2001 Cadillac Catera How do I know to change my brake pads

[quote="michelle scribner"]Brakes problem
2001 Cadillac Catera 6 cyl Two Wheel Drive Automatic 73565 miles
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I need to know when I should change the brake pads on my 2001 Cadillac catera. I have all receiptsa to the car and none of which say a brake job was done. I bought the car less than a year ago. I can't really tell.[/quot

you have an indicator lite when pads need to be done( brake pad sensors )