Solved Poor braking

[429CJ-3X2]

My '01 Sport Trac hasn't stopped well since I bought it over 6 years ago. I finally solved the issue. I replaced the rotors and pads on my '02 last winter and intended to do the same on the '01 this summer, which I did several weeks ago. The outside (visable) surface of both rotors was smooth and looked good. The inside surface was a COMPLETELY different story!

Only about 1" of contact between the pads and rotors. I replaced them with the same combo as I put on the '02 last winter - Wagner rotors and Motorcraft pads. The truck now stops like it should!

 

[RangerX]

What do you think caused that?

 

[Gary Crist]

What do you think caused that?

Heat sink on the inboard pad set. The inner is going to be hotter when driving.
The salt in the water breaks down into Na+Cl with heat. FeCl can then form some hard surfaces
that will not wear.

 

[429CJ-3X2]

My answer would be, I don't know. Gary's answer is better than anything I'd come up with. The pads looked every bit as bad as the rotors, and the rotors look worse in person than it shows in the photo. 1" of contact might be generous. Both rotors were rusty and badly grooved where they weren't making contact and the pads matched. The outside surface of both rotors were smooth and looked fine, as did the pads. I've had grooved rotors before, but the grooves weren't rusted like these.

I guess the lesson here is, don't rely on the appearance of the outside surface of the rotors. Check the backside too.

 

[Gary Crist]

One that I recall was a Ford Pinto in for 4 tires. One of the tire men called me over
to figure what was wrong with this rotor. The hub spun as the outer part of the rotor
stayed put (it is one piece)! The outer surface was fine w/ 3/4 pad left. The inside was
fins with the pad "kicked" in cutting the rotor in half at the hub.