My newly acquired '08 Pacifica has the type of wheel that allows me to see the rotor, and I also can just get a peek at the brake pad. I was able to measure it (i.e., from the rotor surface to metal block that the pad is mounted on) at about 3/16" (~4.7mm). It then occurred to me that I have no idea if that's good or bad. The rotors are smooth and beautiful, so I know they're not worn out at the moment, and I don't hear any sort of wear-indicator brushing noises. I have no service history on the vehicle and I don't want to risk driving on worn pads. Should I worry?

 

Pull the wheels off and "INSPECT" the brake pads.

The problem with what you propose, is this...You Cannot See the INNER pads.

Now having said that.... Industry standard measurements are taken in 32nds of an Inch. Which in your case would be 6. Typicallyt, pads start their life at approximately 12/32nds....All else being equal, and Inner pads even with outers, You have worn out Half of your pads. The wear sensors make contact between 2 and 3 , which is MORE THAN ENOUGH time for you to address the noise issue when it arises.

 

Thanks, D-n-T, you saved me the cost and irritation of an extra trip to the dealer.