Q: I have a strange problem with my 1986 Carrera. After I turn a corner, I notice that my brake pedal drops very low. This is very disconcerting. As soon as I straighten the wheel and apply the brakes, the pedal feels normal again. I have flushed the brake fluid and taken it all apart twice! I rechecked everything I replaced: the front wheel bearings, rotors, and brake pads. I am tearing my hair out. – Heavy
A: Strange is an excellent word for this. My guess is that turning and loading the front wheel bearings pushes the brake pads away from the rotor. I have run into this and been annoyed by it myself. You can actually install incorrect wheel bearings if you don’t compare them. Bearing sets can have the correct outside diameter but a larger inside diameter. Even though bearing preload is correctly adjusted, the bearing can “act” loose when turning. Cornering forces generate strong side loads. This allows the inner bearings to “walk” out of place, and rotor deflection pushes the brake pads away from the rotor. During straight line driving and braking, the wheel hub will stay centered since there are no “side loads” (and the brake pads stay close to the rotors”). Crazy.
A 1967 Beetle schooled me on this topic. The lesson: compare parts. A late night Detroit DJ used to sign off at night with: “Remember, trust everyone…but always cut the cards”. I considered my experience just another tuition payment. Good luck. – MC