums and hardware for the back if they got that hot.

Not to be a prick or anything, but it's very possible your driving technique, and not a problem with the vehicle had alot to do with your flaming brakes... Though I *am* glad that no one was hurt...

I can say with absolute certainty that dry chem fire extinguishing agent is some naaaaaaaasty stuff... You might wind up buying new rotors, too.

Be honest, we're not gonna flame you (no pun intended), but were you riding the brakes to maintain your speed down the hill?

You have to with our computer controlled engines and trannies.

As soon as you let of the go pedal, the engine drops to idle speed, no engine braking whatsoever.

I've found if you lock out OD, the converter stays locked up longer, allowing some engine braking, but you have to be going under 55-60mph to lock it out.


phox

Big trailers require big trailer brakes. Sounds like you may be relying on the truck brakes too much.

That would have been my question. Were your trailer brakes functioning properly?

You may want to change brake fluid. If the brakes got that hot, you may have boiled the brake fluid.

Rich

I don't see where anyone has mentioned wheel bearings. At least on the 2WD trucks, if the brakes got that hot, the front wheel bearings are probably toast! :(

Stories like this make me glad I have the Jacobs e-brake! :)

Rusty

Not to flame but if I had to use my brakes hard enough that they got that hot I would figured have some thing was wrong and pulled over long before they got hot enough to start on fire. You're just lucky you had a place to pull over instead of barreling down the mountain possibly causing an accident.

I was always taught to lay on the brakes to get 10mph below your target speed... then release... the speed builds back up, then you lay back on 'em again, repeat...

14500 combined isn't that heavy for these trucks, and I have driven nearly the same weight (it was about 13,500 combined) with a much lesser vehicle (1/2 ton) down a long 6% grade with curves, and got little to no brake fade, and certainly no fire using that method. Yes, the trailer did have brakes (one axle)...

Honestly, I don't wanna come across as a know-it-all or a jerk, just really trying to help the guy.

I can only assume that on my trip, we started at the top of the hill at a slower speed than Bob did...

Anyway, since you didn't ask for a critique on your towing ;) certainly replace the calipers, you very well may need new rotors (we did on the race car), check the wheel bearings, and give the fluid a good flushing when you replace the calipers.

Our brakes did the same thing after being hit with dry chem... you could feel the stuff that had baked onto the brake rotor with your fingers, felt like a sticky goo that just wouldn't come off.

I wonder if he had operational trailer brakes? and if he did.....maybe the connection harness came loose or broke? Only way to burn up the trucks pads (other than riding the brakes) was if there was no trailer brakes.

Ok My responses:
The trailers brakes were functioning. I even turned them up all the way during the desent. My driving technique, I know not to ride the brakes, so I would slow down to about 50 then let it coast up to about 70-75, then on the brakes again. I had OD locked out. (I didnt know it kept the converter locked. I did noticed that it seemed to allow some engine braking.) A typo on the weight it was 19540 GCWR [eyecrazy] I was worried about the bearings also, along with the brake fluid. So prolly new rotors calipers and bearings. After I got it all stopped all the brakes were hot. The rear drums were radiating a lot of heat, as were the trailer brakes. It is a triple axle trailer with all 3 having brakes. When I realized how quick the trailer would push the truck on a 6% I got worried. I have never towed this much weight before. I really didnt think I had that much weight. I am not loading that heavy again. At least not without a manual and exhaust brake. So would all new parts be the best option being how hot everything got? I need to make about 3 more trips loaded. (just not as loaded next time :eek: ) I'm sure my driving technique might have had something to do with it :) but I didnt know how to keep the truck slowed so I just slowed it down then let it coast back up. Any advice will be helpful. Like I said I might even make an extra trip empty just for the family. I dont want this to happen with my most precioius cargo on board. Thanks again everyone. tomorrow I will probably start tearing into the breaks. I pulled into town 1.5 hours before I had to be at work! Long haul from LA to portland in one day. [eyecrazy]