1991 Toyota Corolla Brakes intermittently engage without us

1991 TOYOTA COROLLA
175,000 MILES • 4 CYL • 2WD • AUTOMATIC
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WRIGHTWX
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  • 1 POST
Sometimes my brakes engage themselves when I am driving. They will not fully engage, but partially, causing me to have to increase pressure on the accelerator so the car does not slow down. Sometimes they are already engaged when I first start the car up in the morning and sometimes they are fine, then randomly engage while I am driving. I can feel the tightness in the brake pedal when they are doing this. When not engaged, the pedal action feels softer. I have had the brake pads changed and the brake fluid flushed by a shop. In their words: "We don't know what is causing it." What is causing it and how do I fix it?
May 14, 2008 at 2:50 PM
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MMPRINCE4000
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The only thing I could think of is the booster is malfunctioning, somehow pushing the master cylinder rod (assuming the brakes are installed properly and the parking brakes and cable are functioning).

Also make sure you are not confusing the brakes with the transmission differential (which uses a seperate lubricant supply) and the differential is partially seizing. Check the differential fluid level.
May 15, 2008 at 7:39 AM