Let’s finish this brake week with a collection of failed disc brakes.
Similar to the brake shoes in my last post, the adhesive or bonding of the friction material to the metal backing of these brake pads failed, and a section of pad slid out and was rubbing against the center of the rotor.
On the rear of the same car some of the pads had started sticking in the areas they’re supposed to slide. Could be from lack of lubricant or just age. In this picture, the pad on the left is crooked.
These are all the pads I took off that car. You can see all the pieces of friction material that were coming off. The smaller pads are from the rear, and you can see that they got crooked and unevenly worn, one even starting to wear into the metal.
On the top is a brand new brake pad, so you can see how worn down these brakes are. The one on the left is very close to gone, but the one on the right wore through all the material down to the metal. Usually we recommend replacing brakes before they get all the way down to the metal, so you always have properly functioning brakes. Metal on metal doesn’t work nearly as well, and in New York it’s illegal.
Another pad that got crooked for some reason, wearing at a slant and into the metal backing.
Four-piston brakes are notorious for failures. Every time I went to recommend new pads and rotors I would make sure to try to push all the pistons back in to make sure none were seized. This caliper was fine, but the pads had gotten stuck, causing the one on the right to wear all the way down.
This is one with at least one seized piston. It would push out when the brake pedal was pressed, but wouldn’t go back in, causing the pad to continue to press against the rotor on that side, and wearing it very unevenly.
It looks like this must be a total failure of the caliper piston to even push outwards. The rotor is completely rusted. When you use your brakes it keeps them clean and free of rust, but this one obviously hadn’t been having the brake pads rub against it at all, so it just rusted up.