Brakes pulsing with vehicle off?

[marin8703]

hey everyone,

Weirdest thing happened this mornig. As i went to the car and opened the hood to get ready to start changing my oil, i heard a quiet thumping sound. I narrowed in on the sound and it was right under the brake fluid reservoir, where the 4 little brake lines come out off.

The real crazy thing was that the truck was not started nor had it been for the past 8-10 hours. I hadnt even put the key in the ignition yet.

It thumps or pulses about once a second. I figure it was doing that all night, but how, without the ignition on or the key not even being put in; is ABS or TC active while vehicle is off and no key in???

Anyways once i put the key in and started it, then turned it off, it wasnt doing it anymore. I hope it doesnt do it again tomorow morning.

Have any of you people experienced this? Any idea why it may happen?

Thanks!