Soft brake pedal and rear brakes get hot really fast

PHILLDIXON

MEMBER
2002 CHEVROLET SUBURBAN
5.3L
V8
4WD
AUTOMATIC
220,000 MILES

October of 2020 I lost brakes completely coming off a steep hill. The car has always had a soft pedal so this spring I replaced the master, all 4 rotors, pads and one caliper. Now it seems there is more stopping force in the rear of the car and the brakes get hot enough to smell in a fairly short distance, especially going down hill. Could it be a proportioning valve problem? I am out of ideas on how to fix this thing. Again, pedal is softer than I think it should be and the rear brakes get hot real fast. The car is disc all the way around. No lights on the dash and as far as I can tell the rear calipers are not stuck.

1 Reply

KASEKENNY

MECHANIC
18,907 POSTS

Your vehicle does not use a proportioning valve so we need to try and narrow this down to another possible cause.

https://www.2carpros.com/articles/how-to-replace-rear-brake-pads-and-rotors

I suspect the issue by be a rubber line heading to the caliper but this is unlikely that both would have failed at the same time.

So if all this happened after the master cylinder then you may have a faulty master that is holding the caliper partially applied.

However, I would start with checking the rubber lines by holding them and having someone apply the brakes. If the line swells then more then likely it is failed and needs replaced. This actually will hold the caliper partially applied.

I would also do two things. Lift the rear of the vehicle and put it on jack stands and then spin the wheel and use the brakes. Then keep them applied for a few seconds and release the brake. Then see if the tires spin freely.

https://www.2carpros.com/articles/jack-up-and-lift-your-car-safely

Next use a laser temperature meter to find out how much hotter the rear are then the front.

https://www.2carpros.com/articles/how-to-use-an-infrared-temperature-meter

Let's run through this material and let me know if you have questions on this.

Thanks

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