I have a 03 Escalade 6.0 liter with hydroboost that is engaging the rear brakes during normal driving, when the pedal is not being depressed. I have done all of the usual work, such as replace calipers and brake hoses. When the usual repairs failed to alleviate my problems I went much further, replacing the ABS module, ABS modulator, master cylinder, rear wheel speed sensors and disconnected the yaw sensor sensor. I am out of ideas and wondering if it is possible for the hydroboost to be causing this problem. Any help would be greatly appreciated!!!!
Rear brakes wear out prematurely/overheat
- Thread starter Curlyface
- Start date
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How do you know they’re engaging while driving without pressing the pedal? FYI the NBS SUV’s are known to wear the rear pads out faster than the front for some unknown reason. You might not even have a problem.
There is also such thing as a proportioning valve which determines proper front/ rear braking proportions but I don’t think I’ve ever heard of one going bad on these. But since you have the parts cannon out:
There is also such thing as a proportioning valve which determines proper front/ rear braking proportions but I don’t think I’ve ever heard of one going bad on these. But since you have the parts cannon out:
2003 CADILLAC ESCALADE 6.0L V8 Proportioning Valve | RockAuto
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tom3
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I'd start with a cheap IR temp and see if the rotors are getting hot after a drive. Does the emer. brake use the pads? Could be that's not releasing completely?
I have to assume the rear brakes are engaging without the pedal being depressed since they are running very hot after a short period, say 20 minutes of pretty easy driving. I havent actually measured the temp yet but after 20 minutes of driving the rear wheels are too hot to touch but if I jack the rear up the wheels turn easily by hand. I thought about the proportioning valve but didn't replace it since it didn't seem plausible, at least to me. On this truck the proportioning valve is mounted between the pre-charge pump and master cylinder so since it is "in front of" the master I didn't think it could cause these symptoms. Do you think I may be wrong?
The purpose of the proportioning valve afaik is to set the proportion of front to rear brake bias. I don’t see how the rear rotors are getting hot if the wheels spin freely when it’s on jack stands. Have you started the engine while it’s off the ground and tried to turn the rear wheels? I’d be curious to know the actual rear and front rotor temps. An IR thermometer can be had for cheap at Harbor Freight.
rockola1971
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Emergency brake on our generation uses a brake shoe shape like a C. Thats why our rear brake rotors are tophats instead of the stereotypical flat rotors. Emergency is independent of service brakes.
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swathdiver
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That was the first repair made on my '79 Buick as a kid! Only one I ever had a problem with.
rockola1971
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I had a 85 s-10 blazer 4x4 crack a proportional valve when I was stationed in Norfolk. It of course leaked every time you pushed the brakes and sucked in air when you released.
Donal
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Have you removed the disc and inspected the parking brake components? I have seen several where the parking band had damage and parts were just in there loose or in the wrong place.
Any updates @Curlyface ?
