1. Brake judder concern has the following 3 characteristics:
Steering Wheel Vibration
1. Steering wheel vibrates in the rotation direction. This characteristic is most noticeable when applying
brakes at a vehicle speed of
100-140 km/h {62.1-86.8 mph}
.
Floor Vibration
1. When applying the brakes, the vehicle body shakes back and forth. The seriousness of the shaking is not
influenced by vehicle speed.
Brake Pedal Vibration
1. When applying brakes, a pulsating force tries to push the brake pad back. The pulsation is transmitted to
the brake pedal.
2. The following are the main possible causes of brake judder:
Due to an excessive runout (side-to-side wobble) of the disc plate, the thickness of the disc plate is uneven.
1. If the runout is
more than 0.05 mm {0.002 in}
at the position
10 mm {0.39 in}
from the disc plate edge,
uneven wear occurs on the disc plate because the pad contacts the plate unevenly.
2. If the runout is
less than 0.05 mm {0.002 in}
, uneven wear does not occur.
The disc plate is deformed by heat.
1. Repeated panic braking may raise the temperature in some portions of disc plate by
approx. 1,000°C
{1,832°F}
. This results in a deformed disc plate.
Due to corrosion, the thickness and friction coefficient of disc plate change.
1. If a vehicle is parked in damp conditions for a long time, corrosion occurs on the friction surface of disc
plate.
2. The thickness of corrosion is uneven and sometimes appears like a wave pattern, which changes the
friction coefficient and causes a reaction force.
Inspection and Repair Procedure
2007 Mazda MX-5 Miata Sport
2007 BRAKES Conventional Brake System - MX-5 Miata
Microsoft
Thursday, July 09, 2009 3:18:52 PM
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© 2005 Mitchell Repair Information Company, LLC.