As a continuation of our previous blogs, this blog will go over premature even and taper pad wear. All pads wearing evenly but prematurely can be caused by the front brakes being overworked due a rear brake problem or front caliper problems or seized metering valve. Premature wear of the outboard pad is caused when the outboard pad is not allowed to release off of the rotor properly after the brake pedal is released. To help you diagnose this, we’ve prepared the following lists and images:
Even Pad Wear (All Pads Worn Evenly)
A. Accelerated pad wear (mild)
- Change in vehicle use from previous set of pads
- Front to rear brake balance not correct (i.e. rear brake(s) out of adjustment, restricted rear brake hose)
- Metering valve stuck on open position (Only applies to RWD’s equipped with metering valves)
- Calipers not allowing proper release of pads due to internal corrosion, seal rollback
- Inferior friction or friction not suited to vehicle use
Change in Vehicle Use From Previous Set of Pads
Front to Rear Brake Balance Not Correct (i.e. rear brake(s) out of adjustment, restricted rear brake hose)
Metering Valve Stuck in Open Position (Only applies to RWD’s equipped with metering valves)
Calipers Not Allowing Proper Release of Pads Due to Internal Corrosion, High Mileage OE Calipers, Inefficient Seal Rollback
Inferior Friction or Friction Not Suited to Vehicle Use
B. Accelerated pad wear (severe)
- Two Foot Driving
- Vehicle Being Used for Commercial Application (i.e. delivery, taxi)
- Venting not being allowed due to plugged or covered vent port in master cylinder
Two Foot Driving
Vehicle Being Used For Commercial Application (i.e. delivery, taxi)
Venting Not Being Allowed Due to Plugged Vent Port in Master Cylinder
Venting Not Being Allowed Due to Covered Vent Port in Master Cylinder
Taper Pad Wear
Top to Bottom Taper Wear
Floating/Sliding
- Binding in bracket or knuckle (can’t release)
- Seized in bracket or knuckle (can’t apply)
Fixed
- Pad end experiencing wear is binding in caliper housing
- Experiencing wear caliper piston not releasing (4 piston caliper)
- End of pad opposite the wear cannot apply due to seized caliper piston (4 piston caliper)
- End of pad opposite the wear cannot apply due to pad seized in housing
Inside to Outside Taper Wear
Floating/sliding
- Brake pad is binding on worn end and can’t release
- Brake pad is binding on non-worn end and can’t apply evenly
- Rear disc pad with piston locatin tab – tab not aligned with piston notch
Fixed
- End of pad experiencing wear is binding in caliper housing
- End of pad experiencing wear caliper piston not releasing (4 piston caliper)
Rusting of Caliper Housing Casting Hole
End of Pad Experiencing Wear is Binding in Bracket or Knuckle (can’t release)
Rear Disc Pad With Piston Locating Tab – Tab Not Aligned With Piston Notch
End of Pad Experiencing Wear Caliper Piston Not Releasing (4 piston caliper)
More Mechanical Help
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