03 Escalade rear brakes run at 260-300 degrees farenheit during normal use driving to work on secondary roads with 45 mph speed limit. Is that normal?

[Curlyface]

03 Escalade rear brake rotors run at 260-300 degrees farenheit during normal driving to work on secondary roads with 45 mph speed limit for 35 minutes. The front brake rotors run at 140 degrees during the drive. I have replaced rear pads, calipers and brake hoses as well as checking the caliper mount pins to ensure they were not stuck. After those repairs failed to bring the rear temp down I replaced the abs module (computer) and modulator valve but the rear still runs at the 260-300 temp. I then replaced the master cylinder but no temp reduction. I also considered the e- brake and checked it to find it is operating correctly. I have since been told this model runs a higher rear brake temp, does anyone know what the temp should be under the above described conditions?

 

[rockola1971]

Do you have the emergency brakes setup correctly? Is your Ebrake hardware all there and not in pieces? Is it both rear wheels or just one?

 

[tom3]

I'd come to a stop on a slight upgrade in neutral, see if the brakes release enough for the machine to roll backwards. That sure seems hot for normal driving and light brake applications. I had a similar deal with our Blazer but the composite material caliper pistons were noted for that, replaced them and all was well. (I see that you've already done that) See any bluing on the discs?

 

[Donal]

Perform the test recommended by Tom3, twice, once cold and again when the brakes are hot as you mentioned in the first post.

 

[Curlyface]

So the composite pistons in the rear calipers cause over heating? Where did you find replacements that were not composite pistons? Do you know why the composite pistons cause overheating?

 

[Donal]

Refering to the parking brake as an "emergency brake," is incorrect as the term implies that the brake can be applied in emergency situations. These vehicles do not require an emergency brake system and do not have such. The parking brake, designed for these vehicles, is not capable of dissipating heat caused by emergency braking and can be damaged by such use. Below is directly quoted form the code section defineing requirements for these vehicles.

§ 393.41
The parking brake shall be capable of holding the vehicle or combination of vehicles stationary under any condition of loading in which it is found on a public road (free of ice and snow).