2009 Ford Flex: That Grinding Feeling
August 17, 2010
Mike Schmidt brought our 2009 Ford Flex back from Napa yesterday morning (the wine-growing region, not the auto parts store), looked me straight in the eye and said "your new brakes are grinding."
To be honest, he said "the brakes" but I knew I was the last one to tear them apart, so I self-supplied the "your" part.
Yes, I recently put new front brakes on our 2009 Ford Flex, but two long road trips in rapid succession means they already have over 4,000 miles on them. I finished the job one day before Josh left on his road trip to Wyoming. As soon as he returned, Mike headed north on another long drive. Our Flex is in high demand.
I am happy to report that I didn't screw up. Those new front brakes are working great and keeping quiet.
However, Mike was right, too. This morning I confirmed the deep grinding noise he heard when slowing at parking lot speeds, and it is brakes. Happily, for me, the noise is coming from the rear of the car.
In the above photo, you're seeing the following in thin geologic slices, left to right: rubber piston boot, piston face (notched), inner pad backing plate, rotor (rust-colored), outer pad friction material, outer pad backing plate, caliper fingers. What's missing? The inner pad friction material, that's what. From another angle I can see that there is some, so I don't think we're quite at the metal-to-metal stage, but what's visible amounts to far less than 1 millimeter.
So if I'm guilty of anything it's failing to check the rear brakes while I was working on the front ones. They don't often wear out at the same time, like smoke detector batteries can, but a quick look at the other end is always a good idea.
You know what this means, don't you? That's right, a rear brake pad and rotor replacement DIY post is around the corner.
Dan Edmunds, Director of Vehicle Testing at 66,169 miles