Brake fade for the first time

[Uncle Damo]

I've used this truck and trailer combo together about 6k miles over the last couple years with no issues whatsoever until yesterday. Towing my toyhauler loaded up to approx 8500#, and on a route I've towed multiple times. Was following another guy towing down a 10 minute curvy grade who was going slower than normal, so I may have been on the service brakes a bit more than usual, but was also manually using the trailer brakes as I normally do. Toward the bottom of the grade I started smelling the brakes, figured it was someone in front of me since my truck's never had any issues and this was not an extreme situation. Then the pedal got soft, and by the time we were at the bottom it took all my strength into the pedal to approach a stop. We stopped and let it cool for 5 minutes at the bottom and for the remainder of the trip on the flats the power and feel were back to normal, strong power and firm pedal feel.

A few months back I replaced the stock front rotors and pads since they were warped at 55k miles. Power and feel was always fine with the stockers. For replacements I used "Power Stop K2163-36 Front Z36 Truck & Tow Brake Kit, Carbon Fiber Ceramic Brake Pads and Drilled/Slotted Brake Rotors" which had very good reviews. Initial impressions, and first two tows with them were very impressive. Felt at least as good as stock and possibly a bit better power, no noise, no fade. I replaced the brakes myself and did not bleed them, something I've done many times in my life on different trucks.

So any thoughts on what may be the cause ? Poor pad compound for towing, may need a bleed, drilled/slotted rotors ? This is obviously a dangerous situation that could be a disaster on a more consequential grade, I won't tow again until it's addressed.

 

[crazykid1994]

After overheating you will definitely want to bleed the fluid to get fresh fluid in. You should bleed the fluid every few years anyways. A lot of people think the system is sealed which they are not and moisture can still enter the system and degrade the oil. I’m my experience any higher friction pad for better stopping will always create more heat under the same conditions so it’s a good idea to get rotors with increased cooling efficiency in circumstances where you are using higher stopping power.

 

[DC Tradesman]

I would make sure that one of the caliper pucks aren't retracting fully, it may be a faulty puck or pad return spring not installed correctly or failed.

 

[crash68]

next time don't use your brakes so much, force the transmission to downshift. Using your trailer brakes only cooks them too, then your relying on the truck brakes even more. just like climbing the grade, the engine is going rev up.

 

[csuder99]

"20" LRG rims with 35x12.5 Pro-Comps" - There is part of your problem, these tires are ~10% larger in diameter than the stock sizes. While that doesn't sound like a lot it ramps up the heat faster while the cooling is not any better.

 

[Rlaf75]

You overheated the brake fluid and more than likely glazed the pads. I would recommend flushing the brake fluid COMPLETELY to get all the old nasty broken down fluid out and replace it with fresh clean brake fluid. The brake fluid is probably the most overlooked item when serving your vehicles. It breaks down and gets contaminated and you get exactly what happened to you. When you completely flush the brake fluid I would also recommend looking at the brake pads to see how glazed they are. If pad is still at a safe usable thickness you can use a fine sandpaper to scuff up the surface to take the glaze out of them. Or replace them. Also look at the rotors for discoloration. If they got overheated, which I'm sure they did you'll see a purplish hotspots on the rotor surface. Most importantly though, get the fluid flushed

 

[Uncle Damo]

Thanks for the suggestions. I'm going to take the truck to a local brake specialist and have it all examined and the fluid changed. Just seemed strange to me that this same drive I've done many times, and in cool weather, just this trip showed a problem, the only difference being the new rotors and pads.

I'll report back afterward.

 

[Rlaf75]

Thanks for the suggestions. I'm going to take the truck to a local brake specialist and have it all examined and the fluid changed. Just seemed strange to me that this same drive I've done many times, and in cool weather, just this trip showed a problem, the only difference being the new rotors and pads.

I'll report back afterward.

The brake fluid breaks down over time and this time was the straw that broke the camel's back. If you look in your owners manual at the service intervals it will probably say to flush the brake fluid miles ago. Like I said in my previous comment, it's one of the most overlooked services that rarely gets done